I got everything timed up (which is MUCH harder with a functional chain tensioner) and then prepared to put it back into the chassis:



But then I remembered that I had forgotten to install the high-flow oil pump. This small hole has to be drilled out to 3/36":



I forgot to do this at the optimal time (when the engine was apart), so to prevent shavings falling into the engine I used a lot of oil on the drill bit and then thoroughly flushed out the passage with brake-cleaner.

This is the OEM pump cover, which can be removed with two 8mm bolts:



The cover gets reused, but the bottom piece is replaced with this new one:



The bottom part of the pump is held in with more of these really soft JIS head machine screws:



Which regrettably had to be welded out. Fortunately the kit comes with replacements. What it doesn't come with are new o-rings, but I had a set of viton ones that fit. The old ones may have been reusable, but if oil is squeezing past them then that oil is not getting to the engine. Replacing them is good practice:



Then reassembly was reverse of removal. I also received the new oil pump screen:



Which I popped back into place before reinstalling the clutch cover:



Also, the TB120 kit comes with two ports on the cylinder head that can be used for an oil cooler. For my purposes I don't think a cooler is necessary (although I've been wrong before), so for now they just get plugs:



I added crush washers, since the plugs didn't actually come with any obvious means of sealing them.

Then the stator assembly can go back on, with a new woodruff key:



Regrettably I did not remember to get replacement bolts for the stator, and one of them is in miserable shape from when I initially took it apart (a chisel was required). I don't want to leave that long term so I'll have to pick up some suitable replacements.

I also put on the rotor, ignition coil (wired straight to the points still, for test purposes), exhaust, fuel tank, and throttle cable.

Then I popped the prior carb on with 110/40 jets (BBRs recommendation when using a 120 kit and an exhaust):



I have an aftermarket carb with a larger bore which is probably more suitable, but I didn't want to mess around with that for the first start since this one is a known quantity. I then put in some more synthetic 5W50 (which continues to somehow be cheaper than 20W50):



It's worth noting that I spent quite a lot of time flushing shavings out of the engine with mineral spirits while I had it disassembled. Once almost no more aluminum flakes were coming out I considered it good enough, and then before I reinstalled the clutch cover I of course blew out any of the remaining shavings that I could see. If you see shavings in some of the previous photos, I took them out before putting it back together.

 

I was pleasantly surprised - it started with only a couple of kicks and ran very smoothly. One thing I didn't expect is that it seems to be quite rich. With any choke it'll bog down and die. Without choke it will start and idle from cold, but I'm sure once it's hot it'll be too rich. This is probably a consequence of the fact that the jetting was intended for a bike with an aftermarket exhaust, and my exhaust is not only stock but also somewhat dented, which might restrict flow further. I think I need to fix the exhaust before I play with the carb any further, and then probably go down a size on the jets.

But hey, it runs! It also runs a lot quieter. I said that I didn't notice any chain noise initially, but I think I just wasn't familiar enough with single-cylinder engines to notice. I didn't hear anything obvious like a rattling or slapping, but I definitely notice a reduction in engine noise now. The only thing I hear are the rockers tapping away, and very quietly at that.

I ran it for about 2 minutes before shutting it off and draining some oil. I expected there to be aluminum in it since I couldn't possibly have flushed all of it from the ball-bearings in the bottom end:



Cleaner than it was before. Also there's a functional screen now to prevent it getting drawn into the pump. The design puts the drain bolt right below the screen so that when you drain it the first oil to come out includes any debris from the screen.

The plan is to keep draining a bit at a time and replacing an equal amount until it's coming out clean, then completely drain and replace it with a fresh fill.

I removed the valve cover to make sure oil was getting to the top end, and boy is it ever!



That doesn't really tell me if the amount or pressure is adequate, but then with no gauges or specifications to measure it's a bit of a black box. While I appreciate the simplicity of this bike, there is something to be said for a simple oil-pressure gauge.

Both valves needed to be loosened very slightly to meet the spec of 0.05mm, which makes sense since I lapped the valves a bit.

And good news, the new tensioner assembly is actually keeping the chain straight:



The lens distorts it slightly, but it is in fact straight.

I still have some more to do before I can safely ride it, but it felt good to put it all back together and actually have it work. Fingers-crossed it stays that way.

Until next time

 

I've gotten back to work on my Rx7, abdominal pain or no. It doesn't seem to be any worse when lifting things (actually it's better when standing), so I'm just going to monitor and if it's not getting worse I'll keep working. Plus most of the heavy lifting is done for now.

When we left off, I was still stripping the car down. First I had to remove the fenders, which wouldn't be difficult except that I think this fastener was tack welded on at some point:



It's hard to tell, but that's not a bolt. I think someone snapped the bolt off in the past when removing the passenger fender, and then when reinstalling they tack-welded the fender onto the remainder of the bolt. If that sounds like a stupid theory it's because it is, but I'll point you to the following evidence:

- There is literally no bolt head left, despite the fact that the rest of the area is not that rusty
- The paint in the area is darkened, potentially from heat
- When I eventually resorted to the flap wheel to remove this fastener, there is literally no seam between the bolt and the fender itself:



So I think it's a reasonable conclusion to draw, even if the action of welding a fender to the body is itself unreasonable.

That frees the fender. The metal under here is decent:



There's this weird area where a bunch of panels overlap that feels a bit like an afterthought on Mazda's part, and on both sides there is some surface rust appearing:



And there is some rust on the bottom as well:



Not pictured, but a screwdriver would later go through on the bottom. More work for me later. The fenders themselves have a bit of surface rust on the bottom but are in overall good shape:





I really like this paint colour (3A Royal Maroon Metallic) even if my particular car isn't a great example of it:



It's been resprayed at least once. The quality of the materials seems good, but it has the typical Maaco level of orange peel.

Next I pulled the door cards in preparation for pulling the doors:



This is technically optional, but removing them reduces the likelihood of damage and I'm well past the point of half-measures on this project.

My homemade vapour barrier seems to be holding up well:



I know that this is just a regular black S5 door card to most people, but I really love this interior piece in particular for some reason. I'm probably biased since I spent so much time figuring out how to cram 6.5" speakers into the doors.



I wrapped the cards up carefully using wide heavy duty saran wrap and put them under my bed along with the tail-lights. There are car parts under my bed, in my basement, multiple sheds, loft over the garage. Basically everywhere at this point.

I had to fish the window motor connectors out through the vapour barrier to roll the windows down, otherwise there's no easy way to handle the door:

 

I have no pictures of the door removal itself (my hands were full with the door, as were my brother's) but this absolutely requires at least two people to complete. Also for anyone reading this as an instructional (which you shouldn't), make sure you free the wiring harness grommet from the firewall side and also make sure to knock out the little pin for the door limiter, otherwise you'll find yourself holding a very heavy door that is still hung up on the car by that one small pin. Ask how I know.

Even if the car and doors are getting painted, it also pays to take a few minutes to tape up both the edge of the door and the door frame itself to prevent unneeded damage. You will end up making scratches otherwise.



Next I pulled out the body harness and somehow managed to contort it into a compact shape:





Many zip-ties are holding it tight, and it's been tucked away into a bin in my basement. I wasn't going to alter this harness but since it's out I will probably strip everything (including the area I re-wrapped), inspect everything and then re-wrap it. That also gives me an opportunity to integrate a thicker gauge wire for the fuel pump rather than the separate 10 AWG wire I've been using, integrate the hatch-popper wires, etc. That should provide a much cleaner result in the end.

With that done I put the car on jack-stands:



Uncomfortably high, in fact:



The safest way to do this would have been to remove the front and rear subframes including control arms, shocks, struts, etc. However for space reasons I decided to get the car onto the rotisserie stands before removing those parts. I bolted up the frame rail connectors that I showed in prior posts and then using a level I slowly adjusted the car upward on each side:



I didn't take pictures during this process. It took some 6 hours, due to an abundance of caution on my part and the fact that I misplaced the bottle-jack drill adapter I purchased for this project. I have since purchased another.

I can describe the general process using the following photo:



Right now the bottle-jack is on the outer height adjustment. The first step is actually to adjust the height of the car on the inner height adjustment. The inner raises the car, but it raises it relative to the centerline of the round pivot. This is important, because having the car not centered will make it tend to want to roll one way or the other. This is manageable but it should be avoided if possible.

I got it up to the point photographed, then rotated the car as much as I could and removed the front and rear suspension one component at a time. I had to get some help removing the diff (not super heavy, but awkward to remove when it's at waist height) and if anyone reading does something similar I highly recommend having a friend help with this for safety reasons.

I later adjusted the inner adjustment to it's maximum and the car is still slightly bottom-heavy. I think this could be mitigated by flipping over the two components that bolt to the part that bolts to the frame rails so that the receiver tube is on top. I'm sorry if the terminology isn't clear - I don't know what any of these parts are actually called. Anyways, the car is centered enough that I can easily rotate it 360 degrees, so I'm not really worried.

Then the outer adjustment (photographed) will raise or lower the entire car while keeping the centering the same. In this photo it's fairly low, but I could get 2-3 feet out of it if needed. In practice, it just needs to be high enough so that the car doesn't hit the long tube that ties the stands together:



Also remember to remove the fuel cap, otherwise you could end up striking it on that tube and bending the quarter panel.

With everything stripped (except front subframe because a bolt is stuck, and sway bars because I haven't figured out a place to put them yet) I could rotate the car all the way around and start working on the floor:





What a weird sight. It feels like some sort of optical illusion whenever I see it like this.

However, this makes working on the chassis about 100x more pleasant. It took a lot of prep to get here but the access to the floor is unparalleled. I immediately started chipping away the undercoating and cleaning the dirt, grease, and transmission fluid:



This would be easier with dry ice or something, but as I've mentioned in the past I can't seem to find it locally. So a chisel and a hammer is what I'm using.

 

Now it probably wouldn't be interesting to watch a bunch of photos of me scraping black goo from the bottom of the car, so I'm just going to post some of the problem areas I've discovered (most of which I knew about).

This area is where the back of the floor pan on the passenger side meets the upright panel just in front of the storage bins:



Rusty along the seam, as I figured it would be since there's a patch panel inside. This is one of my dad's repairs. I can't be that upset about the quality - it's safe, it lasted 9 years, and at the time these cars were almost valueless.

Someone (not my dad) also seems to have put a small patch panel under the frame rail and then hammered the rail up to retain it. That will have to be remedied. There's currently a frame-rail reinforcement from V8 Roadsters (intended for a Miata) bolted on top, but you can just see the dubious repair in the above photo.

This round hole is supposed to have a round metal plate on it attached with seam sealer, but instead there was a square plate riveted on:



Also done before I purchased the car. Not terrible, but as with most of the repairs there was little or no effort to actually remove the rust that caused the issue.

The below repair is one of mine. I think I photographed this area from the inside before, but essentially I removed a bunch of rusty sheet in this area without properly understanding the geometry. There is an inner floor pan and an outer, and this outer comes down from the wheel well and gets spot-welded on creating an empty cavity between it and the inner. When I did this repair (before I had a welder) I just took the outer and riveted it straight across the hole where I removed the rust, so there was a small hole in the interior floor that led into this cavity. This didn't result in a hole in the floor or anything, but it does mean that moisture from the interior carpet could find it's way down and seep into this area, which it looks like it has been:



Also at some point I must have lost this drill bit in the cavity:



What a find! This project might actually turn out to be cash-flow positive...

This is the aforementioned plate at the back of the passenger floor pan:



Later, after punching out the rivets on the bottom and removing the bolts for the frame rail reinforcements, I tried grinding down these terrible welds so I could remove the plate:



But at this rate I'll burn through the floor before I burn through the welds. Besides, I already know the metal under there is garbage. Once the frame rail itself is removed I'll just cut around this entire repair and replace it with a proper welded in patch.

Similar story for this other patch near the seat mount:





This one will probably be a bit trickier. I'll have to take some very careful measurements to make sure I put the seat mount back in the correct place after repairing the floor under it.

Also, the parking brake cable bracketry is pretty crusty:









Another piece that will need to be removed by removing the spot welts, de-rusted (if feasible, or replicated otherwise) and then reinstalled.

 

Here's a wide-shot of the area, with most of the undercoating removed:



A blurry one of another problem area. That hole near the fill tube goes into the rear quarter panel. I knew there was surface rust here, but I didn't know it had progressed this badly. I have yet to figure out exactly how I'm going to address this area, but I will.



The back of the dogleg area is also pretty rusty, and there are some holes appearing:



I think the only way to fix this is to section the rocker at the rear body molding and the front below the door hinge area, then drill out all the spot welds and remove the entire rocker. Then perform all the inner repairs as well as any necessary rocker repair before putting it back on. It's a lot of work but I think I can handle it. The floor and frame rails will have to happen first though, since it gives me access to view the inside of the rockers. Then once I have the lay of the land I'll figure out how to deal with the dogleg.

A better view of the parking brake bracket:



And then here's a few more photos of it on the stands, since it's fascinating to look at:







That's where it stands for now. I think next (other than cleaning the other side of the floor pan) I need to buy some steel tube and start reinforcing the inside of the car to prevent flex when I start cutting. Were I to remove the floor pan and frame rails without reinforcement, it could flex on the stand and then I'd have to figure out how to make everything line up again for reinstallation. I'm thinking two tubes front to rear on either side, connecting to the firewall above the floorpan opposite where it's welded to the front frame rails. Then maybe an X-bar connected to the inner b-pillar structure since I guarantee I'll need to take apart more of the storage bin area once I start digging in a bit. Exact plan is TBD, but I'm going to be slow and methodical about this part.

Until next time

 

yours is much less banged up than mine at least.
and less gooey too, i spent a while cleaning under the car, its not fun

 

Yeah, mine has about three layers. There's the original undercoat which seems to be rubberized but is so old that it's pretty crunchy, there's places where a previous owner did dubious repairs and slapped on some more rubberized undercoat about 1/2" thick (often without removing the rust), and then I added rubberized undercoat around 6-7 years ago when I first fixed the floor.

Then there are places where the transmission fluid from the shifter housing has turned the rubberized undercoating into a tar-like substance that smells like creosote.

When I'm putting it all back together I'm not sure what I'm going to coat it with. I've heard a credible argument that the rubberized undercoating causes more harm than good, but I suspect that the other options (bedliner or something else hard) will be more prone to chipping. I have plenty of time to make a decision before I get to that stage.

 

I've been silently watching this thread for some time, but i have to chime in and say well done. This is quite the labor of love. I find it super ironic how only a few years ago the only answer to these cars was the crusher or to let them rot in a driveway, to doing a full rotisserie style restoration today. It's very encouraging to see the effort to keep this one on the road, and you're doing a super thorough job.

 

like you say, there is no hurry, but the new Mazda's still use what appears to be the same stuff, but a lot less of it

 

Thank you! I appreciate your kind words. It's a little intimidating taking a car all the way apart, but it's also the only way to really be sure I get all the rust. I'm hoping to have it back on the road sometime next spring / early summer, although I have no illusions about the fact it will probably take longer

 

Now that I'm back to work on my car, I paused working on the dirtbike. I've still been doing small stuff (which I have yet to photograph) but one thing I hadn't dealt with yet is the rear brake. Not having a rear brake can be dangerous if I need to stop quickly so I finally spent 30 minutes fixing it:



It's bent. Now that much is tolerable, however:



One side of the little saddle has snapped off. This makes it impossible to use with the little cylinder thing I purchased from CMS, as the cylinder will just fall out. But there is a simple solution:



One washer from the hardware store (the factory defect on the bottom is actually convenient for my purposes). Then some quick welding and a lick of paint:



I also had to bend the rod back into shape:



I think I have the bends reverse of normal (the rod should bend toward the swingarm right as it leaves the pedal, that way it doesn't stick out and catch on things) but it is functional. I probably should have done this a lot sooner.

The oil still has some glitter in it, even after a few drains and fills. I'm fairly certain it's decreasing with time so I think it's still just residual from the timing chain hitting the case before the rebuild.

Otherwise things were going well, until I decided to play with the jetting a few days ago. I think I was running 42/108, and it felt like the top end was a bit rich. Which is weird since it felt fine when I first put everything together.

So I took it apart and tried 40/100, but it ran terribly. It even idled terribly, which made no sense as I didn't change the pilot jet. Then I tried several other combinations (including the original 42/108 that I was running) and I could still barely get it to idle. And then I stopped even getting it to idle. All that I could get out of it was the occasional backfire. I took apart and cleaned the carb under the assumption that maybe I'd somehow gotten something in there, but it looked clean. The filter looked clean too. I tried bypassing the filter just in case, but no improvement.

I figured at this point maybe it had jumped time, although with a fresh and properly tensioned timing chain I wasn't sure how this could happen. I popped the valve and stator covers off and sure enough:







At TDC (or very near it, I have the stator a couple degrees off in this photo) that little circle should be at the top of the cam sprocket.

I was wondering, how did it jump 3 teeth? That seems insane to me. So I set about adjusting the sprocket so all the marks lined up, properly tensioned the chain again, and I realized I couldn't turn the engine over. It was still rotating smoothly but looking through the spark plug I could see the piston interfering with the exhaust valve.

I spent awhile playing with it trying to puzzle my way through it, repeatedly saying to myself "This doesn't make sense unless it sheared the woodruff key, but I replaced it with a new one when I rebuilt the engine!". Well, colour me surprised:



It sheared the woodruff key. Even weirder is that the crankshaft nut was still tight. I'm hoping nothing too severe happened internally in terms of valve to piston contact. I didn't hear anything weird (the engine was turning fine before I attempted to re-time it) and the valves look like they're returning home just fine, but I don't have a good way of testing without removing the head so I'm just going to hope for the best and try replacing the key.

Actually, now that I'm writing this - wouldn't this just affect the spark timing, not the cam timing? The cam is timed to the crank by the two sprockets. The stator rotating 3 teeth would impact when the spark plug fires because the eccentric lobe inside the stator is what actuates the points, but I think the valves should be fine. I've done a lot of work on my cars but piston engines aren't really my area of expertise...

At the very least this gave me chance to check out the camshaft - I'm definitely sure it's getting enough lubrication now. I tried wobbling it up and down to make sure it wasn't wearing away the journals and there was no slack, yet it rotates freely.

I've ordered a set of assorted woodruff keys (OEM Honda is still available but I don't want to wait too long so I'm hoping the kit has a compatible key), some nylock nuts, lock washers, and I'll be using blue loctite as well as double-checking the torque on the nut this time. Here's hoping that fixes it for good

 

I replaced the woodruff key (with a liberal application of loctite to both the key and the threads for the nut). I had to adjust the breaker point again and then after that the bike started right up.

I think the jets I have in there currently are 45/115 (nearest I have to BBR's 45/112 recommendation for a 120CC kit) and it seems to start and run fine. I've noticed that it tends to smoke a bit if I rev it high and then let off the throttle (grey fuel smoke) so the 115 is probably a bit too large, although I also had to adjust the needle to maximum rich in order to prevent a bog when snapping the throttle open from idle so who knows. Either way the bike starts and drives fine now, and I might just have to adjust the main jet to get it perfect.

There are a few other things I fixed on the bike but had yet to post about, so I'll bring it up to speed here. For one I added a clutch lever so I could shift properly. The bike came with this plastic one in the box of miscellaneous parts:



It was kind of okay, although it felt a little bit bendy so I thought an aluminum one would be nice. I was able to grab an original XL100S handle and light switch, which is good since I didn't have the OEM part:



Unfortunately the bike it came from was clearly dropped, so the lever was bent and there was a crack progressing through it at the hinge side:





I bought some replacement levers on eBay and the quality is good, although the finish is a bit different:



Oh well. Meanwhile the brake lever has a lot of slop. Here it is when pushing downward on it:



Then up:



I think the saddle has been splayed outward some from being dropped, or maybe something heavy falling on the lever:



So I'll need to address that. You can also see the throttle cable is way, way adjusted out. This is because my OEM cable is broken and all of the ones that allegedly fit the XR100 don't seem to fit the XL. I'm not sure if the XR got different levers or if the no-name replacements on Amazon / eBay are made for a different year of XR/XL and they just list it for all years. I have one in the mail that looks like a better fit. The clutch cable is also a bit long but the NOS replacement I ordered turns out to be for a 79-80 model. So if anyone needs a NOS 79-80 XL100S clutch cable shoot me a message and I'll let it go for the same as I paid for it.

The throttle cable was actually much longer with the OEM carb. I didn't mention this before, but I've replaced the carb with a Nibbi 26. This was due to lots of feedback I'd read online that the 120CC kit really benefits from a larger carb, and while I didn't ride it much with the stock carb after finishing the rebuild, it definitely feels like the larger carb picked up some extra power. I did have to add a pod filter since the inlet is larger than stock diameter:



I intend to design a simple inlet boot so that I can install the airbox lid, but my 3D printer is out of commission. It's now about 5 years old, and I spend more time fixing the thing than I actually spend printing. A replacement with a better unit is in order, but first I had to upgrade my computer so the wallet needs some time to recuperate before I move to that.

 

I replaced the rear shocks as well. One was completely blown (as in I could wobble the shaft back and forth by at least 1/2"), and the other was mostly blown. These new ones from JBS are decent quality and feel good so far:



A heads up, originally I purchased a set of 400mm shocks. They were listed for an XL100S (I think 81 - 83). I didn't measure before ordering and when I tried to fit them they were quite obviously too long. I thought maybe a previous owner swapped mine for shorter shocks so a shorter rider could use the bike more comfortably, but then it turns out the swingarm would run out of travel well before the 400mm shock would bolt up.

I went back and forth with the seller a bit. On the one hand it did say they would fit an XL in my year, but it looks like in some parts of the world the 81 XLs did in fact get a 400mm shock like the earlier models. And on the other hand, I had also completely neglected to measure before ordering (which is always prudent to do for a bike this old). The seller and I settled on an exchange but return shipping would be like $125 before tax so it wouldn't be economical. He ended up selling me a set of 320mm shocks (listed for an XL80) at cost, which I think is a fair resolution.

So let that be a lesson to anyone in a similar situation to measure before ordering - and if you're ordering for an 81 XL100S the 320mm shock is the correct size. And if anyone is looking for a 400mm shock send me a message, as I have nothing on which to install them.

With the new shocks the bike feels a lot less dangerous. Speaking of which let's look at the wheels. The front has some rust, but it's purely cosmetic:



But the tires are pretty bad. The front is a "Duro" brand tire which is Italian for "hard". Fitting, since it feels like a rock:



It feels like the plastic wheels that come on those little motorized cars they make for kids. The tread is decent though.

In the rear is the same cosmetic rust:



I think some metal polish would remove it although it won't put the missing chrome back. I will also need to see if the spokes need adjustment. But the real killer is the tread on the rear tire:



The tread in the center is mostly gone. This leads to a very weird feeling that the bike has no grip when accelerating straight and it wants to slide out, but then when it starts sliding out it suddenly grips up and wants to drive in the direction it's sliding. Very disconcerting.

Then when I apply the rear brake it locks up very easily, until it again starts to slide out and suddenly feels like it hits a wall and the bike wants to flip onto the opposite side. Not sure if I'm describing that well. I went for a ride this morning while the grass was damp and it was a bit hectic at times.

It seems like tires in these sizes are still available so I'll be replacing them when I have the budget. The rear in particular - the front is only kind of bad. Also on the short list is the fact that I still don't have any form of kill-switch:



I spent some time greasing the kicker and stretching the spring on the ball-bearing. Now the kicker doesn't feel so sloppy, and it no longer falls down and hits my leg while riding.



And I popped the speedometer back on:



It's in crap condition like the rest of the bike when I purchased it, but it does work. The trip odometer is stuck at 555.5 and never moves but the speedo needle and the regular odometer are working well. I won't be replacing this anytime soon since it's XL specific and quite expensive. I think the fact that it goes to 120 km/h is cute - very optimistic. I'm curious to see what the new top speed is with the 120cc kit but I would need a tachometer for safety as well as a license plate so I could take it on the road - nowhere on my property is flat enough to safely exceed about 60 km/h.

And that's all for now. Until next time

 

If only I had the energy to do that to my 86 N/A and get my 93 VFR750 running.

Sadly, I'm going to have to wait till I am retired.

Keep at it man. . . Don't stop now.

RL

 

I'm continuing to clean the underside of the Rx7 when I have time. I've reached the point where scraping doesn't do much, so I've started using enamel thinner to dissolve the undercoating and wipe it away. So far the results are good:



This area in the tunnel is a bit of a pain - the contours make it hard to remove the undercoating with a chisel, and while the enamel thinner dissolves the undercoating pretty easily it can't dissolve big chunks:





I'm still making progress, it's just slow. The flat areas are coming pretty clean:



And I got the parking brake cable area clean:



The rear hatch area it was more dirt / grease than undercoat, so it was still a lot of wiping with the enamel thinner but not much scraping:



And the bin area came out pretty clean as well:



While this is tedious and time consuming (and the respirator makes my nose sore), cleaning this as best as possible with the floor still in the car is preferable to trying to clean the floor when it's off the car. I'm going to clean everything I can reasonably get to with the car still assembled and then proceed to disassembly.

Here's another repair, not sure if I showed this one off yet:



This one I actually paid someone to do when I bought the car. The hole here prevented it passing inspection. It was only $120 (in 2016 dollars), and I remember the guy was very proud of the fact that he replicated the floor contours. While I definitely appreciate that I think it would have been better to dedicate that time to actually cutting out the rust instead of putting undercoat on top of it...

I also found something concerning. There's rust at the driver's side subframe mount, which is not unexpected, but it looks like the subframe mount was actually pushing upwards into the body:



Here's the passenger side for comparison:



While this project continues to increase in scope, I'm also more and more glad that I took it apart rather than just fixing what I could see. Otherwise I'd be in for a lot more work in a few years. I'm many hours into the floor cleaning part of the project at this point and have many more ahead of me, but I'm definitely past the halfway point. Then I can start the metal work.

 

Hey bread, try some Oven Cleaner for the undercoating in the tunnel. You want the spray can that foams up. It can dwell on the surface and is a bit easier to work with than straight enamel thinner.

 

Unfortunately the oven cleaner they sell here in Canada doesn't seem to work like it used to. Presumably the ingredient that acted as a solvent has been outlawed. I'll give it a shot though - just the fact that it dwells on the surface might help since I can spray it on and let time do the work.

 

There's also a minor bike update. I've had a set of replacement steering shaft bearings for a couple of months, but I've been procrastinating about replacing them. Turns out I shouldn't have been procrastinating since it only takes around an hour.

The first thing I did was remove the speedometer and handlebars, and then bend the tabs on the retaining washer and remove the top nut (which was loose, by the way):



That nut doesn't hold the steering shaft together or anything, but it does tie the top of the shocks to the steering column so it definitely shouldn't be loose.

The shocks will need a rebuild soon too. It seems straightforward enough to replace the fluid, but I have replacement seals too.



The fluid inside smelled pretty bad. Gear oil always smells bad, but this was particularly bad. Shock rebuild is on the to-do list.

The steering shaft is actually held into the sleeve by this weird nut:



I don't have the correct tool (some sort of spanner?) to remove this, but a set of vise-grips was able to do it without much issue. After that I could take a look at the old bearings:





Yup. Completely destroyed. No wonder there was so much slop in the steering - whenever I applied the front brakes with any speed, I would feel the shaft slap back and forth inside the sleeve. Some of the ball-bearings were rattling around loose inside the sleeve, as evidenced by the fact that the steering shaft has clearly been rubbing away on the upper race for a significant amount of time:



This looks pretty bad, and if I had a spare I'd swap it. But functionally it should be fine as long as the bearings are replaced. I didn't take photos on reassembly since my hands were covered in the red grease, but the kit fit perfectly and came with a new top nut and boot:



One nice thing about the new bearings is that the ball-bearings rode inside a cage that prevented them falling out. I don't think the original bearings had a cage (or if they did there was nothing remaining). This seems like a small thing but it made assembly much more pleasant.

I took a long ride after that, and the bearings made a huge difference. The most noticeable thing is that now the bike wants to go straight. The slop in the steering acted very much the same way as having lots of front toe-out in a car's alignment - it was very happy to start turning, but in a straight line it had more of a tendency to wander and the returnability of the steering wasn't very decisive. Now it definitely wants to be going straight, and turning (particularly during tight turns) feels much more solid. Also when I press the front brake I feel the forks compress rather than just feeling the steering shaft slap around. This kind of solidifies the need for a fork rebuild. If I were using this bike for competition I would want much stiffer springs as well, but for my purposes fresh fluid and seals is going to be enough.

The oil continues to have glitter in it. I've checked the camshaft journals and the timing chain and there's no sign of any wear there (other than what was already in the jug from the old chain). I popped off the clutch cover for a brief inspection:



Nothing seems to be grinding here. The inside of the cover shows nothing unusual, except some dust in the oil residue



So there's still no sign of anything interfering. Meanwhile the mesh shows almost nothing in it:



The dust coming out is much smaller than the holes in the mesh, so I assume it's just squeezing its way past. The fact that I can't find any indication of where it's coming from leads me to believe it might STILL be residue from before the rebuild. I did some google searching and found one guy who said he put a filter into the oiling loop by drilling into the case, and the filter collected 2 tablespoons of aluminum dust. This was after he replaced a timing chain that was slapping the case like mine was. He also said that he only had about 2mm of timing chain wear in the jug, and I definitely had more than 2mm, so I might have even more aluminum than that hiding in all corners of the case, getting washed out by the fresh oil every time I change it.

I'm going to pop off the valve cover once more to inspect the chain again, but otherwise I guess I just keep draining and filling.

 

I tried to ride the bike again tonight only to find that I had lost spark (again). I tested and found the coil wasn't sparking, so I figured it was probably new coil time. But no aftermarket coils I've found have worked, and NOS coils are like $500...

I took the coil off to test if it coil was in spec (since it might be the condenser), but then I found this:





Yup - the condenser wire has been spliced and soldered before, and whoever did it was too lazy to actually add any heat shrink so it occasionally hits the body of the coil. The charge is then taking the path of least resistance and grounding out through the body. I suspect that the dirt on the coil body has been partially insulating which is why this issue is intermittent. I just wrapped it in electrical tape as a test, and now it sparks again.

I'll have to clean everything properly and add some heat-shrink to this joint, but hopefully that solves it.

I also have a replacement triple-tree on the way, since a person over on GRM informed me that mine might be worn past the safe limit. I think it would have been fine but I was able to find one cheap and in Canada (avoiding customs charges), plus mine has some mismatched fasteners and the previous owner had a tendency to ram imperial fasteners into metric threads. Also the new inner tube should arrive soon for the rear tire, and I have fork oil for the front (since the gear oil in the forks is absolutely not the right stuff). I swear, the previous owner of this bike must be the worst mechanic ever.

Until next time

 

The pictures of the FC on the rotisserie in a fairly suburban looking garage is unhinged. Very ambitious!

 

Bro the hinges are gonna fly off with this build!

 

Thank you both for your kind words. I count myself lucky, I have a double garage and a family willing to put up with my constant automotive scope-creep.

 

I'm continuing to chip away at the Rx7 undercoating (pun intended). Time has been short. My friends and I competed in a hackathon this weekend (we got honorable mention, I'm proud to say) and next weekend is Canadian Thanksgiving + three birthday celebrations. All that to say, Rx7 work has been slow lately.

A few weeks ago I replaced the rear tire on my bike, but didn't have the time to write about it. I'd read some horror stories about how hard it is to change tires without tools, but in my case it wasn't really that bad. I watched a 10 minute YouTube video and then just grabbed a few different prying tools and screwdrivers and went to it. Removing the old tire took only about 20 minutes, including removing the wheel from the bike:



This tire is garbage. The front has some tread left (although the tire is definitely old and hard) but this one has nothing at all in the center. It's definitely easier to remove the rear tire when you aren't overly concerned with scratching your rims:



Pre-scratched courtesy of the previous owners. I was careful to not add to it unnecessarily, but I also wasn't too worried if I scratched it a little bit. There's quite a bit of rust in here in the bead, but since these are tube type wheels I'm not worried about it.

Old vs new:



I grabbed a motocross type tire rather than a DOT approved one, since this bike won't be street legal again for awhile (if decide to do it at all). For driving on my property or possibly on local paths, the motocross tire is much chunkier:





I also grabbed a heavy duty 3mm tube. I'm not likely to slam this wheel over rocks often or anything, but I'm also not overly concerned with weight so adding some extra thickness to the tube wall is a no-brainer.



Reassembly is the reverse of removal. It took maybe 40 minutes to get everything back together. It isn't nearly as bad as people make it out to be, and I didn't even remember to lubricate the bead. I think what happens to most people is they forget to use the ridge in the middle of the wheel to help roll the bead onto the rim. I'm pleased to say it now holds air and the bike is a lot less squirrely with a proper tire.

I took today off of work to rest after the hackathon. Last year I neglected to do that, so I went to work on the Monday after sleeping a cumulative 8 hours over the entire weekend and coding 12+ hours both days. Not a good time. Anyways, my plan was to rest but on Friday night my brother mentioned to me that someone on Facebook Marketplace was selling a big box of assorted bike speedometers for $50. For reference, here is the speedometer that came with the bike:



Glass is broken, body is completely beat, trip odometer reset **** is snapped off the side and the trip odometer itself is completely dead. But hey, at least it worked. I had given up on finding a replacement for the time being since they're hard to find, but looking in the box of speedometers I saw one that looked suspiciously similar. The seller dug it out and took some pictures, and near as I could tell it was identical. He lives 2 1/2 hours west of me and I wasn't in the mood for a long drive, but I wasn't going to have time to go get it anytime soon other than today and the price was too good.

Turns out he lives right near Lake Huron, so my brother and I made a day of it and drove there in my mom's Miata:



Unfortunately I didn't bring my real camera, so I only have phone photos, but it was beautiful. While I was there I also found a similar Honda speedometer (I think from an earlier XL100 model, since it's a plastic lens and integrates the turn and neutral indicators) and my brother found some Yamaha gauges he was looking for. All for $30 - the seller has had these parts for years and they weren't selling anytime soon, so he was happy to make a deal and see the parts go towards fixing someone's projects. Very cool dude.

Here's the speedometer I was looking for:



Basically identical to my current one. I only now noticed that it's graduated for 6 gears rather than 5, so it definitely isn't from an XL100S. I was vaguely concerned that it was broken since the trip odometer said 30 but the main odometer said 8 when I got it. I figured it had been knocked around a bit, hence why I also picked up that earlier model I mentioned before. But then I realized that the trip odometer reset works differently on this speedometer than the ones I've seen before - you don't press it, you rotate it and it progressively rotates the numbers around until you get to zero. So I think the indicated 30 is from being bumped around in the box.

Speaking of which, look at the colour difference on the trip odometer (which was resting with the 0 up when I got it) and the main odometer which I've wound forwards a bit here by riding the bike around:

The odometer definitely spent a very long time at the same mileage in direct sunlight. I think those were 8 original kilometers. I strongly suspect that someone took this off of the original bike with near zero mileage on it and put it aside. I can't speculate as to why (racing maybe ?). Then it spent a few years in the sun somewhere, banged around the sellers big box of speedometers for a few more, and then I bought it. I think it's basically new.

Other than the needle bouncing (which was quickly fixed with some silicone lubricant) it worked perfectly. It even cleaned up nice:



I also tested - with the original speedometer I see an indicate 600m of travel from the front of my property to the very back. This speedometer is exactly the same. So I think the gear ratios are identical. I also find that with the 120CC kit the bike winds out most gears really fast (particularly first), so the accidental change in the shift points is actually perfect for leisurely riding. Obviously I still only have 5 gears and the ratios haven't changed, but these shift points feel "right". I'm wondering if whatever bike this came from (XL125S maybe?) had the same ratios for the first five gears. Now that this bike has a bit more displacement, it's happy to shift lower while still being in the power band.

Sure it has a few nicks and dings, and there's some stuff (mold spots?) on the inside of the glass. There's also no non-destructive way to disassemble this unit so I can't clean it out. But for about $6 (since we got 5 gauges for $30) and 5+ hours of driving, I'm really happy with it.

Lastly, not exactly a part of the project but maybe of some interest, this grouse keeps jumping in my path when riding down the hill in my backyard. He (she?) has been doing this for days. He makes his way in front of the bike and waits till I come to a stop, then walks around and looks at me. If I get off and walk closer he runs away into the brush. Today he followed me into a clearing and walked around me for awhile watching:



Later he flew past my shoulder while riding and up onto our shed and watched me from there. I'm not sure why he's so interested - maybe when I'm engine braking down the hill the exhaust noise interests him for some reason? Weird.

Anyways, this post has been a bit long winded for not much progress on the project. But overall this was a good way to end the weekend. Until next time

 

this might be a little rabbit hole, but the thing that holds the meter together is just crimped on. if you're really gentle you can take a little like a pocket screw driver and uncrimp it, and then its apart.
i've had a luck with my Greddy gauges