I think I finally figured it out why the car won't start. Unfortunately it's not my wiring, it's the orientation of the dizzy drive gear. When I try to put the dizzy in, it's not very easy, and always moves the reluctor counterclockwise. About 20 degrees or so. I hate to say it but I am likely going to tear the front cover off and orient the gear the right way. The bevel side goes towards the rotors right?

I have a bore-scope camera, so I can see the gear, would that help if I give a description based on what I see? I'm just not looking forward to taking the e-shaft bolt off ect. with the motor in the car.

 

Progress! Sort of!

I got a good timing light, and checked timing, I'm right on, so no teardown of the engine for now.

I took GSLSEforme's advise and stopped using the choke. It almost fires. Then I remembered I'd swapped the primary slow air bleeds from stock 180 to 120 per Jeff20b's Nikki build thread. But I kinda forgot I'm at 5400 feet above sea level! So I put the stock air bleeds back in. It's trying to run, even backfired. So somehtign tells me I'm wetting out the plugs, even with 1.5 psi. I wonder if the floats are sticky again...ugh.

Is there a decent way to see the Quality of spark, with the plugs in the block? I'm wondering if I'm getting good spark. I ohmed out the plug hole threads, to ground strap and came out with .4 ohms.

 

I don't think that a timing light will confirm whether or not the drive gear is installed correctly.

Take the cap off the distributer and spin the engine over by hand. Note which way the distributer turns. That'll let you know 100% for sure the gear is installed correctly.


BUT running fine for 20 seconds then stuttering off is a typical sign of running out of fuel in the bowls.

 

Clay,the quality and color of spark you see while testing plugs externally will be the same with plugs installed in the engine,there is no reason to believe otherwise.

 

The distributor will turn the same way(correct) regardless of how drive gear is installed,if installed backwards,will be difficult to get dist. in engine at TDC and have reluctor and pickup aligned properly. It will always be what appears to be a tooth off,dist. can be removed and bumped a tooth either direction and rotating distributor body far enough to get the engine to start and run and set timing as close as possible-but the engine will run... The drive gear has a chamfer that is installed toward #1 rotor-or to face to the back of the engine.
In working with op it is determined the gear is correctly installed and this is verified if you look closely at the pics he's posted and the series of pics i've posted for comparison for correct TDC,dist. placement and reluctor/pick up correlation.
His use of timing light while cranking engine over and light showing leading ignition firing right at leading mark on pulley/indicator pin further verifies this.

 

It's very difficult to get an unknown engine to start and run while changing ignition system,modifying carburetor,etc. Much easier to get a rotary up and running in original configuration,then begin doing mods one at a time once you have a baseline in a known good running engine. This way when something doesn't work right or the engine no longer runs,you KNOW what caused it and can go back and figure it out-this applies to any engine,not just a rotary.
In communicating with op,it is now established he has good spark at the right time,has checked compression and deemed adequate. This leaves fuel,and flooding which is the complaint. The next step,if possible,is to install a stock carb for now(from a known good running engine) to rule out problems with the modified carb now on engine-to rule it out as the reason for no start.
Maybe someone on here local to him through goodwill could loan him a good carb to try to start his engine for diagnostic purposes. I would do so but not in possession of any these days.

 

The .4 ohms you're registering on ohmeter is likely the internal resistance of the meter itself. Touch both - & + leads together and see what you get for a reading...

 

Did some more testing tonight. I'm only getting 250 rpm cranking speed, according to my dwell-tach.

Also interestingly if I'm reading the FSM right, my 95 psi compression is great because I'm at 5300 feet.

While I had an assistant cranking the engine, I watched the venturies, and I see 0 fuel coming out of them. the only fuel I'm seeing, is from the accelerator pump shots, which comes out as a stream, not a mist. Shouldn't the venturies be making a mist? If the only fuel getting into the engine at cranking speed is a stream, i.e. not vaporized, that would likely explain the wet plugs and no start?

I took my air compressor and blew into the venturies, and they misted fine. I think I'm not getting sufficient air velocity through the booster venturies to pull and atomize fuel properly! I also attempted to hook up another vehicle to the 7 to charge the battery and this resulted in a minimal increase in cranking speed, but no start. I smell partially burned fuel coming out the exhaust as well at that point.

 

250 rpm is good

 

At cranking speed you're not going to see anything coming from venturies-not enough air going thru carb at cranking speed and idle speed. Car is basically dependent on idle circuit to start,idle+ choke to limit air and make mixture richer when needed for cold start. Will not see anything from centuries til throttle is opened air speed is increased thru centuries which pulls fuel with it,to simplify.

 

So something showed up in the mail today!



That's a 48mm downdraft Weber clone by Empi. The casting looks really good, linkage all good, ect. The Manifold is the Racing Beat one. Any good tips on feeding the OMP into this thing?

I'm a little disturbed by the casting quality on the RB manifold, just look at that step!


Oh and I uh picked up another motor! Yeah I know, I have too many motors in the garage now, but how often do you find a complete 4-port 13b with the original Hitachi carb? Supposedly it has only 60k on a rebuild? the aluminum inside the engine looks pristine, so I think it's been apart. Likely need serious decarboning/new apex seals as I find little to no compression on either rotor.

I finally got fed up with the ugly *** stripes (Yellow Orange and White!) on my hood/car and am flat blacking the hood. Car will likely be Silver.


I've been busy, but like usual work takes precedence.

One last thing. Since I put in a new battery lead to the starter, I retried my compression test (I forgot to hold open the throttle plates doh!), and got 115 on the rear rotor, and 95 on the front. Good for 5280 feet right?

 

I've got a RB holley manifold for that 13B engine if you are interested.

 

I've got a RB Holley 600 carb for a 13B engine if you are interested.

 

Thanks for the offers for the Holley jits, but I don't think I'm going to do anything with the 13b just yet. The flywheel is badly cracked on the friction surface,I've never heard of that happening before!

Also did a more complete compression test, with the schrader valve removed. I got 95 psi max on all 6 faces, so I'm pretty happy. Remember I'm at 5280 feet.

Look what's on my 12a!


I also went through the ignition system again, somehow I lost spark? I tested the modules and was getting all sorts of odd readings/no readings. Maybe .3 volts DC output. So I said screw it, got some Accell Modules and wired them in. I put about a 1/2 tablespoon oil down each open throat and the 7 now runs! I'm super excited. It won't idle, but I can feed it with the accelerator pump. Sounds freaking loud with only the header, my ears still kinda hurt unfortunately.

I've tried finding info from EMPI themselves but it's sparse. It's like they don't even know they make carbs...My guess is float level is out, or idle mixture is too lean? I'm feeding it 4 psi fuel atm.

Note to self, I really need some exhaust on this thing!

 

Is the EMPI carb used or new? Used I could see something clogging the idle fuel circuit. If its new open it up and make sure it doesn't have any packing kernels in the bowls. I can't recall if it was EMPI or some other company but I heard a story of new carbs being sent out with packing kernels in the bowls which would cause an idle circuit to clog up.


Yeah, rotaries are extremely loud.

 

Yeah it's a brand new, direct from manufacturer carb. I'm reluctant to open it atm, as I'll likely need a brand new top plate gasket, which of course will take some time to get here! But it did cross my mind that there could be stuff stuck in one of the circuit jets/passages.

 

Been messign around with the carb, and wanted to build the parts so I can use my existing throttle cable and OMP.

First I made a bushing so could fit the OMP lever thing onto the IDA shaft and not have it flop all over:


Then I narrowed teh OMP lever so it would mess the water outlet. Just sawed it in half, and welded the shorter pieces back together:


Surprisingly the Throttle lever just took a tiny bit of sanding and it fit right onto the IDA shaft.

I've connected the OMP to the new IDA with a cable, which I forgot to take a picture of. BTW, what does the OMP look like when it's at full throttle, in regards to the arm position? I just want to make sure I've got it operating correctly.

I took everything apart I could find on the carb and this is my baseline:

Idle Circuit: 120 airs correctors, F10 .70 Jets
Main Circuit: 120 air correctors, F7 emulsion tubes, 135 jets
Fuel Inlet Needle: 200
Fuel pressure: 3.75
Idle screws: out 1.5 turns
Progression holes: 3
Venturi Size: 37mm

Still can't get this thing to start reliably, or at all without choking one of the venturies with a hand while a helper starts the car.
I've noticed a large difference in vacuum through the venturies, with oddly enough the venturi leading to the housing that I tested peak compression numbers on having the lower vacuum?

 

Remember how I said it was hard to start, and I could feel a definite difference in vacuum between venturies?

I had a major vacuum leak! I took the manifold off, to check the gasket, put on a new gasket, with permatex copper on both sides. that's when I noticed RB had not plugged the odd M10x1.25 hole in the side of the manifold! I had a .40 inch hole in the damn manifold! No wonder it wouldn't pull any vacuum/fuel!

I put a bolt in the hole (damn Ace hardware wanted $1.70 for one bolt! And Auto store wanted $3.50!), and now the car starts pretty easily! So excited. Even got it to idle around 850 and smooth out.

Now I just need a muffler, as 120 decibels is too loud.

 

I got the exhaust put on and it sounds awesome! nice and quiet at idle and mean sounding as the revs climb. It's late but I'll write down some part numbers in case anyone else is interested. Been fighting with my DD, so I've not messed with the Mazda as much as I'd like.

Oh, before I forget, does anyone have a good idea of what the OMP looks like at rest and full throttle lever positions? I just want to make sure I've adjusted my cable linkage correctly.

As promised here's a parts list:

Magnaflow Cat MPE-94016

Pacesetter Headers PSM-70-1070

Vibrant resonator VPE-1793

Magnaflow Muffler MPE-12616

Total cost $382. Durability???. Sound Excellent. Emissions legal, probably.

 

Been a while eh?

In the meantime I've gotten into the brake system, bought new front calipers, and a rebuild kit for the rear. Turns out no one anywhere seems to have the rears in stock for some unknown reason. Oh and good luck finding the inner front bearings and races for the front spindle. Took a lot of hunting for that. No wonder people build Chevies.
Also turns out the anti-rattle/hardware kits are almost unobtanium too! Mazdatrix and Atkins both want nearly $50 for $5 worth of thin sheet metal...NO auto parts near me seem to have the clips so I'm reusing my salvageable ones.

 

The inner bearing on the car is just a tapper bearing you should be able to get the measurements off of it and get one for a trailer. I've never had to replace mine, so I've never had to look.

 

Trailer bearing hmm? Well I did find them, eventually, Rock Auto I think. I was just surprised they were so dang hard to find. Thankfully the Remanned front calipers included the pad holding prongs, so I used those and was able to salvage the parts from the rears.

Aww Yeah, shiny red calipers!


I'm working on the rears too, and came across this:

Is that OK, since the seal rides on the front part of the piston I don't think anything will happen?
It's really quite the b!tch trying to get the parking brake lever rods to line up with the actuator on the back of the adjusting rod. I tried compressing the stack of washers with a flathead and pushing the rod in and it just doesn't seem to be working. Meanwhile the cylinder inside of the piston is rotating now when I try to tighten the adjuster down any further, did I break that?

 

Master Cylinder was bad. Booster maybe bad. NewBooster and New (not remanned)master cylinder is doing better! I have some brakes, sort of!

OK so I bled the master on the car, and everything was looking good, no bubbles. Then I hooked up the lines, and I had a nice HARD pedal. When I went to bleed the system for the other 3 wheels, I noticed I started having a mushy pedal. The car will stop but not all that well. I'm at a loss now as to why I'm not getting good brakes! I may try rebleeding the system, but I'm not sure if that's the root cause. Would a mis-adjusted booster rod cause this? I'm doubtful that;s the cause as I was getting a hard pedal before I attached the other 3 wheels.

On the upside the car looks great with the 4 new totally useless red calipers.

 

1st make sure your pushrod is adjusted correctly. What is your bleeding procedure? Should be RR-LR-RF-LF. Are you having someone pump brake pedal? Should be pumped slowly 3x and hold,pumping too quickly introduces more air into system you're trying to get air out of. Are you still getting air out of various bleeders? Smacking calipers with rubber mallet can help to dislodge air bubbles during bleeding. Have all caliper pistons moved(out) brake pads up against rotors? Try gravity bleeding,put suitable container underneath each caliper and crack open all bleeders and let drip for several minutes,maybe 20. Put some hose on bleeders so brake fluid doesn't run down caliper body and ruin your paint job. You have my # if have questions.

 

I just spent god knows how much time reading this thread from start to finish. Keep up the good work Repuguy! Your perseverance has inspired me to try my hand at rebuilding a 12a sooner rather than later. I'm equally impressed at the quality posts from the other forum members as well.