sachs rotary gokart
#1
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From: clearwater, florida
sachs rotary gokart
This has been a year long project, which should have taken only about 2 weeks, if that. but here i am so far- Details - Was a honda 5.0 horse motor, now it is a sachs 303cc wankel motor. Makes around 17hp @ 6000rpm. I rebuilt this one, because a line that comes off the housing, to pass compression pulses to the carb so it can pull fuel from the tank (sachs way of making a fuel pump) was clogged, and there were no air pulses. So i pulled it, & cleaned the tube the air goes through, to get the clogging particle out, and it now works fine. However, it runs WAY rich, and this is a rebuilt, (atleast i think it went together correctly) carb, i believe i may need to put an adjustable valve in the line that the air pulses go through, that way i can regulate how much it pressurizes the carb. The exhaust is a custom 6'' header, and muffler from a harley davidson bike. Dunno any more details about it. Anyway, the motor drives the rear wheels (which have a solid rear axle, so its like a welded diff. ) by 2 v-belts, with an adjustable arm, to tension the belts and go. (like a clutch) Look for the lever in the pics, up by the steering wheel, it looks like a giant sword. Once i get new tires on the thing, and find out why it is running way rich, it will be drivable. If ANYONE has ANY info on these carbs, please let me know. They are tillotson, diapharm type carbs. As for how fast it will go? i have no idea. I know it wont acclerate that fast, due to the very top end ratio. The motor pulley is about 2.25'' dia., while the wheel pulleys are 6'' dia. So top end, if the belts do not slip and i can actually go wide open throttle with no slipage, should be very fast, however the acclerataion will not be. I'm not to into speed with this thing, at least not yet. i'm just into the whole coolness, and uniqueness of it. Enough talking, onto the pics!
also, here is a video of it running just after i rebuilt it
http://youtube.com/watch?v=UZrx2VrRcK0
also, here is a video of it running just after i rebuilt it
http://youtube.com/watch?v=UZrx2VrRcK0
#2
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From: clearwater, florida
heres a picture of the motor before being rebuilt, and while i had it apart, just before puting the end plate back on. You can see how much of the motor is cooling fins! the rotor is the same width as a 12A, yet about half the height. Peripheral port, too! The holes in the rotor are for the air/fuel charge to pass through before going thru the p-port. Thats how they decided to cool the rotor with air. The air goes through the carb, down the side of one side plate to the e-shaft bearings, through the rotor and rotor bearing, into the other endplate, and then up to the intake periport, and into the combustion chamber. Too bad it adds alot of heat to the intake air charge, about 50 degrees i think.
#5
I have one of these (still apart) in my garage. Its original home was in a 1974 Arctic Cat Panther snowmobile. The method of cooling (and lubricating) the e-shaft, rotor and bearings is known as "charge cooling"--- ie: the intake charge is first routed through the center of the engine before being directed into the intake port.
This engine requires a 40: 1 premix, and I can't recall if there's a way to lean out the mixture on these side-draft Tillotson carbs. But you'll certainly see lots of blue smoke with that 40: 1 premix ratio.
Of greater concern is the potential for overheating with your application. Snowmobiles usually run in ambient temps below freezing since they are a winter vehicle. But charge cooling on an engine being run in the middle of summer might be a problem.
This engine requires a 40: 1 premix, and I can't recall if there's a way to lean out the mixture on these side-draft Tillotson carbs. But you'll certainly see lots of blue smoke with that 40: 1 premix ratio.
Of greater concern is the potential for overheating with your application. Snowmobiles usually run in ambient temps below freezing since they are a winter vehicle. But charge cooling on an engine being run in the middle of summer might be a problem.
#7
Originally Posted by AbortRetryFail
Dude that's badass. That project has come a long way! Nice touch with the 'sachs' cap on the end.
Aviator 902S has got a point though, i wouldnt run it in the summer at all.
Aviator 902S has got a point though, i wouldnt run it in the summer at all.
There has to be a way to make this work because the idea of using this engine for go-karts is not new---- several go-karts were manufactered using these engines in the '70s.
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#8
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From: clearwater, florida
ya i try not to run it in the summer at all because of this. The hercules w2000 motorcycle had these engines, and they had changed the air flow to where the air went into the motor to cool it, and then exited, then going through the carb & into the intake port, to the combustion chamber. the vaporizing of the fuel helped to cool the air back down a little as well, after exiting the motor. Got to be a way to modify it for that to work
#9
So that was your motor! I ran across this video a few months ago. Very nice. A differant sound than what I'm used to. Will be nice to see it screaming down a kart track. Is it going in a shifter kart becuase hearing this thing running up through the gears would be amazing.
@London303
If you run the carb after the eccentric, won't you lose your lubrication to the main bearings, since they're lubricated by the premix?
@London303
If you run the carb after the eccentric, won't you lose your lubrication to the main bearings, since they're lubricated by the premix?
#11
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From: clearwater, florida
update time... you know how youll have a project thats been in the works for a while, and you get so giddy that you just need to drive it? well ya, happened to me today. I put both the v-belts on, & got another tensioner. Ordered all new tires. So i put it together, and im looking at it... damn i just gotta test it out. So i air up the tires... well 3 of them, the front drivers is flat. Also, the front 2 wheel bearings are gone, there are no ***** in them what soever. And the steering wheel was at a buddys getting repainted, so i used vice grips as a substitute. well i push it out to the street & fire it up. hop in, & start feathering the clutch/belt tensioner lever, and the throttle. i get up to about 20, & come to a stop ath the stop sign. hang a left, & another left on to the street behind me. on this road, it pulls to about 35, & now i've got the tensioner fully tight. the engine is just barely turning, maybe 2000rpm... "HOLY ****!!!!!" i yell i couldnt believe i was actually riding it!!!! i get back to my street, & hit it again. i got up to as fast as i had been going before... but didnt let off. i must have gotten to 40 or 45 mph this time, and got on the brakes cuz of the same stop sign. the motor was still low in the R's. by now, the v-belts had been slipping SOO much that one broke in half, and the other shrank, and wouldnt even let the motor idle! so i pushed it back home, more excited than i can ever remeber! come tuesday i'll have 2 new belts, all new tires, and already have my steering wheel. Next saturday we'll put it all together, and drive it, now that there isnt the horrible drag of 2 bad bearings & a flat, i think it'll actually go a while longer before killing the belts, lol. So i'll do my best to get a video to ya soon! thanks for checking up on me, lol
#13
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From: clearwater, florida
http://www.youtube.com/watch?v=tj0bg-rtO7Q
KART FINALLY DRIVES! clocked at 50mph (not in this vid, i'd say 35 in the vid) by my buddy in his 1st gen, and it was only at about 4000 rpm... haha it should hit 70-80... fun as hell! enjoy it, its been a LONG project for me, and i'm finally able to enjoy all the hard work... hope you all like it
KART FINALLY DRIVES! clocked at 50mph (not in this vid, i'd say 35 in the vid) by my buddy in his 1st gen, and it was only at about 4000 rpm... haha it should hit 70-80... fun as hell! enjoy it, its been a LONG project for me, and i'm finally able to enjoy all the hard work... hope you all like it
#16
Where did you find that motor. I am always on the look out for a rotary outboard motor, I think that would be cool!
But that is just awesome!!! More power to you and your rotorkart!
But that is just awesome!!! More power to you and your rotorkart!
#19
I used a km914a on my airboat, I used a prop designed for a vw aero engine, I used a honda city turbocharger and ran around 7psi boost, I had no reduction box and got about 2500-2600rpm out of it, It pushed the boat along at around 40-50km/hr, pulled the boat to bits last year as it had rot in the hull, still got the engine just havnt figured out what project to do with it next!
#23
i figure this is really old but i just fund out about this. i was going to ask when will some one turbo one of these.
i have a idea to help cool the motor down inject a water / meth in to it. that would help cool it down. i need to find a go-cart to use as a frame.
i have a idea to help cool the motor down inject a water / meth in to it. that would help cool it down. i need to find a go-cart to use as a frame.
#25
landon would you mind taking more pics as how you drive train is set up. a budy of mine is getting rid of a off road go cart and i want to see if i can do what you did to drive the rear wheels.