Mystery 433cc Yamaha Sno-Jet engine find ....Mustie1 dedication
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- čas přidán 12. 11. 2014
- This is a copycat video dedication to CZcams publisher "Mustie1" who's my inspiration on getting little engines to run. I do believe this to be a 1972-73 Yamaha 433cc SS sno-jet with a pull start, points, no CDI, dual carbs, and single exhaust. but, I could be wrong.
- Auta a dopravní prostředky
This engine came out of a 1972 SnoJet 433 SST Snowmobile when you saw the SS on engine block it was a abbreviation it’s a true Yamaha SST 433 engine
This is the correct answer!
I had a1972 Sno-Jet 433 back in the 70’s bored 60 over nothing on the Lake could keep up with it
that would make a great micro car or gokart, and thanks for the shout out,
That's a regular 433 used in Yamaha, Snojet and roloflex machines, you need the rest of the tin work that goes around the cylinders for the fan cooling to be effective
Running a long stored dried out 2 cycle engine on ether scores the cylinder, rings, let alone crank bearings and piston pin bearings needle bearings. Never should use ether on anything other than to start a wet engine or a diesel when it is super cold. Dries out the cylinder walls the second it hits the combustion chamber.
Doesn't need the battery, has charging (dc circuit charges ignition) and lighting (ac for lights) coils under the flywheel, ignition system is self contained. Probably the back feed from the battery fried the varnish coating off the bare copper wires in the charging coil.
It is an early 440 off a Sno Jet snowmobile, most likely an Star Jet or Astro Jet. Exhaust does not look like a Sabre Jet, hood was open in the center and the Sabre Jet had different exhaust that had it set lower to be less visible and a chrome air shroud over the heads (which is missing on this engine)
Sno Jet manuals put the horsepower at 30 for single carburetor, 32 HP for dual carburetors. Carburetors are Keihin (Key-In). Reliable engine but has multi piece drive unit (torque converter) on the engine because Yamaha had a long crank with a bunch of splines and the drive TC was made in pieces. That was what one thing Sno Jet buyers disliked because they couldn't use any other TC drive unit for better performance because the Yamaha engine did not have the standard 30mm tapered crank for standard drive clutch.
And stop running it without the air shrouds, It will overheat nearly immediately. The air from the fan on the flywheel has to be directed over the heads and cylinders. There is a 3 pieces shroud that covers the top end. Include head cover with plug access holes, front piece that goes over the exhaust side and a rear piece that goes over the carburetor side.
My dad used to sell Sno-Jet's in the early 70's
That came out of something quite (fast) sporty, because it's got dual carbs.
It might have come out of a Sabre-Jet they were fan cooled and kind of hot but not for racing.
The SST had Free Air heads and dual exhaust if i remember. And your compression sound ok.
Worked at a Sno Jet Dealer and raced a few different models in the 70s and 80s. Don't recall ever seeing any of the early 70s Sno-Jet models other than the Thunder Jets that used a jack shaft drive. All those I ran had Free Air only engines.
My fathers old 72 Super Jet had this engine in it. It used to be parked under the portion of his shed that is now his small shop he parks his atv in. He had it propped up on cinder blocks for the longest time. I remember going in there during summer as a kid and sitting on it and pretending to drive it. The seat was always kept off of it and stored in my grandfathers basement. Sadly he scrapped the sled years ago. He didn't know at the time there were people who would go in and replace the in-chassis fuel tank.
I'm referring to the "companion pulley with the disc brake on it" he is showing in video. That shaft setup is not from a Sno-Jet sled of that engines period other than possibly a Thunder Jet.
Was the Thunder Jet a sled made under Kawasaki after they bought Sno Jet? I don't have much experience with snowmobiles. My family only owned two sleds. An Arctic Cat my grandparents owned and my fathers Sno Jet. Their AC was sold before I was born and my dads Sno Jet was out of commission when I was growing up. :)
Never mind, I found some videos of one. Kawasaki didn't buy Sno Jet until the mid to late 70's. The Thunder Jet was a race sled from what I gather. :)
Reminds me of a Trabant engine underneath the cooling tin.
I noticed that the cylinder design, on the outside, is quite similar to the early seventies Yamaha RD motorcycles. Based on that I would expect about 40 to 45 HP. I think for a two stroke that old, 100 psi is promising. Good luck with your find! BTW, shouldn't there be some air duct cover for the engine cooling? The cooling fins on the cylinder heads suggest so.
73 GP 433
My uncle had a Yamaha 433gp, super fast for the time. We had 290 snow jets with one having a matching trailer. Very cool machines.
Sounds good..ideal for a micro as you say, can't wait to see what you do with it. My guess is about 38/40hp with the twin carbs. I think a lot of these engines are used in hovercraft too.
Don't know what the battery was for, because the magneto ign is self energizing,
like a lawn mower engine.
There should be 2 wires that go from each set of points to each coil, a lighting coil wire that would go to the lights and 1or 2 wires that are used for a kill switch and possibly 1 ground wire. Ether can cause the cyl or head bolts to pull the threads from the case and that will give you some really low compression :-)
hmm. now you got me thinking. I downloaded a schematic, but it didn't make sense. I couldn't get spark without the battery, at least I thought so. I wonder? wiring = red, yellow, black --- orange to coil one, grey to coil two. I connected 12v to both coil wires together and got spark .I didn't even think magneto. hmm
2stroketurbo
This is the closest I could come up with, orange and grey are ign, black is ground, yellow and red are lighting coils.
www.vintagesnow.com/Yamaha_files/74_sl338f_SL433F_WD.pdf
What you have there is a Racing Engine off a 1972 YAMAHA SS, Which is one of the Rarest YAMAHA'S you could ever own!!! My suggestion is find a chassis lacking the engine and re-join them together AND HAVE A REAL Racing SLED!!!
Nice little engine. And a nice shout out to Mustie 1 . I love his videos too! Everyone should check em out.
i had a rotax with a steel primary clutch just like this one and if it got a fluff of snow on it the cluthes would start rolling smoke and eat the belt,try to find an aluminum primary clutch and the cool faster for better belt grip
Got the same engine on a buggy frame
Sweet old power plant. The motor was rated for about 36 hp. Put the exhaust back on it before you run it, it could ruin the cylinders without back pressure.
Put it in the Nash! Cool
wondering why you have a battery connected? It doesnt need it to run.
95 is a bit low. 110 up or 130 is better !. Mate it up to a Subary 360 gearbox and fit it with chambers etc. Twin carbs. more torque. it'll fly
Now you just need a donor car body to slot it into : )
oh Iv'e got plenty
Micro car? WTF sell it to someone who restores old yamaka or snojet snowmachines.
Its a Yamaha GP 433 1973 engine at 38 hp normaly fan coled but they got GP/SR and GP/SS kit F/A to it but its not like the SR or SR facktory racing i got its a lot of diffrens it got a 185 psi in comretion wolfam plugged big ends special pistons 1 mm rings cromed cyl bor sandcast 6 bolt cylinder head twin pipes 50 mm kehin metanol carbs only the name Yamaha SR 433 is the same as a consumer engine facebook.com/erik.k.oberg.1/videos/10218097584251854/
these are not pulleys but clutch they cll it primery clutch and secondary clutch but nice engine and looks like its a good one to good scores bud
Ha..Ha..A pull start car with a get out and push for reverse!
Depending on what that engine's compression shouldli be I'd still say 100 lbs on a engine that has been sitting is pretty decent. I'd certainly say it ran well and started right up. Sounded like it will be a real strong runner. Maybe out of a 71 ThunderJet... I saw somewhere where cylinder code for that year and model was R
Nothing special here