540CC Yamaha Motor in a dune Buggy

[copter6]

This is a little project I built in High School. It has been in Storage for the past 4 years. I have a few questions for anyone who can help.

1) Can I put any tach from a sled on this motor or does it need a specific one?

2) Would anybody have a jetting chart or know where I could get one for an 88?? Yamaha 540?

3) Currently as it sits when I hit the gas the clutch burns the belt pretty bad should I just throw some weight at it or less weight in the clutch? I don't know very much about clutching!

If I can get this running decent it should be a pretty fun little toy! Here are some pictures for everyone to enjoy!

 

[Transporter]

Nice job, had a srv with the 540 but never jetted it just rode it.

 

[89sandman]

sweet, maybe a big bore kit next

 

[0007]

What's the final drive ratio?
Need a calculator to figure it out but I would think you would need about 4 to 1 reduction

As far as a tach goes, the easiest and cheepest would be a chainsaw tach, you can get it from any saw shop and install it in minutes
Engagement should be about 4500rpm
Call the oldest yamaha dealer you can find and ask for sea level jetting for the year of sled you have
I see a 4 stroke muffler on there, that's not a good idea, what does the rest of the exhaust look like?

 

[Givemeaboost]

What's the final drive ratio?
Need a calculator to figure it out but I would think you would need about 4 to 1 reduction

As far as a tach goes, the easiest and cheepest would be a chainsaw tach, you can get it from any saw shop and install it in minutes
Engagement should be about 4500rpm
Call the oldest yamaha dealer you can find and ask for sea level jetting for the year of sled you have
I see a 4 stroke muffler on there, that's not a good idea, what does the rest of the exhaust look like?

There doesn't seem to be an expansion chamber on the exhaust(unless it's hidden underneath) so the engine will never produce enough power to move that machine.

 

[diirtbag]

check out and post your questions on minibuggy.net they specialize in this stuff,sweet build almost done

 

[BeeDoo]

I would also worry about overheating. Snowmobile engines run well when it's cold, but esp. those old engines really have issues in warmer weather.

I also had an SRV at one time. I'm assuming this is a fan-cooled engine? My SRV sucked when it was 35 or warmer.

Good luck though, it's a cool project!

 

[copter6]

I never thought not having an expansion chamber would hurt the performance that bad. I just figured it would decrease the longevity of the motor and also hurt the HP a little bit. I know that the Fan cooled motor will get hot but it is what we had at the time. I will have to fab up the original pipe and put on some sort of can to quit this thing down a little bit. I just hope I can get it running decent!

I think I will start with getting the pipe and can fabbed up then work on some of the other areas.

 

[Givemeaboost]

A two stroke needs an expansion chamber to keep the fuel from all blowing out the exhaust. They will run but not build any power.

 

[Flakey]

I've always wanted to build a mini rail like that. Only with a 1000cc sportbike motor. Ahhh..... that would be sweet.....




Nice build!

 

[metallicat]

Jeff, Corey here, Yamaha guru would be terry moe at T's Team Yamaha in Bottineau. He's been around Yami's forever. If he doesn't know for sure, he will fill you so full of s**t, you'll at least think he knows what he's talking about! probably see you saturday.