Is it a fuel pump or a fuel petcock in a gravity feed? On my little honda scooter, there's a vacuum line that runs to a petcock, so when there's intake manifold vacuum, it lets the fuel flow. I don't know if it's the same deal for you, but maybe it is.

By Darrell--Arizona-- (68.109.151.121) on Thursday, April 07, 2005 - 05:49 pm:

Most carbs have an overflow hole or tube as well. So that's probable gummed up too.

The float touches valve and turns it off. If you take apart the carb, you'll probably see lots of old gas. Its usually white and crusty and maybe like a jel.

I used to test the valve by blowing air (with my mouth) into the inlet hose and manually operating the float. You should hear the air stopping and starting as you move the float.

Almost every part can be taken apart and cleaned. Or you can just by the rebuild kit.

By jeff (149.99.114.88) on Thursday, April 07, 2005 - 05:14 pm:

Rotax is from Austria

By Zippy (Zippy) (12.106.14.107) on Thursday, April 07, 2005 - 12:06 pm:

Floats?
That's a great idea.
Rebuild kits are on the way.
For some reason I thought that 2-stroke carbs didn't have floats. I probably heard that from somebody that had no idea what they were talking about.
Thanks. I'll let you know if it dosen't work.

By Chaffneue (Chaffneue) (66.183.190.188) on Thursday, April 07, 2005 - 08:14 am:

yep probably the float or float needle...

-Richard

By Jacob (65.113.241.30) on Thursday, April 07, 2005 - 08:04 am:

It sounds to me like the float in the bowls are set incorrectly and continually let fuel through the carb. Not an expert myself on small motors, but I've had a lot of them apart. My vote is for incorrectly set floats.

By Zippy (Zippy) (12.106.14.107) on Thursday, April 07, 2005 - 07:29 am:

I know this is off topic but please indulge me. Ya'll are the best resource I know.

My friend just bought a snowmobile from the mid ‘80’s. It’s in good shape except for one item. It has a Rotax brand 2-stroke engine. Dual carbs, dual exhaust, really hot motor. Rotax is Australian. Anyway, the fuel is flowing way too freely from the tank through the carbs, it appears that it fills the crank case, and actually runs out of the exhaust. The fuel spilled all over the back of my truck in transport and flowed all across Brad’s garage floor. Brad took the fuel pump(?) apart and nothing was obviously broken. What is supposed to regulate the fuel flow through this thing. When it runs it is running rich. I have mapped the fuel lines and found it to be much more complex than anything I’m used to. Numerous lines have no purpose that I could easily discern. Could the fuel pump(?) be a mechanical item powered by the crank case vacuum? Brad told me (and I could not see any) that there were no electrical lines going to this unit. Just four lines, 1 gas to each carb, 1 gas to the tank, and 1 to the crank case. Anyway, I’m lost. I don’t know 2-strokes and Brad is kind of depending on me to provide the knowledge to fix this for him. When it runs I’ll get to ride his other sled. What controls fuel flow and why is it letting the fuel spill everywhere.

Any answers or resources would be appreciated. Email address should be linked to my name above.