hey guys it's been a LONGGGG time

I was out on the yfz when it died and whould not start again. I took the carb apart and cleaned it. started up great, runs like new (did cam mod, adjusted valves, etc) and was very happy. I then noticed the fuel flowing constantly out the float bowl drain screw/ overflow hose. The on that is at the bottom of the carb. WTF I also just rebuilt the 660's carbs and they are both draining gass too. HELP I have no idea wtf i did.

I was deperate to ride so i made a plug and rode for hours but i want to fix it for good.

 

The fuel constantly running would be because the float valve is getting stuck open. Usually, this is because the floats get hung up inside the bowl because they're not installed correctly, or because the seats on the valve are getting worn out and it's getting stuck or leaking.

I think the fact that the same thing is happening with the 660 is more than just a coincidence. My first thoughts are that maybe you're being too rough with the floats when you're cleaning them, end either bending, breaking, or otherwise knocking the floats and valves out of adjustment from being too rough with them. Or maybe just leaving something out or putting something in backwards when you re-assembled.

The floats are one of those things you have to handle like a very fragile egg, and just try to avoid touching them completely whenever possible, because aside from being either intact or broken, the floats also have an adjustment to change the height that the fuel will be allowed to rise to.

I personally never had to adjust that, but a service manual may be a very helpful thing for you right now. That should give you a step-by-step of the procedure, and also give you the tolerances to adjust them to, and everybody's favorite, pictures!

 

fixed all three carbs. thxs for the help

now the rapy won't stay running. Yfz runs great.

rapy would start and run like crap and then die and not want to start up again

[img]i/expressions/face-icon-small-confused.gif[/img]

 

has anyone had a problem with their yfz 450 like almost dying wen your going slow or just idling along in the bottom of any gear and you give it all the throttle , i trying to figure out if its a carb problem or its misfiring i just want my atv to have no hesitation at all