I posted this before, but still cant figure it out.

My buddy has a 450, and the carb use to leak fuel. Once he went to start it up it ran fine, got warm and shut off. Then went to start it again it wouldn't.. Waited for a while then it stated again, but did not run good. Then never ran again.

We thought it was the carb, cleaned it up, but still wont start. Does the motor suck the fuel from the carb, or does the carb shoot the fuel into the motor?
We put a little gas down the plug hole, and it started that way, but still did not run after the fuel from what we dumped down the plug hole was gone. Fuel lines are clean.

We heard, maybe low compression, bad valves, bad crank, bad piston, stator going out. But these dont seem right. I dont know. Any suggestions.

Good spark, and new plug.
Stock motor. Stock exhaust. KN airfilter no lid.

 

Where was the carb leaking fuel from? The overflow tube?

 

There are many carb's that run off a vaccum pressure to flow fuel, try double checking these lines/hoses making sure the are hooked up and in the correct location. keep us informed.

 

Yes the fuel is comming out of the overflow tube. It is closed, all lines are clear.

Going to run a compression test on the bike. To do this the airfilter needs to be off, and the carb wide open right? Crank about 6 times also.

Does anybody know what the stock compression should be? 180 lbs??

Thanks

 

Maybe the floats are sticking closed. Maybe the jets are pluged up. Check to see if the slide is moving in the carb.

 

we did that. About the only thing we can think of is that there is not enough suction from motor to pull gas into the motor.

Valves? Rings?

Funny thing is when the bike was parked, it ran fine, then went to start it up a few weeks later. It would not run. Ran for a while, very choppy, then shut off. Never started again. Unless we put gas down the plug hole. THen it started.

 

If it was the valves it would not run with the pouring the gas in the cylinder due to the lack of compression. That is what I think. Is the plug wet when you turn over a couple of times?

 

Well you said that it ran fine before you parked it and you said that the carb was leaking so that makes me believe that the carb has problems like clogged jets stuck float or something got gummed up... check the diaphragm because it can cause huge problems for you if it is torn or isn't seated right...you also had mentioned that you have a K&N and no airbox lid...Did you rejet the carb so that you aren't running lean as your air fuell mixture will have changed greatly from these mods.

 

Check your petcock, lol[img]i/expressions/face-icon-small-smile.gif[/img]

 

We went through the jets, put different ones in for the air box and K&N. Guess last thing to do is, take the carb completly apart guts and all. Replace all seal and bushings, and what ever. Maybe just get another carb if the labor and parts add up just as much.

The cab is getting gas. Drained it from the bowl. Just from the bowl to the motor its not working. Plug was not getting wet either.

Thanks for the help, my friend will have to get the carb checked out.. Much cheaper then ripping the motor apart and finding out it was the carb. lol.