1988 yamaha wr500

[t.martin]

I have a fuel delivery problem, but i am not sure what it is. How do you test to make sure the fuel pump is working properly? I took the return line off of the carb and turned the motor over and fuel came out pretty strong for about 3 seconds and then it slowed down to a trickle. Is that normal? Any help will be appreciated.

 

[t.martin]

Re: 1988 yamaha wr500

I forgot to ask what mikuni rebuild kit do i need if i rebuild the carb/fuel pump?

 

[ozarkjeep]

Re: 1988 yamaha wr500

remove the pump diaphragm cover from the carb, and make sure it has no holes or ruptures, and make sure the passage ways inside there are clean. next verify the line from your tank to pump is free of obstructions.

 

[t.martin]

Re: 1988 yamaha wr500

I took the carb apart and cleaned it but I still have the same problem. It will only idle for a little while then it dies. I can't figure out how this carb is supposed to work. The needle acts like it controls the gas to the return line. How does the gas get to the manifold? The reason I ask this is I took the return line off at the carb and started it, it ran for a while then died, but there was still gas coming out of the return port on the carb.

 

[RandyJ]

Re: 1988 yamaha wr500

The sbtforums.com site has a couple of very good videos on carbs. In one he explains the path of fuel thru the carb. It is well worth looking into.