Has a fresh top end. Carburetor cleaned. Fresh fuel mix. Reed valve looks ok. Air filter and intake, ok. Has good spark. After it dies, the plug is wet.

Restarts after cleaning plug?

I checked the stop switch and harness. I inspected wiring and connectors, ignition coil primary and secondary circuits. Checked for intake air leaks. Runs great than just dies and fuel fouls the plug.

Could a malfunctioning or maladjusted power valve be causing this?

How do I check and adjust them?

Also, could it be the carburetor power jet solenoid?

How do I test it?

  • It sounds like you don't need the choke to start the bike. Please confirm
    – Zaid
    Mar 27, 2016 at 2:20
  • Also, what work was done to the carb? Was it rejetted by any chance?
    – Zaid
    Mar 27, 2016 at 2:29
  • I doubt it would be the power valve. Have you checked to see if the carb is flooding? Perhaps a stuck float or something along that line that's allowing fuel to get into the bottom end...you try and start it with a bunch of fuel in the crankcase it begins to get hot and then fouls the plug....something along that line maybe? Mar 27, 2016 at 5:36

2 Answers 2


Here's a theory

Too much fuel built up in the crankcase.

Could be from a petcock leaking and a stuck float.

Here's the theory

Too much fuel in the crankcase.

You start the bike.

It begins to heat up while your blipping the throttle

Engine cases begin to get hot.

Fuel thins up with the heat.

You start riding and crank spins up and begins to throw the excess fuel around in the crankcase.

Mixture get's too rich and your bike dies.

You pull the plug and see that it's wet.

Solutions and things to check

  • Petcock - is it leaking?

  • Needle and Seat - is the float sticking open and allowing fuel to drip into the crankcase?

  • Drain the crankcase - Was there a bunch of fuel in there?

Hope it's as simple as a stuck float. Good luck.


It sounds like the issue here is with air-fuel metering. A wet plug means unburnt fuel, so you either have too much fuel or not enough air making its way into the cylinder.

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