primer bulb problem?

[Steve08753]

I have a 115hp carb 2 stroke Yamaha with a small problem. The motor starts fine when cold and runs great, but intermittantly after running a few miles and shutting off for a short time it will stall on the restart and then not run, when this happens the bulb will be soft, I then pump the bulb, push the throttle foward in neutral and restart using the choke. When this has happened it has only been at the first shut down of the day, after that it's fine all day long, I have a new fuel pump and the tank vent is clear, I was thinking the check valve in the primer could be sticking allowing the fuel to siphon back to the tank, does this seem reasonable?

 

[Ray Neudecker]

Re: primer bulb problem?

Best solution is to replace the hose assembly with factory installed bulb. The cheap route is to go buy a bulb and clamp it in. May be expensive in the long run. I have seen a lot of failures from this approach on larger engines.