2001 Yamaha HT 9.9 4 stroke intermittant stalling

[p23brian]

The motor seems to have a fuel problem. From a cold start it fires right up after squeezing the primer bulb until it's firm. After about 3-5 minutes the motor just stalls suddenly. It does this regardless of RPM. High speed or slow speed it does the same thing. After squeezing the primer bulb again and hitting the starter it fires right back up again and runs fine for another 3-5 minutes. The fuel is fresh and the vent on the fuel tank is open. Any other ideas about how to troubleshoot this? Thanks!

 

[mjbrueck]

Re: 2001 Yamaha HT 9.9 4 stroke intermittant stalling

Have you tried continuing to squeeze the bulb while it's running? For a little 4-stroke, 3 to 5 minutes would be about how long it would take to run the gas out of the carb. It sounds like it could be a fuel pump problem.

 

[Grant S]

Re: 2001 Yamaha HT 9.9 4 stroke intermittant stalling

They have an oil pressure cutout which could be faulty (or you have low oil pressure). It's on the side of the block , take the wire off and see if she still stalls. Possibly a pink wire.

 

[p23brian]

Re: 2001 Yamaha HT 9.9 4 stroke intermittant stalling

I don't think it's an oil pressure problem or an electrical problem. I guess it could be, but the way it starts right up again after I prime the bulb leads me to suspect a fuel problem. Maybe rebuilding the fuel pump would be a good first step. Is there a kit available that includes all the replaceable fuel pump parts or do I need to get them all separately? Thanks for the suggestions!

 

[Grant S]

Re: 2001 Yamaha HT 9.9 4 stroke intermittant stalling

My one with faulty oil pressure had those symptoms, but I agree it seems more like fuel related.