Won't stay running

[Crabcakes]

I have a 9.9hp Tohatsu that will run for a few minutes then die when I squeeze the primer ball to feed gas to the motor, it gets firm like it should. When the motor dies the primer seems to lose the firmness. I checked the tank filter and cleaned it, cleaned motor fuel filter but found no dirt in either one. I'm not sure if its a fuel line problem ( from tank) or in the motor itself. I replaced the plugs and up until last yr never had a bit of problem with this motor. I'm getting a good amount of smoke when engine is warming up. Improper fuel mixture maybe??

 

[Sea Rider]

Re: Won't stay running

Welcome to the forums,

How old is that horse, when engine ia about to die prime fuel bulb again, if engine restarts raising rpm it's a fuel pump bad diaphragm issue, could be deformed, dried out, leaking, etc, change all diaphragms for new ones.

Happy Boating

 

[pvanv]

Re: Won't stay running

What is your actual model?

You could have any number of problems, but fuel system is likely. Could be a sticky float needle, fuel pump issue (as Luis suggested), or even a leaky o-ring in the primer hose connector(s).

 

[Crabcakes]

Re: Won't stay running

It's a 1993 Tohatsu 9.9 DS only thing I noticed was when I disconnected the fuel hose at the motor it started easier and ran smoother til fuel ran out before it cut off... A friend of mine said when his primer ball went bad his motor acted similarly

 

[Sea Rider]

Re: Won't stay running

That's a 20 year oldie hose, proper time for a new one. Somtimes connector's o'rings dries, wears out and engine sucks air, giving aceleration misbehaviors at different throttle ranges or engine dying and needing to prime again.

This same issue drove me cracy for some days untill a brand hose was installed and trouble dissapeared by magic. Get a good Samaritan to lend you a used one in good working condition to test before buying a new one.

Happy Boating