Fuel in oil???

[Darol Wester]

I have a 1997 9.9 4 stroke Yamaha for trolling. It's been an excellent motor but, this year I found gas in the crankcase. What's the problem and how can I correct it? I'd appreciate any help you could pass my way. Thanks. Darol <br /><br />#"s on motor= T99EXHW<br /> X 788521

 

[rodbolt]

Re: Fuel in oil???

w is a 98 model but its close. the normal cause is its running to cool and not at enough rpm. you may also try a good decarb, check the fuelpump diaphram and make sure the carb is not flooding.

 

[Darol Wester]

Re: Fuel in oil???

This motors main function is to push a 6000lb. fishing boat all day trolling for Salmon. (Sport fishing) It has the big prop and the gear reduction on it. Would it be running cool with the job that it has? We've been using the motor now for about seven years and no troubles till now. There was enough fuel in the crankcase that it reads at the top of the dipstick.

 

[rodbolt]

Re: Fuel in oil???

when was the last time the fuel pump was checked as a maint item, when was the last time the routine maint check on the t-stat was done?

 

[Darol Wester]

Re: Fuel in oil???

To be honest, it didn't get any attention this spring other than plugs and new oil in the lower unit. It will be first on my list. Thanks. I appreciate your help. Darol