Fuel/Carb Problems on 1998 yamaha 9.9 two stroke outboard

reggiebad

Cadet
Joined
Nov 2, 2011
Messages
17
The motor starts easy and runs but once you push the choke back in it runs a few seconds and then dies. Its definately being starved of fuel but i am not sure if it is just plugged up or if there is a more complicated problem in the works. Its a 1998 Yamaha 9.9 MLHV Serial number L455187W if anyone can help I would much appreciate it. Thank you
 

rosscopeeko

Seaman
Joined
Jul 24, 2006
Messages
57
Re: Fuel/Carb Problems on 1998 yamaha 9.9 two stroke outboard

I have a similar motor to yours, only it's a 15hp 2002 model. Start by cleaning your carb. It's not hard to do on these motors. Remove and disassemble neatly and in an organized fashion. All you'll need is a can of brake clean or a comparable solvent, and compressed air. I have a manual, but i think you could do it without it. After cleaning the carb i would check and clean your fuel filter, check and or replace your fuel pump diaphram, and then when you get it running right run a tank of good fuel at 50:1 mix with a decent amount of yamaha ring free through it.
 

reggiebad

Cadet
Joined
Nov 2, 2011
Messages
17
Re: Fuel/Carb Problems on 1998 yamaha 9.9 two stroke outboard

Ok I did all that today I haven't ran it yet though. Everything in the carb and filter looked to be ok. I noticed when I took the carb off today that there was no gasket between the carb and block and it looked like in the past someone had removed it and used silcone to put it back together so I think that may be contributing to my problem or might be the problem itself. Im no expert but I am pretty sure there is supposed to be a gasket there and I know silicone and gas dont mix well. Do you think that might cause the problem?
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
8,851
Re: Fuel/Carb Problems on 1998 yamaha 9.9 two stroke outboard

If it is sucking air into the motor where the gasket is missing it will cause a lean condition
 
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