Yamaha 9.9 won't rev 1-2 min after starting

croper

Recruit
Joined
Jul 30, 2009
Messages
1
I have a 1996 Yamaha 9.9 high thrust 4 stroke kicker that starts perfectly and will idle and rev for first 1-2 min then will only idle rough and when I hit the throttle it misses badly and won't run. It never actually stalls out but somehow gas is not getting to the spark. I checked the carb jets, used ignition chamber cleaner and checked thr fuel pump. I think maybe the float is stuck? Somehow fuel is running out after 1-2 min. Help please. Chris.
 

n6rfm

Cadet
Joined
Aug 24, 2008
Messages
15
Re: Yamaha 9.9 won't rev 1-2 min after starting

Obstruction or air leak in fuel line upstream of fuel pump (e.g, bad filter)? Does the bulb hold pressure after pumping for a while before starting? What happens if you pump the fuel line bulb a few times after the first minute or so after starting?

If you checked the jets, did the float and needle look/work OK? Were the needle and seat spray cleaned as well? Inside the carb, there is another filter at the bottom of the bowl. Inspected, carefully cleaned?

Perhaps this is not fuel related but engine temperature associated? How do plugs look when engine quits? Any sign of water in oil?
 
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