Fuel Issue?

seanny77

Recruit
Joined
Jul 15, 2012
Messages
3
Hi Guys,

Just wondering if anyone could provide any insight into this issue. I have a 1984 johnson 9.9. It runs fine for about a minute or so then it starts to lose power. After a few minutes it won't run at full throttle and instead the engine will just starve and die. If i pull the choke out all the way it will run at full throttle but only at around 80% speed. After running it like this for approximately 20 minutes it almost entirely dies and at full throttle i'll only be going 2-3 km per hour.

The bulb is pumped and hard.

The carb has been cleaned. I could see the carb cleaner coming out of the jet. Even with the carb off I seen no varnished gas in the bowl. Carb looked like it was rebuilt not too long ago (fresh float)

The fuel pump is only a few years old (was replaced previous to this issue - well before the issue started)

The gas tank is vented.

It's fresh gas - no water in it.

Also ran some sea foam in the tank just for the heck of it.

When it starts to die i will pump the bulb but it's still firm and has no effect on the engine.

Could it be anything other than the fuel pump at this point?

Thanks,

Sean
 

seanny77

Recruit
Joined
Jul 15, 2012
Messages
3
Re: Fuel Issue?

oh and ....After a few hours of letting it sit it will run normal again for a minute and then this entire cycle again.
 

Rick.

Captain
Joined
Jul 30, 2006
Messages
3,740
Re: Fuel Issue?

Check your compression. It sounds as though your engine is not drawing fuel from the carb. Did you remove the carb., tear it down and clean every passage and then blow it out from both directions with compressed air? Did you set you slow speed needle out 1 1/2 turns out from gently seated. Your symptoms are that of a dirty carb. Let us know. Best of luck. Rick.
 

seanny77

Recruit
Joined
Jul 15, 2012
Messages
3
Re: Fuel Issue?

Thanks for replying Rick. It seemed like a dirty carb to me as well that's why I ripped it off and went to give it a thorough cleaning but when I took the bowl off there was no varnished gas or any signs of varnish anywhere. So I basically just sprayed the fuel inlet etc with carb cleaner...ensured it was coming out of the jets etc and put it back in the outboard. I'll give it a thorough clearning this time but if it was the carb wouldn't it be more consistent performance.....meaning wouldn't it run like crap all the time as opposed to periodically? Keep in mind if I let it sit a few hours it's back to normal for a few minutes then it happens all over again.
 
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