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Df 9.9 - runs best on partial choke

D

DON MILLS

New member
Hi.
Here are the details
10 years old, barely run df 9.9 four stroke
Stored for several years, no history available.
Moved to a new place and laid down ( two weeks) on wrong side.
When tested on a boat it had white smoke from the exhaust, would not run without at least half choke.
Pulled plugs. Found their tips oily, pulled cord, no oil came from cylinders.
Replaced plugs, changed oil , cleaned carburator.
Tested again, and although better running, it still required about 1/4 choke, and when throttled it lost power, surged up again, lost power etc.
Recleaned the carburator...test three, nothing changed.

The one thing I'm uncertain about in the carb cleaning was the pilot jet. It was really small. I could see light through it, but it was difficult.

I did test it before removing oil. Thebdipstick indicated more than the max level of oil. Did I damage it?

Any suggestions I ( handy but not a mechanic) i can do to get it running well?

thanks.
 
Strip throughly and clean the carurettor using an ultrasonic bath and lots of carb cleaner, make sure all the juets are thoroughly cleaned (use fishing line if you dont have carb brushes) then re-try to start.
 
thanks for your reply. not sure purchasing a sonic bath system is possible for me. I can try cleaning again but I'd be surprised that fishing line will fit through the jet.
Are there any adjustments that can be done?
 
DON MILLS said:
thanks for your reply. not sure purchasing a sonic bath system is possible for me. I can try cleaning again but I'd be surprised that fishing line will fit through the jet.
Are there any adjustments that can be done?
Click to expand...
I would suggest not to even consider adjustments until you are 100% sure the carb is immaculately clean, take a piece of 18 gauge multi strand electrical cable, strip a little insulation back and separate out the strands then use them to clean the jets, if you don’t have an ultrasonic cleaner disassemble the carb as much as possible, use carb cleaner and nylon brushes to clean as much ad you can and make sure the passages are blown through with compressed air, why not post the carb to someone who can clean it ?
 
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