1988 Yamaha 9.9HP F9.9SG Carburetor parts/issues

[jcwolf]

Hello, I'm trying to find parts for my carburetor from my outboard. I need the main nozzle, however, all the parts sellers say it's discontinued. I've also looked for the full carb assembly and it's also discontinued. What am I supposed to do? The motor starts with a syringe of fuel shot into the air intake...but the carb is in bad shape...has oxidation I've tried to clean...have soaked it in carb cleaner, blown it out with compressor, etc. but the main nozzle has some damage and should be replaced (yet I'm not convinced that's the only issue). Any knowledge about part numbers that are superseded by newer parts? other carbs that will work on this engine? this is a complicated auto choke start system that has B.V.S valves for air/fuel mixture when cold vs. hot...kinda a pain in the ass.

Any help very much appreciated!

 

[tpenfield]

:welcome: to iBoats . . .

Fear not . . .

Try eBay . . . I did a quick search and there does seem to be some carburetors that may be (should be) a close fit. Nothing comes up on the exact P/N, but if you search for model year and HP, you will get some. You can always message the seller for more clarification.

Is this a 4-stroke by any chance?

 

[boscoe99]

F9.9sg.

 

[jcwolf]

Hi, thanks for the welcome!

Yes it is a 4-stroke motor. It is very different from anything I’ve seen before. An autochoke function that operates via BVS valves to create positive or negative pressure to adjust startup.
I’ve scoured eBay and cant find any similar. The carb was used from 86-91 as far as I can tell.

I finally got it running after tearing down and rebuilding the carb again and replacing the fuel filter with the right one made for the motor. It starts on one pull and warms up at about 2000 RPM, then changes to idle that is okay but a little rough.

The real problem now is that when I give it gas it doesn’t transfer from startup to main jet and it lugs and crackles out the air intake.

I think it’s running lean but I may have other issues too.

time to check valve clearance? Other thoughts?

 

[Sea Rider]

Which carb parts asside from Main Nozzle will be needing ?

Happy Boating

 

[jcwolf]

Honestly— I’d love to get the whole carburetor replaced if I could find one. This one was super corroded and I’ve soaked it in carb cleaner but still has white residue all over. Hard to clean it out. The main nozzle is damaged (the small slotted part at the bottom where the set screw holds it in place is broken off on both sides. I’ve soaked, air compressor blades and need poked every hole tried to clean it out. Maybe the thing is working okay, but can’t give it throttle or it just lugs and chokes.

see pictures of what I had to work with.