Force 9.9hp carburetor

[wicked loose]

I have a 96 Force/Gamefisher 9.9hp with a leaky carburetor. Fuel comes out of the hi speed tube vent on the top of the carb when primed from the gas tank and the engine runs very rich if I can get it started at all. I have found the same problem on quite a few other threads on this forum and the fix is usually the same. Replace the needle and or adjust the float.
I have cleaned, inspected and adjusted this Tillotson HO5B till I?m blue in the face. Two new needles. New fuel pump. All new gaskets. New primer bulb assembly. Had the reed box out, no pitting or corrosion there. If I invert the carb and let the weight of the float sit on the needle there is no fuel leakage and it will hold pressure until I lift the float. There are no pin holes in the float and it will sit over half out of the bowl of gas when not attached to the body. The float pin and hinge hole are smooth and working free. Float adjustment with float level, nose up, or nose down all have the same effect.
I am out of ideas.

Thanks in advance; Jerry

 

[bentle]

Re: Force 9.9hp carburetor

Sounds like you have covered everything I would have suggested.
One other does come to mind though.
Is the float full of fuel and causing it not to float?
I have a 97 15 hp gamefisher and what I have learned is its really
Easy to over prime the carb, so forcing the fuel out the only place it can go.
I over primmed, fuel would run out and hello blistering while trying to start it.
When you prime it up try to prime it less and without much force on the bulb.
As soon as the bulb feels full and firm then stop there and then try to start.
Should only take a few pumps on the primmer bulb.
If its running good and no fuel leaking then it should be ok.

 

[wicked loose]

Re: Force 9.9hp carburetor

The Float weighs in at 8 grams but I don?t have any specs to compare that to. It is very buoyant and floats high in the water.
Not only will fuel come out of the vent when primed, it will also come out for the few seconds I can get the engine to idle. If I bypass the neutral stop and coax it to run at ? throttle the leaking stops but the engine smokes very badly. ( I use the same 50:1 fuel in my Johnson 9.9 and it doesn?t smoke).
Is there anything I can attach to the float to increase the buoyancy to apply little more pressure to the needle? Changing the float level will make a difference in travel but not lift. I need a tighter seal some how.
Jerry

 

[bentle]

Re: Force 9.9hp carburetor

Have you adjusted the float yet?
Float should sit flush or level with bottom of carb housing.
This is the opening the bowl mounts to.

 

[wicked loose]

Re: Force 9.9hp carburetor

Yes. As stated in my original post, I have adjusted everything I know of on this carbuetor. I Came to this forum to see if I had missed something along the way. I am not a novice at internal combustion but I also know multiple set of eyes and ears are sometimes helpful.

Thanks to everyone that read and gave my problem some thought. If I do get this figured out I will share my findings with the board.

Jerry

 

[bentle]

Re: Force 9.9hp carburetor

I looked at a schematic for your carb and I noticed that on the needle it states "do not remove the inlet seat" now im guessing that if it was removed then carb is no good because there isn't a replacement inlet seat part.
Is there any chance the inlet seat the needle sits in at close is damaged or maybe a piece of crud stuck up in there and not allowing the needle to close.
I understand you have been through this carb in and out, but if the needle doesn't seat properly then there's some flooding.
Im sure you've been through it to the point of hair pulling but what the heck? It couldn't hurt to have another look.
If anything is available to make the float have more buoyancy other than some homemade handy work im not aware of it.
Good luck.


Bentle

 

[wicked loose]

Re: Force 9.9hp carburetor

Thanks, Bentle. There is a stainless inlet seat in this carb and I have inspected it closely with a 10 power loop. Also if I invert the carb with the fuel line hooked up the weight of the float alone will stop the fuel when I pump the tank primer. I just got this motor last fall when I bought the jon boat and It has run pretty bad since the beginning.

At this point, I am sitting at my camp with the river running by and the engine is sitting at home with the carb on my bench thinking about what it is doing to me. It has 4 days to think about it.

I appreciate the support.

Jerry

 

[duke33]

Re: Force 9.9hp carburetor

can you bend the tab that holds the needle up?....

 

[wicked loose]

Re: Force 9.9hp carburetor

Yes, thanks for your input. The metal tab adjustment is part of the float level sequence. Been there, done that.

 

[fishrdan]

Re: Force 9.9hp carburetor

It sounds like the needle/seat isn't sealing correctly, even if the needle has been changed, the replacement part could be bad, tip of the needle hard and not sealing off. If you pump the primer bulb, the carb's needle/seat should cut off fuel to the carb once the bowl is full. If you can hold slight pressure on the primer bulb and the carb continues to overflow, the needle/seat isn't sealing properly.

With the bowl off the carb, jerry rig the primer bulb to the carb fuel inlet, pump the primer bulb and see what happens when you have the float at the proper closed height and what happens if you have it a bit higher. How much pressure on the float does it take to stop the fuel flow?

I have the same style of carb on my 7.5 Force/Gamefisher and prime the carb by squeezing the primer bulb hard, until it's firm and I can't squeeze it any further. It doesn't overflow.

 

[Scrapmetalbuyer]

Where can I find carb rebuild kit and thermostat ?

 

[GA_Boater]

Where can I find carb rebuild kit and thermostat ?

You begin by starting a thread of your own with some information to ID your 9.9. Look at the Help Tip on top of the page.