2002 9.9 Merc - Fuel blowing out of the top.

Merc 9.9, 4 stroke 2002 Ser#OT544718
Here is what happens. After a few days of sitting, I prime the bulb slightly, choke, pull and bang, starts right up. At this point fuel begins to dump out of the TOP of the carb, I work the throttle and finally after a few seconds it dies and so much fuel has blown out of the top of the carb that there is a puddle in the bottem of the engine housing.
Also if I over prime the fuel bulb does not harden, instead fuel pumps out of the top of the carb and out of the air intake.
I did a search for this problem and found possible stuck float, but the thread never resolved the problem. Any ideas?

Re: 2002 9.9 Merc - Fuel blowing out of the top.

I don't know squat about this motor...but when fuel is coming out the top of your bowl....your needle isn't sealing off the fuel flow.

Re: 2002 9.9 Merc - Fuel blowing out of the top.

Now if I only knew what part is not working. Any thoughts? Here is my carb: Mercury, Mercruiser, Force, etc. - Carburetor - 8/9.9 (209CC) 4-STROKE

Re: 2002 9.9 Merc - Fuel blowing out of the top.

Brian;

Your engine is a 323cc engine, this carb is for a 209cc.

See my last entry on your other post:

http://forums.iboats.com/mercury-mariner-outboards/mercury-9-9-carb-question-590164.html

Gerry

Re: 2002 9.9 Merc - Fuel blowing out of the top.

Carholme,
Thanks, I believe the previous owner must have changed the carb. At the top of my carb is a canal that leads to the side of the carb as shown in the 209 model. The 323 does not show this canal, its actualy solid where mine has an opening, and that is why I think he changed it for the wrong model carb. If this is the wrong carb for my motor, would it cause the overflow out of this canal on the top of the carb? Here is a link to a carb that is a replicat to mine: Mercury Carburetor 1392 8846A14 Fits 9 9 | eBay The first pic that comes up shows the canal that I am refering to, it's on the top left of the carb. The last pic shows the side that is the main depiction in the parts scetches.

Re: 2002 9.9 Merc - Fuel blowing out of the top.

Mystery solved!
The float was stuck- that caused the needle valve to remain open. Once the carb was full it had nowhere to go but out of the relief canal. I took the thing apart and cleaned the axel that the float is attached to and reassembled. RUNS LIKE A DREAM!!!!!!!!! One other note, when I was in the carb I looked all lines from the accelerator pump. The accelerator assembly is NOT REQUIRED, no lines have any way of getting fuel to this area, they are all sealed integral to the carb No screws or plugs, they are solid metal. Must have been for a different model of motor that required this.

Re: 2002 9.9 Merc - Fuel blowing out of the top.

Look again, they are there.

The 4 stroke carb uses the accelerator pump to richen the mixture during throttle opeing, once the throttle is open then the main jet controls fuel flow.

But the accelerator pump is a necessary part.

Re: 2002 9.9 Merc - Fuel blowing out of the top.

It is unfortunate that you have scattered your questions over 2/3 different posts when it would be helpful if everything pertaining to your problem was contained in one post.

Based on the information you have provided, I still think that whoever changed the carb has installed the wrong carb. The one you quote is not listed for your s/n as we have already discussed. And you say that you have one on your engine which is for a 9.9 (209cc) when your engine is a 323cc.

And again for the 323cc engine those parts are not required, they are only for the 13.5 and 15hp engines as you see in the parts list. So, I have no idea where you are at, what carb p/n you have on your engine, except that you say it is running now.

Gerry

Re: 2002 9.9 Merc - Fuel blowing out of the top.

Thanks Gerry, the motor is running good. Now my concern is that I have the wrong carb on it. Is it safe to run the motor with the incorrect carb? Any suggestions as to what my next step should be?

Here is the only number on the carb: 66L50 8F7

Re: 2002 9.9 Merc - Fuel blowing out of the top.

Usually the major difference in carbs is the size of the throttle bore.

You need to measure yours, then find out the bore size of the correct cars, depending on how much difference there is I would be too concerned as you stated it runs like a dream.

IF your carb is a smaller bore than the correct carb all it will do is limit WOT power a bit but give excellent idle and part throttle response due to the higher air velocity and better fuel atomization, better combustion.

Not much of a problem and will do NO engine damage.

Does your boat have a tach?

What is your WOT RPM?

Will the motor get the boat on plane quickly or does it struggle?