stuck carb?

[tcastle]

I have a 1996 9.9 Mercury 4 stroke kicker motor. When I transfer it to the lake it won't start. When I bring it into the shop they take the carb apart than run the motor and everything is fine, until I go to the lake with it, than it won't start. It will run for 1 half second than die, after that nothing until the shop gets it going. They even put a brand new carb on and I thought everything was ok but aparently not. What is sticking? How do I fix this? My mechanic isn't getting it done. What can I do to diagnose this headache? Primer bulb is always hard and if I spray carb cleaner in carb, motor will start but not run without spraying cleaner in carb to keep running

 

[rickdb1boat]

Re: stuck carb?

If the float needle is sticking closed, that would cause your problem. Try lightly tapping on the float bowl with a screwdriver handle when this happens and see if it does any better. This may free up the float needle, if stuck. But that should not be happening on a new carb. Was this the original problem with it? I would be inclined to take it back to the shop and have them find out what the real problem is, since that's what you paid them for.. Are they running it on Muffs or in a tank when they perform the tests? Could be a backpressure problem, too.

 

[tcastle]

Re: stuck carb?

If the float needle was sticking closed wouldn't it run a little bit before it ran out of gas and died for good? What do you mean "it could be a back pressure problem?" The problem I am haveing now was my original problem when they replaced the carb. Something is sticking when I travel with it but I don't know what. Besides the float needle is there another needle that can cause problems like this? It is very frustrating and has been going on for over a year now.

 

[randycc58]

Re: stuck carb?

if the float needle is sticking in the carb it will not let gas through to the engine for combustion. if it will run with starting fluid , it suggest that it isn't getting fuel. back pressure problem is when you have the engine in water, it puts pressure on the engine exhaust to escape. a engine may crank fine with the ear muffs, but not when its in the water. a common problem could be a cable adjustment on the throttle side. think of a clutch on your truck. if you dont give a little extra gas when you put it in gear, it will shut off. your throttle cable advances a little ahead of the shift cable so you will have the little extra gas to keep it going. a engine requires more fuel under load (back pressure) its a simple problem. but I do agree with taking it back to who sold you the new carb. they should have tank tested it before sending you out in it. soundds to me like you might need a new tech.

 

[eurolarva]

Re: stuck carb?

Have them do a compression test on while they have it.