Carb problem, please help

[roscottjr]

Ok, I narrowed the issue doen to 1 of the carbs. After disconnecting the plug wires one by one and checking spark as well I found the bottome cylinder was getting no fuel. I have cleaned the carbs on this engine 5 times now so I know without a dought both carbs are getting fuel. In hopes that maybe the bottom carb was bad I switched the carbs and just as I expected now the top cylinder is not getting fuel so I know without a dought it is the carb. When I cover the front of the carb with my hand it will pull gas in and run fine but only if the front of the carb is completely covered. The boat sat for about 2 years so the first thing I did was clean the carbs and then rebuilt the one thats no working but to no avail.

I have cleaned every nook, cranny, passage, port, and every other part of the carb 5 times and still getting nothing from the carb to cylinder. The carb is getting fuel to the bowl but its like it dont want to let it pass to the cylinder. Due to the issue and the cleaning and carb rebuild not helping I purchased a new carb and will update when I receive it.

Anyone know what may be going on with this carb? Is it possible for a carb to just go bad and cant be fixed? I do all my own mechanical work on my vehicles and boats and also do auto mechanic as a side job but have never run into anything like this before. Usually after a rebuild they work fine but this one is being extremelly stubborn.

If anyone knows what the problem may be I would be extremelly thankful for the info.

Thanks
Robert

 

[F_R]

Re: Carb problem, please help

Your qualifications and experience suggest that you are way too smart to have not checked the high speed jet orfice plug in the carburetor float bowl, right? It is right down there in the bottom of the bowl where the last few drops of gas lie and turn to gum.

Your qualifications and experience also suggest that you put a new gasket on the pipe in the center of the float bowl, around the main nozzle, right?

Carburetors don't just go bad. They just get dirty or gummed up. Or screwed up.

 

[tashasdaddy]

Re: Carb problem, please help

"Carburetors don't just go bad. They just get dirty or gummed up. Or screwed up." ain't that the truth.

 

[Silvertip]

Re: Carb problem, please help

You checked compression on the bad cylinder didn't you?. A piston with a hole in it will not develop compression nor will it develop crankcase vacuum which is required in a two stroke.

 

[roscottjr]

Re: Carb problem, please help

F R

yes to all. The carb received a complete rebuild kit as well as complete cleaning which also involved soaking overnight to loosen anything clogged. Also, used needles and wire to chase all the passages to be sure they were all clear.




Silvertip, I know without a dought it is not a compression or piston issue. I switched the carbs and the issue also switched therfore proveing without a dought it was the carb.

 

[roscottjr]

Re: Carb problem, please help

Also, when the engine is running it has the same "suction" on the bad carb as it does on the good carb. Only when I completely cover the bad carb preventing the suction it then gets fuel to the cylinder.

 

[tashasdaddy]

Re: Carb problem, please help

please read. http://forums.iboats.com/showthread.php?t=250879
what motor are you working on????????

 

[roscottjr]

Re: Carb problem, please help

1993 Johnson 48hp

 

[roscottjr]

Re: Carb problem, please help

read that already, also searched already.

 

[roscottjr]

Re: Carb problem, please help

New carb came in today and engine is now running great.

Thanks for all the help.

Robert