carb question

[stewdog09]

87 mercruiser 454 with 4bbl carb

i was running my boat today and i saw there is a clear rubber hose at the front middle bottom of the carb going down next to the starboard side of the engine. Is this is a fuel overflow and if so where does it lead? back into the tank?. thanks

 

[Don S]

Re: carb question

It's only purpose is if the fuel pump diaphragm fails, the fuel that would leak externally in automotive pumps, will now go up that hose and into the carb causing running problems instead of into the bilge causing explosions and fires.

 

[stewdog09]

Re: carb question

could this be why i can only get 3k rpms out of my motor, if i push the throttle anywhere past that it bogs out completely. thank you for your quick reply.

 

[thumpar]

Re: carb question

If the clear line has fuel in it you need a new fuel pump.

 

[Don S]

Re: carb question

could this be why i can only get 3k rpms out of my motor, if i push the throttle anywhere past that it bogs out completely. thank you for your quick reply.

Does the line have fuel flowing through it when it's running?

 

[stewdog09]

Re: carb question

Yes it's moving through it at a decent speed

 

[stewdog09]

Re: carb question

although i had the fuel pump hooked up to a 10 gallon auxillary plastic tank, could this have anything to do with it

 

[thumpar]

Re: carb question

although i had the fuel pump hooked up to a 10 gallon auxillary plastic tank, could this have anything to do with it

No. When the fuel pump diaphragm breaks it pumps the excess fuel into the carb so that it doesn't just drain into the boat as a fire hazard. You need a fuel pump.

 

[stewdog09]

Re: carb question

okay thanks alot guys