Fuel leaking from carb

xxturbowesxx

Chief Petty Officer
Joined
Apr 20, 2008
Messages
491
I have a 1994 xr4 when I'm running shallow at idle with the motor trimmed pretty high fuel runs out the bottom of the cowling. I know if the motor is trimmed all the way up the fuel will run out but it seems like this shouldn't happen.

Also i should mention the boat has a running problem wont reach full speed and wont plane normally. The boat will run reasonably fast then slow down. I just bought the boat today and used this to work out what turned out to be a bargain.

Should i remove the nuts from the bowls and pump fuel out? Ive pulled the carbs off my 1990 mariner 150 and they are the same so I'm not afraid of a rebuild if i have to. I pulled the fuel filter off and it was deteriorated very badly and i think part of the element was sucked into the bowl of the carbs.
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: Fuel leaking from carb

Definitely time for a carb rebuild, pay particular attention to the needle/seat & float level.
 

xxturbowesxx

Chief Petty Officer
Joined
Apr 20, 2008
Messages
491
Re: Fuel leaking from carb

The weird thing is the guy i bought it showed me a receipt where he had the carbs rebuilt. :confused:
 

lowkee

Lieutenant Commander
Joined
Dec 13, 2008
Messages
1,890
Re: Fuel leaking from carb

It's really easy to mess up a carb rebuild. Sometimes a tiny particle in the needle valve area (usually dirt or gasket scraping) can prevent it from seating properly. Don't be afraid to check it out. There isn't much to a carb. Just take the top assembly off, remove the float, splray some compressed air around the needle valve and seat and reassemble.

A few extra steps will cover the other possibilities:

- Shake the float next to your ear.. if it makes noise, it has a leak and needs replacing.
- Set the float level. This will vary per engine make, but normally if you keep it horizontal at close (when the needle is seated) you are close enough. Too low on close and your engine will sputter from lack of fuel at WOT, too high and it'll flood and leak fuel (like it does now).

Don't worry if it's your first time. Just take your time, keep parts in some kind of logical order, so it goes back together the same as you took it apart and don't force anything.
 

xxturbowesxx

Chief Petty Officer
Joined
Apr 20, 2008
Messages
491
Re: Fuel leaking from carb

I took the cover off of the carb and started the motor and it is spitting fuel from the middle carb right barrel. Its coming from the jet in front of the throttle plate.
 

xxturbowesxx

Chief Petty Officer
Joined
Apr 20, 2008
Messages
491
Re: Fuel leaking from carb

I sprayed carb cleaner in the jet and pulled the carb drain plug and flushed the bowl and it doesnt leak anymore. I must have freed up the float. So i put it in the water and its runing fast and alot better but still has issues idleing and sometimes doesnt plane as fast as it should. So now im going to hook up a portable tank on it to eliminate bad gas because its behaving like my old boat did when it had bad gas... Ill keep you guys posted and thanks for your help.
 
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