1987 40hp Evinrude Mystery Hose ID

Bob36

Recruit
Joined
Jul 9, 2011
Messages
3
I recently bought a pontoon with a 1987 40 hp Evinrude. It isn't running well - seems to be running lean. I removed the air intake shroud and discovered a hose connected to a nipple at the very bottom of the intake manifold. The other end of the hose is connected to nothing. I put the end of the hose in a cup of fuel and turned the flywheel by hand and the hose blows bubbles or sucks fuel depending where the piston stroke is. I don't see anywhere this hose should be connected.

Any ideas what its purpose is? I'm sure it is the cause of the lean run.
 

AEROCOOK

Master Chief Petty Officer
Joined
Jul 28, 2004
Messages
872
Re: 1987 40hp Evinrude Mystery Hose ID

I believe it should attach somewhere along the bottom of the air silencer. It's purpose as far as I know is to draw in any fuel that may have drained out of the carbs while the motor was tilted up.
My 110 Johnson has a similar hose. I doubt its causing a lean condition because whether it's properly attached to the silencer or not, it's still open at the end.
When were the carbs last cleaned?
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: 1987 40hp Evinrude Mystery Hose ID

Agreed, I think you are looking at a drain hose from the silencer. EPA says you can't leak fuel, so they pipe it into the engine for burning. Has absolutely nothing to do with your lean condition.
 

Bob36

Recruit
Joined
Jul 9, 2011
Messages
3
Re: 1987 40hp Evinrude Mystery Hose ID

OK on the silencer line but there is no provision I can see for the tube to connect to the silencer housing. ?

I have the past service records from the PO. There is a work order two years old for carb rebuilding. The VRO has been bypassed and I believe the oil intake tube is disconnected but the oil nipple on the VRO is not plugged - may be the cause of the lean condition.

Did a compression check ~165# on both cylinders. Starts right up, idles poorly, sneezes, runs worse, and then stalls.

Thanks for the help.
 
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