Stalling 1965 Merc 39

Outboard Related Only
Posts: 1034
Joined: Tue Mar 10, 2015 11:39 pm
Location: Montreal Canada

Re: Stalling 1965 Merc 39

Postby crosbyman » Sun Jun 10, 2018 7:37 am

mine doing the same thing till I raised up the fuel tank and put it on the back seat next to the engine and it stopped dying

that's how I used it after but never dug in and get around to check out the fuel pump....I moved on to a 9.5 as my troller and back up engine.

I suspect the pump was weak somehow and could not lift the gas so I am likely due to change the diaphragm

also... do check for air leaks in that silly little connector and ensure the tank vent is clean


david bartlett
Posts: 1335
Joined: Tue Mar 10, 2015 10:15 pm
Location: Western Maine

Re: Stalling 1965 Merc 39

Postby david bartlett » Sun Jun 10, 2018 7:42 pm

I had a 9.8hp of the same vintage that would do the same thing. One of the check valves in the fuel pump was stuck, so it would not pump well, and these pumps are small to start with. Ran great with the tank up high. Unsticking the check valve fixed my issue.
AOMCI Member
Member Pine Tree Boating Club chapter of AOMCI

"I don't fully understand everything I know."
"There is nothing — absolutely nothing — half so much worth doing as simply messing about in boats." (Kenneth Grahame)

Dave Bernard
Posts: 754
Joined: Wed Mar 11, 2015 12:00 pm

Re: Stalling 1965 Merc 39

Postby Dave Bernard » Sun Jun 10, 2018 8:26 pm

convert to the latter larger pump like merc recommended back then. problem full fix.

Posts: 51
Joined: Sat Apr 18, 2015 11:06 am

Re: Stalling 1965 Merc 39

Postby Enrico-Italy » Tue Jun 12, 2018 1:30 pm

I had the same problem on a 1970 Merc 40.

After 20 mins or so, the motor stalls... often it don't stop completely, but it runs "rougly" as flooding.

Checked many times the carb and fuel pump, I finally find the problem was the under flywheel coil... or, better, the cable connection into the coil.

Return to “Ask A Member”

Who is online

Users browsing this forum: XR55 and 7 guests