Logo
FULL SITE MENU

Mercury 40hp oil injection

W

Wisedom84

New member
Hi, I just bought this engine, compression is good on all 4 cylinders, the boat is really hard to start and it will only start with fast iddle lever up right or with a lot of throttle apply. Once started i can't have it at iddle with the fast iddle lever upright otherwise it stall. As for power, i have 14.5 ft bass boat and at wide open throttle I can get up to 6.2 miles per hours. If I am at low speed and go wideopen throttle there is a lag and it seem like it wants to stall but it does not stall. There seem to be oil/gas on top of the bottom carb. And it burn 3 gallons of gas for 3 hours of trollingat low speed and I was wondering if it's normal consomption.


Can anyone tell me what to look for since I live far from any mechanic.
I have good basic engine knowledge but i dont want to start tearing it appart if i don't have too.
Spark plug are good.
Thank you very much
 
Try a cylinder drop test on her, pulling one plug wire at a time with plastic pliers. Does the primer bulb firm up prior to startup? Have u tried pumping manual pump while running"primer bulb?
 
The pump can't seem to get really hard, it's not soft to the touch but i can always squeeze it. By doing the cylinder drop what should i expect and what would be a bad result.
 
When you pull a plug wire off the motor sound should change ( slow down )----When you put the wire back on the motor should speed up again.----No change indicates a problem.
 
Back
Top