1988 Mariner 135 Hard Start/Poor Running

[Jeremyastro]

I have a 1988 Mariner 135. When I put it in the water I have a hard time getting it to start. It will hit but not crank. After it hits several times it will crank and idle rough. Once you got into the throttle it bogs real bad. At full throttle it want plane out. It will putt a couple times and opens up and runs great the rest of the day. I rebuilt my fuel pump and cleaned the carbs but can’t figure out what’s wrong. I put new plugs in today and it’s still not right. Thanks if anyone can help

 

[GA_Boater]

Jeremyastro

Here is your own thread.

 

[Chris1956]

Sounds like the motor is out of tune. I would make sure the choke is working, and then check the idle pickup and max spark advance, to make sure the carbs and spark are synched.

Check condition of spark plugs and check wires for spark arcing. Did you check for spark on all 6 cylinders? Did you check compression?