86 Mercury 35hp help

[Darin-C]

My 86 35Hp Merc. does not seem to be running at full power. Any suggestions on what to check or look at?

last year I had the motor tuned after I got it, not sure what all they did. Hunted in it last winter and it ran good.

This spring I did a seafoam treatment on the motor.
replaced the water pump impellar and I cleaned and rebuilt the carb.
and I have replaced the plugs.

After all that it ran great all salmon season for me. I have put 40+ hours of trolling speeds on it since then.

this fall it does not seem to be able to get me up to the speeds I had this summer, it has dropped of 4-5 MPH at full throttle.

any suggestions? is there something else to do on this besides what I have done?

Thanks, Darin

 

[JUSTINTIME]

Re: 86 Mercury 35hp help

compression check
spark check

 

[bgbass.1]

Re: 86 Mercury 35hp help

If above comments ok could be carb. dirty got some bad gas with all that trolling it will load up.

 

[Laddies]

Re: 86 Mercury 35hp help

I think bgbass is on the right track sounds like a fuel problem

 

[Darin-C]

Re: 86 Mercury 35hp help

compression check
spark check

I Checked the top Cylinder and it was 150psi, have to get an adapter to check the bottom cylinder due to the cowling.

What should the difference be between the cylinders?

I will change out the gas.

What should I look for or how do I check the spark issue?

 

[CarolinaWhaler]

Re: 86 Mercury 35hp help

Make sure your plugs are gapped to the manufacturers requirements.