90 horse outboard running bad.

[darin99]

I have a 1990 90 horse mercury outboard. The motor just doesn't seem too be up to power. When I start it cold it just acts like it doesn't even want to run. I ran a compression check on it, and was right at 120 on all 3 cylinders.

I decided to take a picture of the 3 spark plugs right after I pulled them out too see if anybody might know what the deal is. The top cylinder and bottom cylinder plugs always come out with what looks like just a tad bit of black fuel on them, while the middle cylinder plug every time I pull it out, is completely black with soot.

Does this look like I'm not getting fire on the cylinders possibly? Thanks

 

[jerryjerry05]

Re: 90 horse outboard running bad.

The second cylinder I believe is the cylinder that powers the fuel pump.
The diaphram in the pump could be bad.Take it apart and check for damage and strech.
Ethanol is a problem.
That not the problem,set the air screws.Clean the carbs,check the reeds.
Do a spark check. They sell a gap tester at most Auto Zones or whatever store is in your area. About $6 The gap should be 7/16" All three the same color.J