[whatever4]

Have 1986 50 hp Evinrude that keeps fouling bottom plug....compression is 80 on both cylinders. Is this too low for motor to operate normally? Bill

[wbeaton]

How do you run this motor? Do you do a lot of putting around at trolling speed? I found that switching to a hotter, but still recommended spark plug on my '87 20hp stopped any fouling. A leaner fuel mix can do the same, but I'm not suggesting it.

[tashasdaddy]

has the engine ever been decarbed with seafoam deep creep?

[whatever4]

Originally Posted by tashasdaddy

has the engine ever been decarbed with seafoam deep creep?

Not familiar with it....what does it do and where can it be bought?

[whatever4]

Originally Posted by wbeaton

How do you run this motor? Do you do a lot of putting around at trolling speed? I found that switching to a hotter, but still recommended spark plug on my '87 20hp stopped any fouling. A leaner fuel mix can do the same, but I'm not suggesting it.

run motor at different speeds, not much trolling...just starts missing after 3-5 minutes ofslow running and fous the plug

[JUSTINTIME]

sounds like carb needs a tune up

[Silvertip]

80 PSI compression is on the low side. Should be over 100 and closer to 120 - 135. Before getting to carried away, decarb the engine as was suggested. SeaFoam and Deep Creep are the same product only Deep Creep is the spray version. It can be found at most auto stores and farm stores that sell auto parts. Your marine dealer may also have it but it will be more expensive (typically). Search this forum on how to do a Decarb. That removes carbon that may be causing ring sticking. When the engine loses power, immediately check for spark on the dead cylinder. You may have a coil or power pack going bad. Run a can of SeaFoam (not Deep Creep) in a tank of gas. See if that helps.

[tashasdaddy]

go to www.seafoam.com it cleans all the gunk out of the guts of you engine. like an enema

[whatever4]

Originally Posted by tashasdaddy

go to www.seafoam.com it cleans all the gunk out of the guts of you engine. like an enema

Tried it and motor idles good now....will see how it does at the lake tomorrow....thanks for the info...Bill

[whatever4]

Tried seafoam....put in lake...have same problem...going to hotter plug...cross reference to Champion L78CJ4 is DENSO W24FS-U....anybody familiar with this plug?