1971 60 hp Evinrude 3 Cylinder Compression

[IWishMyBoatRan]

What should be an "okay" compression for this motor?

Cylinder 1 is 90
Cylinder 2 is 110
Cylinder 3 is 120

I know the motor is a bit rough, but is there anyway to improve cylinder 1?

 

[Watermann]

Re: 1971 60 hp Evinrude 3 Cylinder Compression

120 - 130 would be good for the age. Fog the low cylinder with oil and re-check the compression. See how much it jumps up. If it were me, I would just do a de-carb and just keep running her. That is a pretty large spread and the engine will be in need of a power head rebuild down the road in the near future.

 

[IWishMyBoatRan]

Re: 1971 60 hp Evinrude 3 Cylinder Compression

I started the de-carb process, and the engine died after about 10 minutes, can't get it to restart. Got my new fuel pump in today, heading to town for newer fuel lines.

How do you "fog" the bad cylinder?

 

[IWishMyBoatRan]

Re: 1971 60 hp Evinrude 3 Cylinder Compression

ps.. rebuild or just buy a replacement power head?

 

[Watermann]

Re: 1971 60 hp Evinrude 3 Cylinder Compression

I started the de-carb process, and the engine died after about 10 minutes, can't get it to restart. Got my new fuel pump in today, heading to town for newer fuel lines.

How do you "fog" the bad cylinder?

That's a normal procedure for de-carbing, spray seafoam in the carbs slowly at first after the motor warms up and then lay it in thick until she dies and then let sit for 10 or 15 minutes. Should start right up then. I usually change out my plugs when done with the process. If it's really thick with carbon in there or never done before you'll notice afterwards a slimey black puddle of goo run out the prop exhaust that won't clear out on the muffs, only until your out on the lake at wot running around.

Rebuild would be the least expensive and since your running a vintage 1970's I can only assume your like me and not sporting a thick wallet.

Use the engine oil fog in can for winterizing engines/outboards, just about every car parts house have cans of it.

 

[IWishMyBoatRan]

Re: 1971 60 hp Evinrude 3 Cylinder Compression

oh yeah, lots of thick slime was coming out..only problem now is it won't start. I'm pulling the fuel hoses (replacing them) and since the carbs have been rebuilt, Im going to check them as well. Will keep you updated.

Thanks bunches.
By the way, I found a 1971 60 hp powerhead for 400.00 --- good compression on all 3 cylinders...

Worth it or just buy another engine for 600-700 and part this old one out (when the time comes)

 

[Watermann]

Re: 1971 60 hp Evinrude 3 Cylinder Compression

Never hurts to have your eye out for another motor knowing your on borrowed time, then you'll have a spare on hand when the time comes. I have my sights set on a 70 Johnson for mine when the time comes.