Evinrude 10 HP 1957 Model 10014

[Evinrude 25]

Hello,
I just pick up Evinrude 10 HP 1957 Model 10014-10015. Compression check is 60/60 psi per cylinder since it sat long outside. Spray some WD-40 inside the spark plug hole and got 70/71 psi.
I would like to know if it is an acceptable compression before I tear down to restore it.

[Bob Wight]

My 10hp Johnsons both run real good with about 80-83psi. If your motor sat idle for a long time, it might just be stuck rings. You might try to get it running with fresh fuel, oil and some BRP Engine Tuner and see if compression doesn’t come up a bit more. You can also pull the bypass covers off and push in on the piston rings to see if they have any spring or bounce to them. If not, then they are stuck.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[dave-bernard]

Or a blown head gasket .between the 2 cyl.’s

• This reply was modified 4 years, 6 months ago by dave-bernard.

[Evinrude 25]

Does anyone know the factory compression number? 90 psi when brand new? I am planning to hone the cylinder and fit the new rings for it but I have to do some search for the ring part number.

[fleetwin]

I doubt it needs rebuilding…Might be your gage is inaccurate… Like Bob says, you can sneak the intake covers off pretty easily without making a mess, you might try peaking at the intake sides of the pistons…But, it sure couldn’t hurt to pull the head to have a better look.
Once again, I would not pull this powerhead apart unless you find evidence of actual damage or stuck rings….

[crosbyman]

just run it as suggested with some kind of decarb agent (Seafoam,MewrcPOwer tune, Evinrude engine cleaner etc….) don’t fix it if it ain’t broke 🙂

Joining AOMCI has priviledges 🙂

[Evinrude 25]

Open the intake cover, the ring and piston looks clean and no carbon deposit. Open the head, the cylinder looks good too.

[seakaye12]

Through the intake cover you should be able to use something to poke at the rings; you should see movement…a slight springy action as you depress them in their grooves. If you see that, the rings are not stuck.

[Evinrude 25]

Yes, I could move the ring by poking at it. It moves back and forth freely. Let me try to fire it up with 70 psi/68 psi of compression. Even I spray more WD-40 on the side of the ring through the intake cover, no improvement on the compression! The top crank shaft seal got leak too. It is time to replace it.

[amuller]

If it were mine I’d run it under load for a while, dosed up with the OMC engine tuner stuff. It’s not unusual for this to free up mildly stuck rings. and gaskets/parts are getting more and more expensive. And I dislike messing with a bunch of loose needles. You might feel differently. Of course, you probably can’t run it under load in a tank, so if you are into winter (which we definitely are in Minnesota) and you want to have it ready for next season….

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