Compression Question?

[Mark523]

I have a 1967 Big Twin 40 HP Evinrude. I have done a compression check and I have around 100 in each cylinder. Can anyone tell me what the ideal compression should be in this motor? Thanks in advance!

Mark

 

[i386]

Re: Compression Question?

The actual number isn't as important as the variance between the two cylinders. I'd say with 100psi in both you're good to go.

 

[DJ]

Re: Compression Question?

Agreed.

 

[clint]

Compression Question?

Having 100 lbs in each cylinder sounds like maintenance on this 1967 motor was kept up to specs. Thats great!
Clint d

 

[KYHunter2]

Re: Compression Question?

No kidding, sounds like, " You got a good-un" ! ! !

Just to be sure it stays , in great condition.

Do a periodic decarb, depending on the hours you put on motor.

I do one every fall, even though I run mine all year.

Its about due then. 50 hours, give or take.

Also rebuild waterpump, every couple years , and you'll have a fine motor ,for years to come.

Good - Luck,

KYHunter