Compression on 1984 140 Johnson + vro

[Jeff2012]

Hello,
What should the compression be on a 1984 140 HP Johnson?
Was this the first year for the VRO?
Thanks

 

[jerryjerry05]

Re: Compression on 1984 140 Johnson + vro

The VRO started in 84(I believe)A replacement VRO pump is $350+
Change it over and pre-mix the gas 50-1
Check the small return lines for cracked and broken and missing lines.
About 120 is acceptable.
The important thing is all cylinders read about the same.
My guage was 125$ and it's perfect.
A 15$ guage just might read the same but I know mine is right!!
Just saying after the rant some guages won't read the same.
So spend a few extra $ and get a good one.

 

[Jeff2012]

Re: Compression on 1984 140 Johnson + vro

The VRO started in 84(I believe)A replacement VRO pump is $350+
Change it over and pre-mix the gas 50-1
Check the small return lines for cracked and broken and missing lines.
About 120 is acceptable.
The important thing is all cylinders read about the same.
My guage was 125$ and it's perfect.
A 15$ guage just might read the same but I know mine is right!!
Just saying after the rant some guages won't read the same.
So spend a few extra $ and get a good one.

would 110 across all 4 cyls be signs of a tired motor?

 

[BonairII]

Re: Compression on 1984 140 Johnson + vro

Your compression is fine. The fact that all cyls have even compression is a good thing.

 

[V153]

Re: Compression on 1984 140 Johnson + vro

Your compression is fine. The fact that all cyls have even compression is a good thing.

And 110 -120psi is entirely acceptable for a used motor. My 140 was a lucky find, 130psi plus in all four holes. WooHoo! Ya so long as compression is even & above 100psi or so yer good to go.

 

[jerryjerry05]

Re: Compression on 1984 140 Johnson + vro

Just picked up a 1972 85hp Everude.
Comp 120 all 4 and it started right up after setting for 5-6 years.
Way clean,better than some newer ones.J