Compression test results need opinions

[hwrdpromac7900]

Compression tested my saws, here's the results.
Pro Mac 8200= 160psi
Pro Mac 800= 160psi
Pro Mac 610= 165psi
Power Mac 310= 135psi

Are these numbers good?

 

[redunshee]

Compression tested my saws, here's the results.
Pro Mac 8200= 160psi
Pro Mac 800= 160psi
Pro Mac 610= 165psi
Power Mac 310= 135psi

Are these numbers good?

160 is very good on any saw. 135 isn't bad and saw should run fine everything else being equal.

 

[hwrdpromac7900]

Thanks for reply!!!

 

[nate cutter]

if you are close to sea level they are good if you are a mile high than they are great.

 

[hwrdpromac7900]

We are 586 ft above sea level.

 

[sonorachainsaw]

a mechanic once said that if the compression is good or at 145 or better at three pulls is optimum

 

[Teddy.Scout]

Then when would you want to open a saw and do a P/C check?
I feel as long as it runs and is above 11-lbs I am safe?

I had a 066 that drop below 100lbs and a ring job brought it back to 155lbs.

 

[Justsaws]

Those are very good numbers but if you are having trouble with the saws a cold test and hot test can paint a better picture. It is very helpful on the older saws with impulse powered oilers as sometimes a bar lube ends up in the cylinder after cooling down and sitting for a while, the same can be said for mix sitting on the lower side of the horizontal cylinder. The extra lube is burned off quickly in the much dismissed first start thick cloud of smoke that many people associate with the older saws.

If the saws are running good and producing good power than I would leave it be.

 

[Justsaws]

Then when would you want to open a saw and do a P/C check?
I feel as long as it runs and is above 11-lbs I am safe?

I had a 066 that drop below 100lbs and a ring job brought it back to 155lbs.

Depends on the saw. I would not think that a 066 with a 100lbs of compression would be worth carrying around. Usually as the saw drops compression starting and idling become erratic and extra work. Compression testing gives a very limited amount of information and on this site is regarded with way way way more respect than it deserves. Just like the tach..

On most modern brands there is no need to tear down a saw to check rings, just pull the muffler and poke the rings.

No movement=stuck rings, tear it down and fix problems. Stuck rings are a symptom.
Very little push in= good
Very little side to side=good
Lots of movement everywhere=tear it down.

 

[litefoot]

Those are very good numbers but if you are having trouble with the saws a cold test and hot test can paint a better picture. It is very helpful on the older saws with impulse powered oilers as sometimes a bar lube ends up in the cylinder after cooling down and sitting for a while, the same can be said for mix sitting on the lower side of the horizontal cylinder. The extra lube is burned off quickly in the much dismissed first start thick cloud of smoke that many people associate with the older saws.

If the saws are running good and producing good power than I would leave it be.

Depends on the saw. I would not think that a 066 with a 100lbs of compression would be worth carrying around. Usually as the saw drops compression starting and idling become erratic and extra work. Compression testing gives a very limited amount of information and on this site is regarded with way way way more respect than it deserves. Just like the tach..

On most modern brands there is no need to tear down a saw to check rings, just pull the muffler and poke the rings.

No movement=stuck rings, tear it down and fix problems. Stuck rings are a symptom.
Very little push in= good
Very little side to side=good
Lots of movement everywhere=tear it down.

Justsaws,
VERY good posts! There's always something new to learn.
JP