What are good compression numbers?

[davidwyby]

My saws (in sig) all give me 150 psi except the 266 which is 180. Should I be getting rings for the rest while they’re apart? I know 150 isn’t “too low”, but what is good/new for these saws?

Thanks

 

[Dub11]

Last saw I checked was a clean ms290 and it was a little over 150psi. I think your good.

 

[Deets066]

Depends on your elevation really, but typically 150 is perfectly normal. At my elevation I usually don't see a stock saw over 150

 

[huskyboy]

Stock 394 here at 151’ above sea level is 160 psi on my cheap tester. I think your close on the 395.

 

[KZ1000]

I re-ringed two saws with 130psi before I found out about compression at 5600'

 

[davidwyby]

I’m below sea level. Thanks dudes.

 

[Marshy]

I’m below sea level. Thanks dudes.

Well,they don't run well under water so you might want to recheck your strategy.

 

[Stump Shot]

If they are apart, take a ring off and put in the bore to check for excessive ring end gap, this will tell you if they need changed or not. Compression testing can only point you in a direction, and at 150 really isn't saying much more than normal. Should be over 100 to run at all, and repairs are quite necessary at this point.

 

[davidwyby]

If they are apart, take a ring off and put in the bore to check for excessive ring end gap, this will tell you if they need changed or not. Compression testing can only point you in a direction, and at 150 really isn't saying much more than normal. Should be over 100 to run at all, and repairs are quite necessary at this point.

Yeah, low numbers are everywhere. 150 seemed good until I tested the 266. Now I’m looking for good high end target numbers, not junk numbers.

@Marshy -42’. Lowest town in the valley is Calipatria @-180’

 

[Deets066]

Yeah, low numbers are everywhere. 150 seemed good until I tested the 266. Now I’m looking for good high end target numbers, not junk numbers.

@Marshy -42’. Lowest town in the valley is Calipatria @-180’

At -42 feet, 150 lbs is probly on the low end

 

[davidwyby]

At -42 feet, 150 lbs is probly on the low end

That’s what I’m thinking if a 266 with light scoring out of the junk pile is 180...but I don’t know what these saws would have been new or just broke in.

 

[Stump Shot]

A 266 has a pretty small combustion chamber compared to most saw's. Just like a 181/281 does, they run 185 plus normally. Most others will be much less and doesn't make them bad necessarily.