Is 125 pounds compresion enough?

[robfromaz1977]

I have an old 266 SE Husky that I got 10 years ago from a friend who ran straight gas in and locked it up. I put a ring in it and made it live. Lately I have had some trouble keeping it running right. Just out of curiosity I decided to check the compresion and at best has 125 psi. Is this enough to run on or should I start looking into tearing it down and buying stuff? Thanks in advance.

 

[Meadow Beaver]

It will run on125psi, but it's nothing to brag about.

 

[GASoline71]

120 is right about where you need to start lookin' at a rebuild. So you're dang near there.

Gary

 

[Meadow Beaver]

120 is right about where you need to start lookin' at a rebuild. So you're dang near there.

Gary

Yeah 180-200psi is a good range :greenchainsaw:

 

[robfromaz1977]

Thanks for the fast replys. Is 180+ a realistic achievable number? My other 266 has 150 psi on it.

 

[Meadow Beaver]

Thanks for the fast replys. Is 180+ a realistic achievable number? My other 266 has 150 psi on it.

I'm just messin' witcha, you probably won't see a stock saw with 180psi.

 

[robfromaz1977]

I'm just messin' witcha, you probably won't see a stock saw with 180psi.

I was hoping so! I am not new to running saws but am just getting interested in working on them. I have only been into one saw, my 266, past normal maintnance.

 

[lone wolf]

compression

bet you have trouble keeping it idling when you set it down sounds to low to me it will just drive you crazy you got to decide if its worth fixing or should you look into buying another

 

[litefoot]

What altitude are you measuring the compression? Add roughly 3% to your reading for every 1000' elevation. If you are in Flagstaff, your compression adjusted for elevation is closer to 145 psi.

 

[robfromaz1977]

bet you have trouble keeping it idling when you set it down sounds to low to me it will just drive you crazy you got to decide if its worth fixing or should you look into buying another

Yeah thats what it tends to do.

 

[robfromaz1977]

What altitude are you measuring the compression? Add roughly 3% to your reading for every 1000' elevation. If you are in Flagstaff, your compression adjusted for elevation is closer to 145 psi.

I live in Springerville and the elevation here is just a tad under 7000'. I do most of my wood cutting even higher up around 8500 to 9000'.

 

[blsnelling]

No. Time to tear it down.

 

[nate cutter]

so about 162 psi at sea level

 

[056kid]

I have run old 44/6s that couldent have had more than 110 lbs,

thats wheen you really learn how to keep a chain cutting efficently!

 

[longbar]

80lbs is when a saw will start not running. I just rebuilt a saw with 80 and it would run but wouldnt start easy and didnt always wanna idle. 120 is decent compression and Ive never had issues with saws that high. I think anything above that is good. I dont tink ive ever had a saw over 130 but Ive never thought about the sea level thing so maybe they are higher.

 

[mtngun]

I live in Springerville and the elevation here is just a tad under 7000'. I do most of my wood cutting even higher up around 8500 to 9000'.

As Nate pointed out, 125 psi at 7000' is actually pretty decent.

I live at 4600' and my "strongest" saw at the moment blows 145 psi.

When I hear about these guys with 170 - 180 psi it makes me green with envy.

 

[litefoot]

The altitude factor at 7000' is actually .8106, so your reading is about 19% lower than sea level...124 becomes 148 psi. Still, though, the fact that the saw was straight-gassed.....hmmm....how did the p&c look when you changed out the rings?

 

[robfromaz1977]

The altitude factor at 7000' is actually .8106, so your reading is about 19% lower than sea level...124 becomes 148 psi. Still, though, the fact that the saw was straight-gassed.....hmmm....how did the p&c look when you changed out the rings?

If my memory is right they looked ok. No chrome was missing and I don't remember any scoring. I ran that saw for at least 40 cords of wood the first year after putting a ring in it and ran it for the last 9 years as a backup to my 395. Maybe I will have to tear it down and see what I got.

 

[litefoot]

If my memory is right they looked ok. No chrome was missing and I don't remember any scoring. I ran that saw for at least 40 cords of wood the first year after putting a ring in it and ran it for the last 9 years as a backup to my 395. Maybe I will have to tear it down and see what I got.

That's up to you...but you can look at the piston through the muffler (exhaust port) opening. If it's been running strongly up until now, I'd suspect something other than the top end.

 

[zeke573]

I agree, take off the muffler and see how the piston looks. I had a 266 that ran fine at 110psi but the piston was showing some wear, so I replaced it. Your problem may have nothing to do with compression. An air leak test would be a good idea and also a carb inspection. Sometimes the saw will be hard to start or restart if compression is an issue. The 266 is worth fixing because it's such a great saw. I've fixed many of them for usually not much than the price of a new piston and carb kit. I really like the 266/268/272 saws.