Low Compression on 044...why?

[Philbo]

I was at my local Stihl shop recently picking up some different stuff and decided to drop my 044 off with them to check over as I've been having a problem with it cutting off on me once warm. Once warm, I'll set the saw down (still running) to move something, etc. Go to pick it back up and it cuts off on me as soon as I start to move it. Blipping the throttle right before moving it seems to help, but I wanted someone hopefully more qualified than myself to troubleshoot it. I don't really have the time at the moment (just bought a house and doing tons of renovation) or the experience with saws yet to really know what to look for. It's summer and I'm not running the saws too much this time of year.

I ask them for a new spare air filter, change the plug, fuel filter, inspect the carb/possibly rebuild, check the clutch springs, and to check the compression (I don't have a gauge.)

I got the saw back and was told there was a leak/busted fuel line (they replaced.) The carb was cleaned, but apparently did not need rebuilding. The clutch springs are apparently fine. The compression was 97lbs....

The guy at the counter said it so casually. I was confused and said "damn...isn't that a bit low?" He replies "yeah, it seems a little low, but still plenty to do some cuttin" I paid the bill and left, wondering to myself how I could have cut up 7 cords of wood in the last year with that low compression?

The 044 seems a little tired to me, but it seems to run relatively well/strong to me. Always starts right up. I don't have that much of a frame of reference, but it will definitely hand it to my old muffler-modded 346xp in the bigger wood. I definitely used it with a 28" bar with skip chain to buck up a 40" white oak one afternoon for a friend and it handled it ok.

I'm including a couple snaps of the cylinder and the piston the best I know how...from a cell phone pic with the muffler cover taken off. Sorry if these don't tell you anything, but to me the cylinder and piston both look to be in great shape, but what do I know? :msp_tongue: I can run my fingernail up and down the piston with no snags.

What's going on with that low of compression? Should it even start and run decent with 97 lbs? Maybe I should get my own damn compression gauge...:hmm3grin2orange:

Edit: Bahh, somehow the pics are upside down...don't know why, they didn't look like that when I uploaded them...

 

[a. palmer jr.]

I was at my local Stihl shop recently picking up some different stuff and decided to drop my 044 off with them to check over as I've been having a problem with it cutting off on me once warm. Once warm, I'll set the saw down (still running) to move something, etc. Go to pick it back up and it cuts off on me as soon as I start to move it. Blipping the throttle right before moving it seems to help, but I wanted someone hopefully more qualified than myself to troubleshoot it. I don't really have the time at the moment (just bought a house and doing tons of renovation) or the experience with saws yet to really know what to look for. It's summer and I'm not running the saws too much this time of year.

I ask them for a new spare air filter, change the plug, fuel filter, inspect the carb/possibly rebuild, check the clutch springs, and to check the compression (I don't have a gauge.)

I got the saw back and was told there was a leak/busted fuel line (they replaced.) The carb was cleaned, but apparently did not need rebuilding. The clutch springs are apparently fine. The compression was 97lbs....

The guy at the counter said it so casually. I was confused and said "damn...isn't that a bit low?" He replies "yeah, it seems a little low, but still plenty to do some cuttin" I paid the bill and left, wondering to myself how I could have cut up 7 cords of wood in the last year with that low compression?

The 044 seems a little tired to me, but it seems to run relatively well/strong to me. Always starts right up. I don't have that much of a frame of reference, but it will definitely hand it to my old muffler-modded 346xp in the bigger wood. I definitely used it with a 28" bar with skip chain to buck up a 40" white oak one afternoon for a friend and it handled it ok.

I'm including a couple snaps of the cylinder and the piston the best I know how...from a cell phone pic with the muffler cover taken off. Sorry if these don't tell you anything, but to me the cylinder and piston both look to be in great shape, but what do I know? :msp_tongue: I can run my fingernail up and down the piston with no snags.

What's going on with that low of compression? Should it even start and run decent with 97 lbs? Maybe I should get my own damn compression gauge...:hmm3grin2orange:

Edit: Bahh, somehow the pics are upside down...don't know why, they didn't look like that when I uploaded them...

I'm suspecting the compression gauge is a little off. My 044 was very hard to pull over, you really had to use some muscle to pull the rope, is yours like that? The piston looked good to me. I would look at buying a compression gauge.

 

[cutforfun]

Your dealer is an idiot. Go cut some wood, nuff said

 

[walexa07]

Sounds like their compression gauge is reading low. I'd get my own and confirm. I would think it wouldn't even crank with just 97 psi compression. Maybe they just pulled the starter rope once when they took the reading - new guy or something - and the guy at the parts counter does not know enough about saws to save his life??

As good as the pics you posted show, I'd want to check the tune as well. Get a comp. gauge and a tachometer. Read up on tuning as well. A poor tune can make one run like it's tired. If it pulled the 28" ok fully buried and is completely stock, I'd say it was doing its part.

Waylan

 

[tlandrum]

you need to check the compression yourself

 

[angelo c]

Me smells a rat. Saw wont run at 97psi compression. Cant really make out the piston or rings. Take the muffler off then take a few pics closer to the ring lands.

 

[Philbo]

As far as being hard to pull over, I wouldn't say that. Not quite like trying to crank my 288 without the decomp pressed in... I just held it up by the starter rope with the b/c on and it took about 15 seconds to reach the end of the rope. Don't know if that tells you anything. The saw is stock except for a DP muffler cover and the 28" was definitely fully buried in that huge oak and did alright.

Thanks for responses. I'll look into getting my own gauge and maybe a tach if I can set some saw money aside.

I pulled the muffler off and was able to get a bit closer, but I don't know if these shots are any better than the first ones...sorry again about the upside down pics.

 

[3000 FPS]

I looked at your second set of pictures and the piston looks fine to me. There is no way your saw is at that low on compression.

 

[XSKIER]

May be the way I'm looking at the last pic, but the intake side of the cylinder looks not so good. The dealer may be right, tired but still able to cut wood.

 

[adminfti]

Im rebulding mine and my ring are worst than you and i get 120 psi on my Jonsered 451. Like the other say.. The gage coult have a misreading. An air leak somewhere...

 

[barneyrb]

Did the dealer measure compression with the decomp pushed in? I know some of the late 044's had them.......

 

[angelo c]

Ok. The upside down pic thing is making my ipad nuts.....hehe
Seriously i think you need to take a few better pictures and if you can take them of the entire piston from the rings down( or up in your camera case). You somehow managed to photo the least important sections of the piston or there is absolutely no wear. Can you borrow a vac tester from autozone to see if there are any crazy leaks? Some auto parts stores will let you "borrow" tools if you put the value on a credit card and return the tool they remove the charge. Free.
Also it is very common to not have any scoring on the intake side and the exhaust side be wiped out.

 

[Trx250r180]

hold the saw in the air by the pull cord ,if it unwinds fast you have low compression,my saws stay in the air but they have 200 plus psi ,if it falls slowly rolling over you have good enough comp to cut wood with

 

[Stihlofadeal64]

Good advice given so far. I can't see the intake side of the cylinder clearly enough -- it could be a bit scored from ingesting saw hash from a bad filter (I can't tell really for sure). With the machine marks in your piston, it is hard for me to believe that you're having compression problems, but I may be wrong. As suggested I would definitely get a quality tester and check the compression for myself. (I can't imagine the saw starting with less than a 100psi) and with what you've spoke of it being strong buried up in oak I have to question the comp tester (and the experience) of the guy at the counter.

If indeed it was low on compression, he should have never tried to tune it any how...

 

[Wood Doctor]

hold the saw in the air by the pull cord ,if it unwinds fast you have low compression,my saws stay in the air but they have 200 plus psi ,if it falls slowly rolling over you have good enough comp to cut wood with

Interesting... I just tried that test with my 5-year-old MS 361 with about 600 hours on it. It failed to unwind the cord. I started the saw and tried again. It failed to unwind again. Looks like it has good power, and it does. On the other hand, it also has rather low weight for the power that it delivers.

Regardless, I'll check a few other saws as well this way.:msp_thumbup:

 

[Trx250r180]

Interesting... I just tried that test with my 5-year-old MS 361 with about 600 hours on it. It failed to unwind the cord. I started the saw and tried again. It failed to unwind again. Looks like it has good power, and it does. On the other hand, it also has rather low weight for the power that it delivers.

Regardless, I'll check a few other saws as well this way.:msp_thumbup:

i was taught that by a couple of loggers when looking at used saws ,quick way to check compression ,if it unwinds quick ,don't pay as much for it even if it seems to run ok ,will be needing a rebuild soon

 

[mdavlee]

I've had a few saws that wouldn't budge even with a b/c and full of fluids. Dang husky 2100 and 288.

 

[elanjoe]

I've had a few saws that wouldn't budge even with a b/c and full of fluids. Dang husky 2100 and 288.

stihl ms 250 will hang on the rope all day and wont budge !!!

 

[o8f150]

pics look good,,,, I bet the dealer was just wanting your saw hoping you would just junk it by leaving it with them

 

[Wood Doctor]

Weight Question?

stihl ms 250 will hang on the rope all day and wont budge !!!

Just tried it on a vintage Stihl 084. It had no problem unwinding the pull cord with its 23 lb mass. It was impossible even to pick up the 084 with the pull cord handle. She laid there on the floor like a mammoth stone. :msp_unsure:

Seems like weight of saw is rather important, but I still like this test because heavier saws should still jerk your arm off on a cold start. I'm moving on to test the rest of my saws for further testing of this hypothesis.