Low compression on my new Stihl MS362

[lone wolf]

This is gold. (Maybe)

If you are needing to shake it - to get it going- something else may be going on here.

Let’s all turn our attention to this new detail.
Does anyone out there EVER have to shake a saw when it bogs in the cut?

Personally I only ever have to lift a saw, if it bogs. It spools back up and away we go.

If it’s refusing to rev once the weight is off the bar-that’s a whole new thing (to me)

I’m not discounting what I feel is lower compression, not at all... and I may be missing something and barking up the wrong tree... but this info about having to shake the saw has my attention from a mechanics standpoint.

What say all of you?

If its an accurate observation on his part not coincidence?

 

[lone wolf]

Until someone shows me what compression adapter/hose they use for this small spark plug hole i'm not sure what to make of the compression readings without a squish measured. My 462 was at .031 and now at .021 and I'm at 120psi cold with the 10mm adapter that does not have the schrader in it. I don't use the decomp valve really ever on any saw. But i don't have any problems in the cut, and i can hang the saw by its pull cord for a long time before it eventually forces the piston over.

I mentioned that to him and suggested he test some other small plug engine for comparison. I had the same problem when I got my first 10 mm saw the comp was like 120-130 in everything in my shop ! Logic said they ain't all junk even a trimmer or blower has 150 or more. He did post a pic of his gauge way back on here somewhere if you can find it. Hard to trouble shoot over the net through another party isn't it?

 

[James Sawyer]

maybe shaking is not the correct term...I have to lift the saw and rock it up and down in kerf to get it going. I don't let off the throttle sometime is starting right away sometime it take a bit longer. But when the saw stop three to five times in a 15" cut that's a lot for the clutch to have to slip. The compression isn't at question its been checked 6 times with at least 4 different gauges by 3 people...we're all getting the same readings. Stihl is saying that is the correct compression for this model. Both shops say its right where it should be as is Stihl. I been busy today at work or I would run out to my car and check the if I have the quick stop...it was still dark when I got to work this morning.

 

[Derrick Sawyer]

U dont have quickstop, but your lisle gauge has the Schrader in the hose right? The hose that went directly into the 034 saw? Reading is fine...then how do u screw the same hose into the 362? Snd u said the shop had the same setup. U need XTANGS comp tester

 

[James Sawyer]

The Schrader valve is on the adapter, the vent is on the gauge. There is nothing wrong with my gauge.

 

[Derrick Sawyer]

So you have another hose that is just like the one you show here with the 460 and 034, except the other hose is 10mm thread instead? Or do you screw your hose into a small piece of metal that is 10mm thread? I have run hundreds of compression tests on cars due to a maniac boss who made us check for every tune-up and buyers check. Not only did the hoses go on the cylinder without additional adapters but the volume of the combustion chamber is bigger than a few cc. The chainsaw combustion is what size? I don't know exactly, by lets just hypothetically say that my 70 cc saw compresses 10:1 so the combustion chamber is 7 cc. then i have my compression tester with schrader in the hose, screw that into a hollow metal adapter that has an air volume of 1 cc, then into the spark plug hole. Now the piston is compressing to 8 cc not 7 cc, that difference would make my saw read 120 when its really 140 psi.

 

[James Sawyer]

So doesn't look like I have quick stop

 

[James Sawyer]

So you have another hose that is just like the one you show here with the 460 and 034, except the other hose is 10mm thread instead? Or do you screw your hose into a small piece of metal that is 10mm thread? I have run hundreds of compression tests on cars due to a maniac boss who made us check for every tune-up and buyers check. Not only did the hoses go on the cylinder without additional adapters but the volume of the combustion chamber is bigger than a few cc. The chainsaw combustion is what size? I don't know exactly, by lets just hypothetically say that my 70 cc saw compresses 10:1 so the combustion chamber is 7 cc. then i have my compression tester with schrader in the hose, screw that into a hollow metal adapter that has an air volume of 1 cc, then into the spark plug hole. Now the piston is compressing to 8 cc not 7 cc, that difference would make my saw read 120 when its really 140 psi.

My gauge has a adapter build into the hose not removable, I have another 10mm adapter that go from that to the adapter on the hose.

 

[X 66 Stang347 X]

His adaptor May look like mine. I use it for cylinder blow-by

 

[Derrick Sawyer]

Yes that is the adapter I have and my 462 read 120psi with that setup but runs like a scalded cat..well not quite but anyway that will underestimate real compression....try running saw and when it bogs down stop the saw...can u turn the chain by hand...pull the plug, is it dark or light? Or return to dealer on warranty claim

 

[James Sawyer]

The plug is light on the dark/black side but I would say it pretty normal. I the 1st shop pulled it when they tested it and agreed, I was standing right next to them when they tested my saw. Same compression setup as mine.

 

[X 66 Stang347 X]

With a known good gauge with the adaptor I’m getting 120psi cold

 

[X 66 Stang347 X]

I would double check their carb adjustment. If it's to lean it wont have the torque. I run mine a little richer than normal when running a max length bar. something to try.
page 101 has the steps for adjustment on the 362

 

[James Sawyer]

I would double check their carb adjustment. If it's to lean it wont have the torque. I run mine a little richer than normal when running a max length bar. something to try.
page 101 has the steps for adjustment on the 362

120psi cold ...same as the 2nd shop got. The 1st, 2nd shop and I got 110psi on hot compression test.

 

[James Sawyer]

I would double check their carb adjustment. If it's to lean it wont have the torque. I run mine a little richer than normal when running a max length bar. something to try.
page 101 has the steps for adjustment on the 362

Its tuned to 13,400 RPM when I ran the cut test on 15" and 23" logs.

 

[Ronaldo]

Its tuned to 13,400 RPM when I ran the cut test on 15" and 23" logs.

That's fine and all, but tune it in the wood for best results.

Sent from my SM-S320VL using Tapatalk

 

[lone wolf]

So you have another hose that is just like the one you show here with the 460 and 034, except the other hose is 10mm thread instead? Or do you screw your hose into a small piece of metal that is 10mm thread? I have run hundreds of compression tests on cars due to a maniac boss who made us check for every tune-up and buyers check. Not only did the hoses go on the cylinder without additional adapters but the volume of the combustion chamber is bigger than a few cc. The chainsaw combustion is what size? I don't know exactly, by lets just hypothetically say that my 70 cc saw compresses 10:1 so the combustion chamber is 7 cc. then i have my compression tester with schrader in the hose, screw that into a hollow metal adapter that has an air volume of 1 cc, then into the spark plug hole. Now the piston is compressing to 8 cc not 7 cc, that difference would make my saw read 120 when its really 140 psi.

Yup! And a wrong schrader valve can wreck havok also as i found out!

 

[lone wolf]

Its tuned to 13,400 RPM when I ran the cut test on 15" and 23" logs.

Do you have any Stihl machines like blowers trimmers pole pruner that has that smaller plug to cross check this gauge?

 

[James Sawyer]

I've never tuned a saw in wood, I just have tune no load like the shops do? What's your procedure and what is the top RPM unloaded afterwards? I've tune/jetted a lot of motor cycles there all tuned under load, going by the spark plug. Never heard that on a chainsaw. Right now...I don't want to tune this saw or make any adjustments. The shop I bought it from tuned it...not sure if the 2nd shop make any adjustments...it is idling higher then when I 1st checked/installed the tach. The 2nd shop may have tuned it, but never said so...I don't know. I think last time I ran the saw it was idling at 3400rpm, I don't remember if the chain was turning or not...at the time I didn't really pay that much attention to the idle just the max RPM and how it cuts. The tuning isn't that far off that i can cut 15" of wood and have the chain stopping like it is. No calls todays from the 2nd shop nor was there a call from JD the NW district Stihl manager, he should be in the office tomorrow. unless I miss understood his answering machine message...he could have said " out thru April 5th". I don't remember...I'll call again tomorrow.
My wife dad isn't doing good so leaving out of town at noon tomorrow (heart issues) . I'm going to sit on the saw until I talk to JD like other have suggested...see what he has to say. Boy it would be nice just to get out of this saw...it been complete stress on me getting hosed out of $1000. Not sure how things are in your home but it take me a while to save for something like this with my mad money, trying to tell my wife I need another saw when I have 5 other saw in the barn...she not going for that! My wife the best thing about me so not going against that. She got a serious photographic memory, she can read a book and a year later read it back to you without the book almost word for word. She a farm gal...knows almost every tool I have and don't ...have plus she can use them. Not the typical wife that's for sure.
When I met her...my family been hunting elk here in Oregon for over 140+ years. 1st white man in the Umpqua Valley Dr. James Cole. She told me at one point she had a rifle but I didn't pay much attention, so I going elk hunting with the family. She mention she has hunting rifle so I invite her. We're on are way down to Roseburg and she says I haven't shot my gun in a while maybe we should pull over and check it. So, I pull off at Curtain drive up in the woods...I stick piece of notebook paper with 1" bulls eye. She get this rifle out and thumbing shells in it. These rounds are as big as her thumbs...375 big bore, 37 caliber. She shoot 2 round , off hand, open sights both in the black. I picked up the cases and I couldn't wait to show, brag about this woman. She something...drive semi's old school 5/4 type trucks, break horse, ran race horses, had her trainer license. Never rode a motorcycle or 4 wheeler when we met.. never used a hand clutch...Busted the bead on two of the 350 warrior tires sliding it by noon the 1st day out at the dunes. Trust me I don't get away with anything with her...loosing $1000 hurts... I really wanted this saw! That why I spent the time to get it just the way I wanted it, pretty proud of it when I finished it, now to have it run like it does is pretty upsetting.

 

[James Sawyer]

Do you have any Stihl machines like blowers trimmers pole pruner that has that smaller plug to cross check this gauge?

I have 3 stihl weedeaters, but not sure any of them are 10mm plugs. A Husky pole saw, husky hedge trimmer and shindaiwa packpack blower...I guess I have a Homelite top handle but I don't count that as a one of my saws. I have little piece of ground with about 1/2 to 3/4 acre yards with a lot of flower beds so i have few tools.