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Low compression on my new Stihl MS362

Discussion in 'Chainsaw' started by James Sawyer, Mar 21, 2019.

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  1. James Sawyer

    James Sawyer ArboristSite Operative

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    I fell a couple trees with my new MS362 today. I had the shop tune it at the time of purchase. The saw just didn't cut like I thought it should, it didn't take much to stop the chain. My saw has a tach and the hour meter which shows .3 hours and I only ran 1/2 tank thru it. I wanted to baseline the compression so I'd have a reference and it came in at 110psi on three tests (WOT). There is nothing wrong with my compression gauge I've used it lately on two other saw's I have and trust the gauge. I'm really nerves after reading other members post on new saw compressions. Should I take this saw in for warranty or is it too early to tell. I'm really thinking about running a camera into the cylinder to see how it looks. The saw power is so low too dangerous to use to fall anymore trees. [​IMG]
     
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  2. pioneerguy600

    pioneerguy600 Lost in Space Staff Member

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    If that compression number is correct, take that saw back immediately, that`s very low and won`t come up much when broke in, no sense in waiting. Let the dealer pull the muffler and take a look at the piston.
     
  3. boltonranger

    boltonranger ArboristSite Guru

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    110? Ah that’s a shame. It seems we often read about claims of bad gas when a saw goes in with problems. I’m going to assume it was good fresh mix. Would it be worthwhile to bring your gas can in as well?

    Although I don’t know a way to check its “strength” — at least your Dealer could see for himself...
     
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  4. drf255

    drf255 BAD CAD

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    Make sure decomp wasn’t depressed during comp testing, but that wouldn’t explain low power.

    I’d say to check the piston, but once you touch anything you’ll become “it” and the dealer may not honor things.

    I like the tach setup. Looks factory.

    Take it back ASAP to the dealer. The sooner the better.
     
  5. jltrent

    jltrent ArboristSite Operative

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    Take it back ASAP. It does not take, but a few seconds/minutes to destroy a piston and possibly a cylinder with an air leak, to lean of a setting and of course bad gas. In my early days I was tinkering around with one making it run even though not right doing everything to try and get right and destroyed the top end in just a few minutes and I mean very few minutes. It turned out to have an air leak. It could even have a ring sticking or a piston/cylinder that got through QA and should have been declined. Wifes brother who is a 35 year Mahle employee in the piston division told me a story of a new inexperience employee letting some pistons get through that didn't meet specks and the company had to deal with it.
     
  6. James Sawyer

    James Sawyer ArboristSite Operative

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    The fuel in the saw was what the shop put in, they filled both the oil and the fuel tanks, then tuned my saw. I installed an MS462R oiler, changed the dwg and installed the tach. I started the saw ran it just enough to check the tach. Yesterday I fell two trees both leaners , one I had to pull a bit. I was having trouble with the face even, I just could load the saw or the chain would stop. I'm doing the back cut on 1st tree and it started to go and huge hinge couldn't keep the saw cutting. I thought well its not broke in. I squared the butt on that tree, then went to fall the next one. This tree I had to pull a bit to get it in the lay. Same problem... this tree had a bigger hinge when it went just couldn't keep the saw cutting... neither tree needed a wedge, so the bar wasn't pinched. I let the saw idle a bit to cool then shut it off, when down to the house and check the compression. Majorly bummed... I have a small 5mm camera with a light build in that connects to my phone. I think I'll slide it in thru the plug opening and see what the cylinder looks like. Unless the compression release is faulty and yes I pulled the release back out when I pulled the cover. The saw does flood pretty easy...funny I was just in the shop yesterday picking up a couple plugs and had their tech check it because I just thought that not right to have to hold the throttle wide open to get it to start.
     
  7. pioneerguy600

    pioneerguy600 Lost in Space Staff Member

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    Is that tach an approved by Stihl modification? Reason I ask is a friend took his saw back for the dealer to check out a carb/fuel problem and the dealer would not touch it as the owner had drilled 6 holes in the airfilter cover, he stated it was not a stock saw anymore.
     
  8. Okie

    Okie Addicted to ArboristSite

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    Take it back ASAP. (be aware that they may want to shift the blame for the saw's weakness to you and void any warranties)

    The longer you wait or the more you fool around with the saw the more chance that you voided any warranty becomes an issue. (appears maybe you are in the voided warranty area already)

    keep us posted on the results?
     
  9. lone wolf

    lone wolf MS 200T King

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    Wait for it !!!!!!
    Ethanol did it!!!!!!
     
  10. wcorey

    wcorey ArboristSite Guru

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    Undo any mods you did like the dogs, oil pump and tach before bringing it back.
     
  11. lone wolf

    lone wolf MS 200T King

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    Good catch!
     
  12. dmb2613

    dmb2613 ArboristSite Guru

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    I think the shop did the changing
     
  13. James Sawyer

    James Sawyer ArboristSite Operative

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    The shop looked at my saw yesterday, they didn't seem to care about the mods. They thought the tach was a good Idea. I hear ya on the oiler thou because if I get a replacement, I'm out $100. But this is a good shop so I'm not so worried about the mods. ...its a dwg and a tach, there's no holes... the tach is sealed in the cover. The tach is inductive so no mods to the saw at all that isn't factory other then the cover. Plus there's the winter and summer plug if there concern about a leak to the filter...the saw only has .3 total hours on it. Yesterday when I had the saw in at the shop because of the flooding and I thought something was wrong with it. At that time they saw the hour meter was at 0 hours...hadn't ran long enough to even give a reading. It would be pretty hard to say I did something to the saw. The shop ran my saw yesterday. I think its best to just take it in...as suggested. The way I look at it I did what was required to make sure the saw was square with the shop, they told me there was nothing wrong with the saw run it. I had flooded it! I wondering if the compression release is faulty...the saw idles fine thou. Not sure but since it new...going to let them figure it out. Taking the saw in on my lunch...I have my camera here so if need be I'll look in on the cylinder with them.
     
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  14. grizz55chev

    grizz55chev Tree Freak

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    No need for a camera, just pull the muffler!
     
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  15. lone wolf

    lone wolf MS 200T King

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    Wait, now does it feel like more compression and also run better? If so you had the release on a little when tested.
     
  16. James Sawyer

    James Sawyer ArboristSite Operative

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    ok...back from the shop. 110psi on their gauge, Stihl doesn't spec compression on their saws the shop said. The shop in no-way was trying to side step my concern. They started my saw several times, ran the compression test 110psi same as I got. I asked them what they thought of that.. they where as surprise as me. I got the impression they never ran compression on new saw? So they pulled a new MS362 off the shelf, never had fuel in it, ran the same compression test 110psi. They took my saw out to their test log (fir ~22") and ran several test cuts...basically full bar length cuts. Nice chips and they where able to put some load on the saw. The chain stopped several time, same as I was having. They thought the saw was fine, possible new engineering on the cylinder and they just test low on a static compression. They would have pulled the muffler earlier and said so but they say the saw runs pretty good... no point. They think I should just run the saw and see how it is once it breaks in...it has .4 hour now. I checked the max they ran on my tach RPM 13,200 during their testing. I don't know...not sure I like these new EPA saw. Makes me appreciate my old school 034av. I think I'll run my camera into the cylinder when I get home just to look around I'm just not feeling great about this new saw.
     
  17. lone wolf

    lone wolf MS 200T King

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    Try spraying soapy water on the plug base and compression release white pulling the pullcord carefully to check for leaks then pull the muffler something is def wrong with that saw !I dont care what they said! I wouldn't sell a used one with that shitty compression!
     
  18. av8or3

    av8or3 ArboristSite Member

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    You know, it may just need to be broken in. My 462’s chain stopped many times the first time I ran it. I adjusted my technique and kept cutting. But I ran it for about 1 1/2 hrs that first day. The next day the saw was noticeably stronger. It has been noticeably stronger each time I have run it and I think I have about 4-5 hours on it. I was counting tanks, but lost count. Maybe it’ll come around. I mean they showed you a brand new one is the same so run it like you stole it and it will either fail or not.
     
  19. James Sawyer

    James Sawyer ArboristSite Operative

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    The sap is starting to run a little and the full comp chain...maybe the Gulet is getting full and stopping the chain...it just didn't seem right. The tree were leaners so they went early...just worried about a Barber Chair or splitting up the trunk. I'll just cut firewood with this MS362 for now use one of my other saws to fall with. I just don't like standing there as the tree going tryin to cut up to the hinge with a saw that won't saw.
     
  20. grizz55chev

    grizz55chev Tree Freak

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    Anything less than 150 is unacceptable.
     
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