1. Welcome Hearth.com Guests and Visitors - Please enjoy our forums!
    Hearth.com GOLD Sponsors who help bring the site content to you:
    Hearthstone Soapstone and Cast-Iron stoves( Wood, Gas or Pellet Stoves and Inserts)

Big chainsaw troubles..... help needed

Post in 'The Gear' started by hemlock, Apr 10, 2013.

  1. hemlock

    hemlock Feeling the Heat

    Joined:
    May 6, 2009
    Messages:
    455
    Loc:
    east coast canada
    Hello,
    It looks like my Husky 365 just bit the dust, and I can't figure out what happened. It was cutting along just fine, then sputtered, rattled and died. Tried to pull it over, and there was nothing. The compression is completely gone (gage reads almost zero). It was not straight gassed. The only thing I can think of is an air leak some place, but it did not feel or sound lean. What else might have caused this? Any help would be great. I think I'm about to cry. Thanks

    Helpful Sponsor Ads!





  2. arngnick

    arngnick Member

    Joined:
    Feb 15, 2013
    Messages:
    245
    Loc:
    Mansfield, PA
    How new is the saw? I had a buddy that the same thing happened to him during the first year of owning the new saw. The dealer blamed it on old gas with ethanol in it. I think the reluctantly covered it onder warranty.
  3. Joful

    Joful Minister of Fire

    Joined:
    Mar 7, 2012
    Messages:
    6,455
    Loc:
    Philadelphia
    Rattle? No compression? sounds like a broken connecting rod.
  4. hemlock

    hemlock Feeling the Heat

    Joined:
    May 6, 2009
    Messages:
    455
    Loc:
    east coast canada
    Thats what I thought - but when I removed the plug and pulled it over, the piston was moving.
  5. Nixon

    Nixon Minister of Fire

    Joined:
    Aug 6, 2008
    Messages:
    698
    Loc:
    West Sunbury ,Pa.
    Pull the muffler and see what the piston looks like. You may have torn an intake boot ,or lost a crankcase seal .
    smokinj likes this.
  6. MasterMech

    MasterMech Guest

    +1 on pull the muffler. Broken ring? Husky is still a single ring design no?

    Check the decomp valve?
  7. hemlock

    hemlock Feeling the Heat

    Joined:
    May 6, 2009
    Messages:
    455
    Loc:
    east coast canada
    Pulled off the cylinder, and everything looks pretty good. Is it likely a crankcase seal?
  8. Joful

    Joful Minister of Fire

    Joined:
    Mar 7, 2012
    Messages:
    6,455
    Loc:
    Philadelphia
    Just so we're not making any wrong assumptions, how exactly did you test compression? Be specific.
  9. MasterMech

    MasterMech Guest

  10. hemlock

    hemlock Feeling the Heat

    Joined:
    May 6, 2009
    Messages:
    455
    Loc:
    east coast canada
    With a gauge. Pulled it over a few times. It hardly blew anything.
    Master Mech - I'll check the decomp.
  11. HittinSteel

    HittinSteel Minister of Fire

    Joined:
    Aug 11, 2008
    Messages:
    1,587
    Loc:
    Northeastern Ohio
    Good news on the piston! Now you just have to find where its getting air.

    Isn't compression made above the intake and exhaust ports? If so, what else could it be besides decomp, spark plug hole, cracked cylinder, stuck ring, ??????

    I had the same situation on a saw I compression tested for a guy. Showed nothing on the gauge. Pulled the muffler and the piston and rings were in great shape. It stumped me (and he didn't leave the saw with me for further investigation).
  12. thewoodlands

    thewoodlands Minister of Fire

    Joined:
    Aug 25, 2009
    Messages:
    10,825
    How's your spark splug, did it blow out , might need a heli coil.
  13. Joful

    Joful Minister of Fire

    Joined:
    Mar 7, 2012
    Messages:
    6,455
    Loc:
    Philadelphia
    That's why I asked how he's measuring compression. If it's not putting any compression on the guage, the spark plug is out of the equation.

    If the decomp valve is good, then it's time to pull the jug!
    smokinj likes this.
  14. smokinj

    smokinj Minister of Fire

    Joined:
    Aug 11, 2008
    Messages:
    15,972
    Loc:
    Anderson, Indiana
    "The rattle" Small sound Rings broke Big sound crank?????? Either way air leak is not going to be a rattle. Iam with Joful time to pull the head and hope its rings.
  15. cnice_37

    cnice_37 Member

    Joined:
    Mar 24, 2011
    Messages:
    55
    Loc:
    Assonet MA
    I'd check to see if the ring moves by using a small screwdriver and pushing it through the open exhaust port (you removed muffler already.) My guess is its stuck, pretty common on these saws I believe.
  16. Fiziksgeek

    Fiziksgeek Member

    Joined:
    Jan 3, 2012
    Messages:
    108
    Loc:
    Oxford, CT
    My first thought would have been a lean seizure.
  17. hemlock

    hemlock Feeling the Heat

    Joined:
    May 6, 2009
    Messages:
    455
    Loc:
    east coast canada
    Put the cylinder back on and checked the decomp valve and it is also good. Guess I'm bringing it to the dealer. It makes no sense at all. Everthing that would cause a compression issue checks out, but it has 0 psi. I'm thinking something else is going on. This is out there, but could the flywheel be turning on the crank, and with the plug/gauge in, it creats just enough back pressure to cause the flywheel to turn on the crank, but with the plug/gauge out, it allows the piston to turn over, due to no back pressure? It's a stretch, but it all makes no sense otherwise.
  18. MasterMech

    MasterMech Guest

    Pretty easy to yank the flywheel and look for a sheared key. Or just mark it and pull it over, recheck the marks.
  19. Nixon

    Nixon Minister of Fire

    Joined:
    Aug 6, 2008
    Messages:
    698
    Loc:
    West Sunbury ,Pa.
    Is that going to address the 0 compression ? Seems like a real mystery ..... 0 compression ,good decomp and plug , good P/C and rings .
  20. MasterMech

    MasterMech Guest

    But Hemlock makes a good point that the flywheel could just be spinning on it's taper. If it ain't rings, piston, cyl, decomp or spark plug, I'm open to slightly more exotic theories. ;hm
    Nixon likes this.
  21. cnice_37

    cnice_37 Member

    Joined:
    Mar 24, 2011
    Messages:
    55
    Loc:
    Assonet MA
    Check the ring!!
  22. hemlock

    hemlock Feeling the Heat

    Joined:
    May 6, 2009
    Messages:
    455
    Loc:
    east coast canada
    Thats what it is. I feel like an idiot. I marked the flywheel to the nut, gave it a pull as though starting, and the flywheel is spinning on the crank. When you pull it over slowly or remove the plug, it grabs the crank and turns. Thing is, is this good or bad - and can it be fixed? Does anyone know the torque spec for the nut?
  23. basod

    basod Minister of Fire

    Joined:
    Sep 11, 2009
    Messages:
    937
    Loc:
    Mount Cheaha Alabama
    Is the flywheel keyed to the shaft? If not the timing mark will matter.
    If you figure that out remove the plug and use a piece of clothesline stick down in the plug hole this will prevent engine turning over during tightening

    What size is the nut? rather the shaft thread(it's somewhere in the 1/2,9/16,5/8,3/4- ball bark standard size. Just close doesn't matter if metric
    I'd assume it's fine thread as well. could be anywhere from 90-200ft-lbs (though probably newton-meters)

    Definitely use some red(higher temp) threadlocker or similar when reinstalling
  24. Joful

    Joful Minister of Fire

    Joined:
    Mar 7, 2012
    Messages:
    6,455
    Loc:
    Philadelphia
    Definitely ignore anyone's home-grown ideas, and definitely follow the procedure in the shop manual.
  25. hemlock

    hemlock Feeling the Heat

    Joined:
    May 6, 2009
    Messages:
    455
    Loc:
    east coast canada
    I put the flywheel back on (you can still see where the key was), and torqued it down, and it fired up. My question now is - is the key critical for power transmission, or is it strictly for timing? My guess would be that being a tapered shaft, that the key is primarily for timing but still am not certain. The key was cast right into the flywheel.

Share This Page