Help!!! 27 Hp Kohler Smoking

Discussion in 'Mechanic and Repair' started by I MOW ALONE, Nov 2, 2005.

  1. I MOW ALONE

    I MOW ALONE LawnSite Bronze Member
    Posts: 1,912

    Hey guys need a little :help:

    I have a 27 hp Kohler that is blowing blue smoke, sometimes its fine and others it will smoke quite a bit on start up after it has been run and is warm. Sometimes, it will smoke on start up cold too. Just the other day I started it and it smoked really bad especially when you give it throttle or back off the throttle. If you run it wide open it clears up, and does not smoke at all.

    I forgot to add this engine has 160 hours on it. Oil has been changed every 30 to 40 hours. Checked oil level and it was a little low, so I added a little to bring it up to the full mark. I do not have too much oil in it, I am sure. Pulled the plugs, one was wet with oil slightly, and black carbon, the other plug looked perfect. Did a compression test today, the one with oil in it was 125 psi, the other one was 135 psi. I think that is good.

    What should I check next?:confused: Thanks
     
  2. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    If it only has 160 hours is it still under warranty ? I would take it to a dealer and let them perform a cylinder leakdown test, Kohler has a head gasket problem and it could be leaking at the oil return passage. This is where I've been finding the problem. Warranty will cover such repair.
     
  3. I MOW ALONE

    I MOW ALONE LawnSite Bronze Member
    Posts: 1,912

    The lawn mower is a 1996, when I bought it, it had a 22 hp Kohler on it that needed a valve job, so instead of spending the money on an engine with 1000 hours on it, I figured I would buy a brand new one, and decided to go with a little more hp. I bought this engine off of e-bay, the engine was brand new, but did not come with warranty. So I am stuck on my own. If the head gasket was bad, wouldn't the compression be low?
    Thanks for repling.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    It would depend on how bad the gasket is leaking, Kohler doesn't recommend a compression test due to the compression release just a leakdown test.
    I have had them come in smoking and have no sign of power loss. The first 5 or 6 that came in I did perform the leakdown test but after that I just pull the plugs if one is oil carboned I just rip that side off and thats what I find.
    I would suggest finding a shop that can do a leakdown test just to make sure, Then you can decide if you want to do the job or them.
     
  5. I MOW ALONE

    I MOW ALONE LawnSite Bronze Member
    Posts: 1,912

    i will have the leak down test done. so you are pretty sure it sounds like a head gasket going bad.
     
  6. I MOW ALONE

    I MOW ALONE LawnSite Bronze Member
    Posts: 1,912

    also wanted to ask. when you do the leak down test does the cylinder have to be at tdc on compression stroke. thank's
     
  7. Soupy

    Soupy LawnSite Gold Member
    Posts: 3,125

    Mine is doing something similar, but it onle happens every great once in awhile. This motor also sputters when I shut it off sometimes, but not very often. I think it is when it's warm, because it hasn't done it for awhile now that we have cooler weather. I always let the engine idle for 30-60 seconds before turning it off. This motor has about 160 hours on it as well. It's on a 05Hustler. Oil changed every 40 hours except for the break in period where I changed it more frequent. I use the both air filters on the donaldson setup.
     
  8. I MOW ALONE

    I MOW ALONE LawnSite Bronze Member
    Posts: 1,912

    also if it was a head gasket wouldnt it be smoking all the time. or no
     
  9. Brianslawn

    Brianslawn LawnSite Silver Member
    Posts: 2,004

    yeap. and 125 is just a little low for a kohler. should be 135-160 depending on model and spec#. if its not head gasket, then rings. how quick does it go through oil. also you sure it was brand new or real clean rebuilt? i dont trust flea-bay merch.
     
  10. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,022

    It would depend on the expansion and contraction of the aluminum as to how bad or when it would go to smoking. The leak down test must be performed at TDC compression stroke as brian said but the flywheel must be pinned so it doesn't rotate when the air is applied. This test will not only check the gasket but the rings and valves also, So if it is indeed rings you will find out.
    I would still bet a gasket over rings since this has been a on going problem for a couple years now. They did have some breather and reed issues also but they have seemed to have gotton them taken care of.
     

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