help please, Kohler 27 hp losing power and running rough

Discussion in 'Mechanic and Repair' started by runthetableandy, Apr 8, 2011.

  1. runthetableandy

    runthetableandy LawnSite Member
    Messages: 21

    Ok, I'm going to try to give as much background information as possible. It's a Cub Cadet Tank with a 27 hp Kohler engine with less than 600 hours. It has never had any issues with the engine running bad. So I started my mower today and mowed my yard (about 20min worth of mowing) it started and ran perfect. Soon as I was done with my yard, without even cutting the blades off I drove across the street to mow my neighbors yard, everything is fine until right after I mow a really steep ditch. The ditch was about 35-40 degrees, it was completely dry and if it was any steeper the back tires would have started to slide. Just one pass down the ditch, which is about 75ft long I come back mowing down the flat part of the yard full speed, very thin grass partly dead from winter still, so it shouldn't have any trouble cutting this at full speed and all of a sudden it feels like the throttle lever is being pulled back down to idle. The rpms just start falling for no apparent reason. So I stop, look around, everything looks fine. While I'm stopped the rpms go back up to normal so I try to take off again, soon as I try to go forward the rpms start falling again. I did this a few times with the same result. So I disengaged the blades and started driving back across the street to my house. Even with the blades disengaged when I tryed to go full speed forward the rpms would fall. So I lower the throttle lever and drive home at about half speed. Now the rpms are going up and down up and down as I'm driving home. I get home and try to bring the rpms down to idle and it starts to die, so I raise it up a little and it will idle a little higher than normal but the rpms are still going up and down constantly. So I shut it off for about an hour and start it back up and it runs fine, full speed full throttle no issues at all. So I go back to the yard across the street and start mowing (not on the ditch, all flat ground now) and in less than 10min and the rpms start dropping out of nowhere again. The rpms are now going up and down constantly again while I go home. I shut it off let it cool off a little, pull the plugs, and they look fine, no black on them at all. I changed the oil last week so I check the oil and it was over filled. Looking at the dipstick theres the hash marks and above that it says full and the oil level was above the full! So i drain the oil until its exactly in the middle of the hash marks. Start it up and the rpms are still going up and down and won't idle low where it normally does without shutting off.
    My first thought was that mowing on the steep ditch with over filled oil might have something to do with it, but I don't know how that would cause the issues I'm having because I've mowed steep ditches before, but not with the over filled oil. Does anyone have any ideas of what might be wrong or get me pointed in the right direction?

    Thanks in advance for any help, Andy
  2. runthetableandy

    runthetableandy LawnSite Member
    Messages: 21

    Two more things:
    1) My dad seems to think it might be bad gas. I don't think thats right, I filled it up at a Shell station last week and mowed one yard after I filled it up and didn't have issues till today. If bad gas/ water in gas is a possibility would some kind of fuel treatment be worth trying.

    2) I was looking on Kohlers web site and found this under troubleshooting section:

    Runs Rough on Low & Will Not Accelerate

    * Spark plug gap incorrect -----don't think its this
    * Engine not properly warmed up -----definitely no
    * Running out of fuel ----- fuel filter looks fine
    * Low idle set too low (below 1000 RPM) ----- possibly, I'll check tomorrow morning
    * Low idle fuel setting too lean -----???
    * Electric clutch dragging ---- ???
    * Parasitic load on power take-off (PTO) shafts ----- ????
    * Crankshaft end play zeroed by drive -----???

    Stops on High Idle

    * Running out of fuel
    * Running out of oil in crankcase
    * Carburetor solenoid malfunctioning ----<---- I saw people mentioning this in other threads I have no Idea what this is
    * Key switch malfunctioning ----<---- My key switch is going bad...
    * Safety interlocks malfunctioning
    * Spark plug lead loose
    * Fuse blown in control box
    * Carburetor out of adjustment
    * LPG regulator malfunctioning
    * Loss of vacuum to LPG regulator
    * Tight drive belt causing crankshaft bearing to seize"
  3. scagwildcat

    scagwildcat LawnSite Senior Member
    from nw. ct.
    Messages: 507

    i dont know if this could be the problem, but with the engine angled the way it was for a long time, could one cylinder not get enough oil? if one cylinder is toast you would see the same problems......
  4. weapons of grass destruction

    weapons of grass destruction LawnSite Member
    Messages: 228

    Is this the first time you used the mower this season?
    Was there gas in there before you filled it up.
    If so it might be the carb thats dirty.
    solenoid is on the back of carb it has 2 wires going to it.
    one should be connected to the carb.
    another thing the choke might be stuck.
  5. runthetableandy

    runthetableandy LawnSite Member
    Messages: 21

    I've been using it for the past 4 weeks this season. There was about half a tank of gas in there from last year that I had Stabil in over winter. I ran that gas out the first two or three weeks this season and it did fine and filled it up last week for the first time this year. I'll go check if the choke is getting stuck and try to locate the solenoid and see if the wires are connected.
  6. runthetableandy

    runthetableandy LawnSite Member
    Messages: 21

    Ok I checked the choke and its working properly, opening and closing with the lever. It started right up no problem idled smooth at about 930rpm right after starting, after about a minute it had warmed up a little and was idling around 1080rpm. Seems fine at full throttle and driving around.

    Heres some pictures of the what I think is the solenoid yall are talking about, the wires seem to be connected:

    Pic one zoomed out for reference:

    Pic two zoomed in under the Kohler Command Sticker to under the carb:

    Pic three different angle:
  7. weapons of grass destruction

    weapons of grass destruction LawnSite Member
    Messages: 228

    Yes that is it.
    Take a wrench to the solenoid.
    and make sure it is working properly.
    touch the wires where they go while the solenoid is out.
    and see if moves.
  8. runthetableandy

    runthetableandy LawnSite Member
    Messages: 21

    Ok so I just tried to mow with it and within 5min it was acting up so I took a video (turn your sound up):

    I'm about to go take off the solenoid and make sure it works, will update after that.
  9. runthetableandy

    runthetableandy LawnSite Member
    Messages: 21

    Well I started to take the solenoid off and gas started coming out, and I don't know if thats normal or not but the shop closes at 12 on Saturdays so I went and took it to them. I won't be able to pick it up till next Friday, so when get it back and I find out whats wrong I'll post it on here.
  10. Genlandscape

    Genlandscape LawnSite Member
    Messages: 185

    Looks like your air cleaner weas bouncing around. check the screws in the governor plate. I have had a screw back out due to vibration and this will cause the governor th fail, causing the throttle surge. I've got one of the same engine that will not stay running, and another with an electrical problem. I hate these Kohlers, p.o.s!!!

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