Kohler sv720 start problem

Discussion in 'Mechanic and Repair' started by hotrodsnapper, Jul 15, 2008.

  1. hotrodsnapper

    hotrodsnapper LawnSite Member
    Messages: 85

    Hello lawnsite!

    Long time, no post.

    I picked up a Toro GT 2100 a couple of months ago as a refurb from HD. It beats the old snapper hands down, but I've been having some starting problems. Please note that it is under warranty, so I willl be having someone fix it, but I'd like your thoughts on the "root cause" of the trouble because I want to make sure that I don't spend a lot of time letting the shop bandaid up the secondary problems.

    Here's what is going on. Even when I first got it, the starter struggled to turn the engine over. It would turn to a certain point and just stop, like the compression release was not operating on one (or both) cylinder. Up until the other day, I would just try a couple of times and it would start after 3 or 4 tries. (I mean engaging the starter until it stopped, then release the key and do it again). Once it got started it runs perfectly. I assumed the battery was getting a little weak, so I was not too worried about it.

    Yesterday I was using it and turned it off. When I went back to restart it, it did the same thing where the starter would stop whenever it hit the compression stroke. After trying to crank it eight or ten times, the starter stopped working. I get a click from under the seat (solenoid, I guess), but no action from the starter.

    I grabbed a pair of jumper cables and hooked them up to my car, which has a near-new battery and a perfect charging system. I hooked up to a good ground on the engine and hit the + cable on the starter terminal. The starter turned, but it stilldidn't have enough power to get past the compression stroke.

    So it looks like the starter is fried and the contacts on the solenoid are burnt. I sould be able to get these under warranty, but here's my concern: I would not have needed to work the starter and solenoid so hard if the motor were not so darn hard to turn over. So my question is; Is there a easy way to verify that the compression release is operating, without opening the crankcase? I would imagine that you could pop a valve cover and look for the exhaust (or intake?) valve to open a little during the compression stroke, but I'm totally unfamiliar with Kohlers.

    I just downloaded the service manual and will be checking that out shortly.

    Thanks for any help, and sorry for the long post!
  2. Phil G

    Phil G LawnSite Senior Member
    Messages: 844

    Just a thought before you start tearing into it:) Have you checked all the wiring? Work from the battery to the starter/solenoid and the earth cable from the battery. I don't know your machine but some have two earth straps, battery to chassis and chassis to engine when the engine is rubber mounted. I've seen many turning slow because of a bad/rusty/corroded connection causing a voltage drop. Only takes a few minuets and it'll do no harm to have these clean anyway. Could well be the starter motor but, anyways go 'line of least resistance'
    atb Phil

    Better still, remove and clean all contacts including the battery terminals, wire brush and when clean and refitted cover with a smear of grease
  3. hotrodsnapper

    hotrodsnapper LawnSite Member
    Messages: 85

    Thanks for the reply, Phil!

    I'll check the connections, but if that were causing the trouble, would it not have worked with jumper cables at the engine block and starter terminals? I figured doing that eliminated any grounding/rust issues.

    Just for everyone's informations, I have yet to see any rust on this machine. It's last year's model with about 40 hours. It's new other than that and the finish being a little faded from sitting in the sun at HD for a few months.
  4. Phil G

    Phil G LawnSite Senior Member
    Messages: 844

    If you earthed onto you mower engine block and touched the engine side of the solenoid, then yes it should have spun over. Be careful when doing it like this, sparks fly everywhere and small risk to other electrical components.
    Then's the time to have the starter checked out
    Good luck Phil
  5. VegetiveSteam

    VegetiveSteam LawnSite Senior Member
    Messages: 296

    SV twin cylinder engines have no compression release so you might want to look for a different problem. The other thing and pretty important is unless they put a brand new straight out of the box engine on a refurbished frame that engine has no warranty through Kohler. HD never tells you that part but the engine is warranted to the original purchaser only and when that person returned it to HD and HD put it out as a discounted unit the warranty is done.
  6. Rearwin

    Rearwin LawnSite Member
    Messages: 1

    I've been dealing with the same exact problem! I'm presently in discussion with the company who sold me the tractor. Here's what I've discovered.
    I removed the starter, thinking it must have burned something and failed. When I searched for a replacement, the specs of all the replacements were,`12v, ccw rotation, 10 tooth. As I compared the one I removed, I realized it was 9 tooth. This would have THICKER teeth, needing to be FORCED into the ring gear, and requiring great effort to turn to start! My ring gear shows damage from the mismatch, also! The Co. says their TORO specs call for for 9 teeth. The evidence shows that to be incorrect. Check yours for the same mistake.

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