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mbsl98

JD LT160 engine not turning over freely

mbsl98
9 years ago

I'd be interested in any opinions on the following. The Mower is a 2002 JD LT160, with Kohler Command 16hp (CV460) motor at about 375 total hours. It has been run a couple of times since its winter lay-up, with no issues as usual. Last week I went to start it and it would try to turn over the motor but only managed to turn it a small part of one revolution (based on watching the screen on top of the iengine). Sounded like low battery power, so I hooked up a good battery, with same result. Got meter and both batteries measured fully charged - tractor battery is standard small unit, 2 years old, but the jumper was a group 27 bruiser, fully charged, Next, I jumped the starter, around the solenoid, with same result - not enough juice to spin it over. I pulled the spark plug, and it then spins great so cylinder not full of fuel, etc. and hydro-locking. Plug back in and no spin again. Finally, I put the plug only partly in, leaving it quite loose, plugged in wire, and hit key. It spun and fired fine, with the loose plug allowing blow-by. After a couple of minutes, I tightened plug properly, and it started again just fine and has continued to start properly since. My conclusion is that it had a problem with the compression release mechanics getting hung up in some way. Unfortunately, I know nothing about how that release system works, or if there are other potential sources of the problem. Any maintenance I should do to prevent this again? This is an OHV design with hydraulic lifters, I believe, and it has never had any service like valve adjustments. All thoughts much appreciated.

Comments (4)

  • mownie
    9 years ago

    The only maintenance to do with hydraulic lifters is to perform regular oil changes. Nothing to adjust regarding the actual hydraulic lifters or valves.
    Oil changes should be done at 50 hour intervals, or annually if less than 50 hours use in a season.
    Change the oil as the last thing you do at the end of the season, before winter layup.
    You should always have fresh, clean oil in the engine for storage over winter.
    After changing the oil, run the engine for 5 or 10 minutes, then shut down the engine and wait for spring before starting it again.
    It is possible that the ACR stuck in the run position the last time you used the engine, but I'm at a loss to say how it could have started working again.

  • mbsl98
    Original Author
    9 years ago

    The same engine start / hard turning over issue is still occurring after the machine sits overnight. I have now discovered that if I keep hitting the starter a number of times, it will sometimes come to life and spin freely/start fine. Each try would produce just a partial turn of motor, until the one try when it spins fine. I have bypassed the key switch and solenoid by jumping directly to the starter and get the same effects as just using key start. Clearly there is lots of battery power, and I would think I have eliminated all of the high resistance points up to the starter itself. question: Could this be a form of starter failure instead of something to do with the compression release?

  • tomplum
    9 years ago

    Yes, you will get an occasional starter that is tired on one of these. You can safely jump directly to the starter w/ a known good battery to cut out the in betweens such as grounds and connection to see if you have improvement. + starter lug + battery / - battery and momentarily ground the other - end to a spot on the engine that sparking won't ignite fuel or battery vapors.

  • mbsl98
    Original Author
    9 years ago

    Thanks Tomplum. I have bypassed the intermediate connections and gone direct to starter with no improvement. That is when I thought it might be the starter if not the compression release. My guess is that a weakening starter is more likely than a compression release issue with this engine, so it looks as if I will be taking a gamble and ordering a new starter.

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