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Kohler KT17 Series II rebuild?


KeithCT

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I have a 17GTH-L tractor with a Kohler KT17-II engine. Last fall it blew the rear-facing crankshaft seal. It sat over the winter, and then this spring I pulled the engine and replaced the seal and the breather. 2 cuttings later, it blew the seal again. Thinking that I had installed the seal incorrectly, I pulled the engine again and very carefully put another seal in.

I put everything back together and realized that it is massively blowing exhaust out the oil filler tube when I take the cap off. I'm assuming the rings are shot.

If I were to rebuild the engine, how far would I probably have to go? Have the cylinders bored out? Oversize rings? Do I need new pistons too if I do that? Will the crankshaft possibly need work too? Not sure what I'm getting myself into here.

-Keith

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You will need new pistons if it is bored. You will not know if it needs bored or crank turned until check with a micrometer. NAPA can do the machining and check the spec. or at least they can here.

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I've had about 20 or so of these KT/Magnum twins, typically, the cylinders don't wear much.

I've had much success replacing rings, as long as the end gap is within spec, I run them.

I've saved many of these engines, without spending a ton on a rebuild, or a ton on a new engine.

You may need valve work though, as the guides / valves do wear, and are not adjustable.

Typically the crank journals and rods are fine if you don't hear any knocking in the engine, as they're fully pressurized at about 50 PSI, they hardly wear at all. I have had only 1 where the crank was trashed. The rest were all within spec.

Despite what many people say, these engines are indestructible provided they are kept clean, and the governor gear isn't overheated causing fatigue.

I would replace the governor gear for sure.

I love picking these blown engines up, as usually repairs aren't costly if you have spare parts, and typically even if the rod breaks and seizes to the journal, once cleaned with muriatic acid, is still within spec.

New aftermarket rods are available for these now on ebay for $60 each.

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Question Maxtorman; I have a KT-17 series II that runs fine with no unusual sounds but is running on one cylinder. The is NO cylinder pressure on one side. It appears I will have to completely crack open both crank case halves to get to the broken rod. Is there any advice when opening this up. It looks extensive?

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Your engine has blow by but... if you are blowing seals the breather is not working. Repair/replace the breather and run the engine for several more years.

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quote:Question Maxtorman; I have a KT-17 series II that runs fine with no unusual sounds but is running on one cylinder. The is NO cylinder pressure on one side. It appears I will have to completely crack open both crank case halves to get to the broken rod. Is there any advice when opening this up. It looks extensive?id="quote">
id="quote">

For starters, I would not run that engine until you determine the cause of no cylinder pressure. It does sound like a broken rod, (with NO cylinder pressure) but it could be a valve stuck wide open. Running the engine, at all, with a broken rod is asking for further damage from all of the debris in the oil and the rotating parts that can destroy other items.

You can check valves relatively easily by pulling the valve covers and visually inspecting the stems. You do not need to pull the engine or tin to do so, on the KT series.

If you do have to open up the engine, it can be more challenging than a single cylinder Briggs or Kohler, that is for certain. But if you have the manual and follow it, it's not impossible or overly complicated. KT and Magnum parts can be pretty pricey however. Be prepared to spend as much as or more than $5-600 for rods, pistons, gasket set, machining, misc. parts, etc.

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quote:Originally posted by MikeES

Your engine has blow by but... if you are blowing seals the breather is not working. Repair/replace the breather and run the engine for several more years.


id="quote">
id="quote">Should the breather really take care of blow-by to the point where it's blowing exhaust out the oil filler tube when the cap is off? I assume there is a limit to how much blow-by the breather can "vent".I actually replaced the breather before the second seal blew. I can double check to make sure it's installed correctly.
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