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gr-made

718H with low compression?

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gr-made
Hello Everyone: I am having problems getting my 718H to start. It has a single cylinder 18hp Kohler (K361QS). It quit running last fall and I did not have the time to look into it. It is getting spark and fuel. I just got a new compression tester from Harbor Freight today in the mail so I thought I would see what the tractor read. It had somewhere between 20 and 25 pounds of pressure. My question to all of you, is my engine shot? If so what is the best way to handle it, rebuild or buy a short block? What is the value of this engine if any if it is shot and I buy a short block? Someone told me a lot of people like the torque you get out of the single 18. I really love the tractor and I feel the unit has a lot of life left in her but I know just enough mechanically to be dangerous. Thanks, GR-MADE

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B_WALLY_
Remove the head and check for a burnt valve. I recently had this problem on a 12hp Kohler. I had a used valve, just lapped it in and presto, runs like a champ.

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stevejj56
You would be very lucky if you could find a short-block. Most of the 18HP engines didn't hold up very well. They were a test engine really,the guys at Kohler didn't have much to say about them. You would probibly have to replace it with a 16 hp engine. Like B WALLY said its probibly a burnt valve. Rings wearing out happens gradually.

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JeffH
Ron, is right - it is probably just the release valve giving you poor compression. Was the tractor deteriorating in performance, smokeing, etc? Check the release valve first.

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dlcentral
THAT'S the problem,,, the Harb.Frt.tool!lol! Before you take the whole thing apart,check the valve clearances.The box behind the carb is where you check it from.And true those motors are obsolete now.Any older K series or newer Magnum series will fit.

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carter
GR-MADE Most of the Kohler singles have a compression release that lifts the inlet valve at cranking speeds. You won't get more than about 25# on the compression gage on a good engine. You might have valve problems but I wouldn't race into tearing it down until you are certain that it isn't something as simple as a spark plug. If you haven't put in a new plug I'd sure try that before you go any farther. Just because you have spark to the plug doesn't mean it is firing in the cylinder. Ron

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Eddie
keep your old motor and rebuild it. Take it apart hone the cylinders and bye new piston rings. Also did you do a wet compression test. That is when you take a little bit of oil and put it in the cylinder then do your compression test again.

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Eddie
When you did a compression test you got a reading. But did you do a wet compression test? That is when you poor a little bit of oil in your cylinder and re take the test. If the compression test goes up then it's your piston rings, and the reason why that problem was diagnoised was because the oil fills in the gap between the piston and the ring gap, also the cylinder wall. If your compression test stays the same then it would be your valves. So re take your test and do a wet compression test then see what your problem is. I wrote back to you because I never finished because I was in shop and had to get back yo work. But do that test and see what happens.

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