Kohler K321aqs running hot.

[chevelle70]

I have a 82, 314 John Deere that used to be my late fathers. Six years ago, I was mowing, it overheated and blew the spark plug out of the head ruining it, I got another mower and it set in the garage until last fall. After a lot of searching, I found a new head and gasket and for good measure since it had set so long, I replaced the points, condenser, carburetor, coil, ground the valve seats. This spring I start mowing and it did good for 45 minutes overheated and quit, I let it cool for an hour and it mowed for 30 minutes and quit, let it cool for another hour and was able to finish. I replaced the coil and fuel pump and added a in line filter, still the same problem. It gets so hot the muffler glows red, so thought perhaps a partially clogged muffler, so I replaced it too. The motor also when running you can see the governor arm pulling back on the throttle linkage and the motor goes from running normal to sounding like it is under an extreme binding pulling down the engine and it backfires. Any help will be greatly appreciated, I even loaded the mower up and took it to a Kohler certified shop, they charged 295.00 for me to have the same issue.
P.S. Also last fall for good measure I upgraded to HyGuard and new filter.

 

[ILENGINE]

Two questions Did you set the timing with either a timing light or a ohm meter after replacing the points and condensor. also did you replace the head bolts after removing the head and retorque them properly. The head bolts used on those were a special alloy and were a one time use. the symptom is running until hot and then loosing power and backfiring until it shuts down and then would restart and run into hot again. Since the aluminum head and the cast iron block expand and contract at different rates the improper bolts will allow the difference to cause repeated loss of compression at the head gasket.

 

[Fish]

What are the valves set at?

 

[VegetiveSteam]

Like ILENGINE mentioned, take a timing light and check the timing. Setting the points with a feeler gauge is just a starting point. Often times the point setting needs to be tweaked a bit to keep the ignition timing correct. I've seen K-series Kohlers burn a hole in the head when run out of time.

 

[chevelle70]

Two questions Did you set the timing with either a timing light or a ohm meter after replacing the points and condensor. also did you replace the head bolts after removing the head and retorque them properly. The head bolts used on those were a special alloy and were a one time use. the symptom is running until hot and then loosing power and backfiring until it shuts down and then would restart and run into hot again. Since the aluminum head and the cast iron block expand and contract at different rates the improper bolts will allow the difference to cause repeated loss of compression at the head gasket.

I only set the points with a feeler gauge, however since I purchased the parts from Amazon the Kohler Certified shop installed their points, condenser, coil, and spark plug and made all adjustments. I did reuse the old head bolts, but if the gasket was leaking would it not show on a compression test? I am getting so close to throwing in the towel an putting an B&S Intec V-twin in it,

 

[chevelle70]

What are the valves set at?

I honestly do not remember what I set them at, I think .009 intake and .018 exhaust. I do remember the keepers were a pain to reinstall.

 

[chevelle70]

Like ILENGINE mentioned, take a timing light and check the timing. Setting the points with a feeler gauge is just a starting point. Often times the point setting needs to be tweaked a bit to keep the ignition timing correct. I've seen K-series Kohlers burn a hole in the head when run out of time.

That might have been why it blew the spark plug out of the head 7 years ago. I set the points with a feeler, but the Kohler shop put their points in it since I used ones from Amazon.

 

[ILENGINE]

Just because a certifed Kohler dealer installed the points doesn't mean they went through the timing process. I wouldn't be a bit surprised if the dealer set them at .020 and forgot them. The final adjustment can be from .014-.026. With a timing light the process can be tedious. Using the meter method is time consuming.

 

[hlw49]

Running hot is usually caused by running too lean or retarted ignition timming. Also on those old cast iron engines the exhaust valve would stick when they get hot and cause it to die. When they cooled down it would unstick on it's own and run again. When it gets hot and sticks and it cools you could hear the valve pop when it unstick. Might check the compression before and after it cuts off.

 

[chevelle70]

Just because a certifed Kohler dealer installed the points doesn't mean they went through the timing process. I wouldn't be a bit surprised if the dealer set them at .020 and forgot them. The final adjustment can be from .014-.026. With a timing light the process can be tedious. Using the meter method is time consuming.

I have a dwell meter for setting the points in my Chevelle, which sets at 30 degrees. Would it be possible to just hook it up to the coil and ground it like o my car? If so how many degrees would it need to be set at.