Export thread

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.

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.

What are the valves set at?

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.

ILENGINE said:

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.

Click to expand...

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,

Fish said:

What are the valves set at?

Click to expand...

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.

VegetiveSteam said:

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.

Click to expand...

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.

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.

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.

ILENGINE said:

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.

Click to expand...

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.

hlw49 said:

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.

Click to expand...

Okay, I will give the compression another try. The engine has had 2 new carbs put on it plus I remounted the old carb on it last week just to try it, it ran worse with the original carb.

If I did this correctly and this link works, check out the ignition timing starting on page 8.2. It may help.

VegetiveSteam said:

https://resources.kohler.com/power/kohler/enginesUS/pdf/tp_2379.pdf?_ga=2.39984290.1859233433.1699765057-2120003328.1699765057

If I did this correctly and this link works, check out the ignition timing starting on page 8.2. It may help.

Click to expand...

Thanks, I definitely will check it out.

Buy and install new head bolts. Torque them cold and retorque them next day. Be sure your carb is not running 'lean'. Retard timing slightly and try it.

Okay, I will try to locate then, I had to search for months before I located a head. I found a rebuilt kit that had new valves, gaskets, rings and bearings but no head bolts.

chevelle70 said:

Okay, I will try to locate then, I had to search for months before I located a head. I found a rebuilt kit that had new valves, gaskets, rings and bearings but no head bolts.

Click to expand...

Could also be an intake air leak, leaning out the air/fuel mixture. Carefully spray carburetor cleaner around intake gaskets and listen for change in engine RPM. If it changes, either up or down, you have an air leak.

Tiger Small Engine said:

Could also be an intake air leak, leaning out the air/fuel mixture. Carefully spray carburetor cleaner around intake gaskets and listen for change in engine RPM. If it changes, either up or down, you have an air leak.

Click to expand...

Okay, will give it a try. I doubt that's it, when it gets hot and dies it will not fire off even on ether, I only know of loss of compression or ignition firing that would do it. I just do not know why it would lose compression when hot. Everything in the ignition system has been replaced twice and still the problem persists. I am almost to the point of pulling the engine and putting an INTEC 22hp V-twin in it. I know it would be a lot of work, but I have almost put that much wok into this old K321

chevelle70 said:

Okay, will give it a try. I doubt that's it, when it gets hot and dies it will not fire off even on ether, I only know of loss of compression or ignition firing that would do it. I just do not know why it would lose compression when hot. Everything in the ignition system has been replaced twice and still the problem persists. I am almost to the point of pulling the engine and putting an INTEC 22hp V-twin in it. I know it would be a lot of work, but I have almost put that much wok into this old K321

Click to expand...

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.

hlw49 said:

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.

Click to expand...

Okay, definitely need to check that I never checked compression hot,

hlw49 said:

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.

Click to expand...

You might like to rethink that again.
Yes running lean will cause overheating
Over advancing the engine causes it to run hot because the burned charge is inside the engine for longer thus more time to transfer heat
and of course too much advance can lead to piston failure
Now over retarding does not cause the engine to run hotter because the charge is inside the engine for less time so less heat transfer
However it does make the exhaust system run significantly hotter and as many mechanics use exhaust heat as a measure of engine heat they mistake a hotter exhaust to mean a hotter engine which is not the case .
Neither are particularly good & I hate to nit pick but this is the internet so answers will remain forever so need to be technically correct where ever possible .

Overly retarded timing reduces power and causes high exhaust temperatures, making exhaust manifolds glow red as the heat that the engine failed to convert into energy goes out of the exhaust, often with the fuel still burning. He was complaining about the muffler glowing red. Just that retarted ignition will cause the exhaust system to run hot ie the exhaust valve and muffler area. Thus said neither overly advanced or retarted ignition timming is good.

A mouse nest is inhibiting air flow across the head .

You lapped the valves and didn't clean the compound away good enough ? If that happens they will need rings within 30 min. of operation .

Timing can be checked with a helper to crank . With the plug out and grounded and your thumb/finger pressing on the spark plug , hole helper cranks and you'll see spark and your thumb or finger will be blown of the hole at exactly the same time .