Kohler K321aqs running hot.

[chevelle70]

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.

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.

 

[VegetiveSteam]

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.

 

[chevelle70]

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.

Thanks, I definitely will check it out.

 

[Gord Baker]

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.

 

[chevelle70]

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.

 

[Tiger Small Engine]

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.

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.

 

[chevelle70]

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.

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

 

[hlw49]

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

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]

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.

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

 

[bertsmobile1]

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.

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 .