I'm looking for the head tension for a Kohler 14hp engine. I think it's a cv14

A couple of things to look for ....
The STX38 has a 12.5HP Kohler Command engine, being model CV12.5. Basically just a "throttle restricted" version of the CV14 which is 14HP, and the CV15 and CV16. All were notorious for experiencing Ignition Module problems which may manifest as any (or more) of the following ...
Erratic running & backfiring due to ignition timing out of control.
Popping back thru intake (also due to timing all over the place).
Engine cutting out after start-up.
A switched-on John Deere dealership will know about this and likely keep a replacement ignition module on the shelf, coz it's a good quick fix.
Another cause for your problem may simply be a fuel problem. 01. Look for inoperative Afterfire Solenoid (on the bottom of the carby bowl). Put your hand on it and switch the key on & off .. you should feel/hear the solenoid click.
02. Blocked fuel line filter.
03. Dirt, or debris, or water/moisture in the carburettor.

Hope this helps.

(ignition module is both the ignition coil AND the electronic trigger module integrated into a single sealed, un-serviceable unit)

should be all right just check shaft length and diameter

Fuel solenoid, filter blocked, pump, carb leak check those

from what i can see it has a 14hp kohler engine

fuel issue: filter, pump, carburetor.Hope this helped Tim

I had this issue on my 14hp kohler and it was the ignition module. Would run until it heated up then shut down.

ususally it is the tensione just has to much give it will nbeed to be rreplaced

I have a Ford LGT with a 14 hp Kohler K321AS engine. Go to Kohler.com and download the service manual for the K321 engine. The manual covers all of the K type engines and gives diagrams and details of all the different types of ignition and electrical systems. It is free. JS

sometimes there is a adjustment screw that you can turn just like a car.CAREFUL NOT TO TURN TO MUCH.to burn lean or rich.also you might want to change the fuel and air filter's first,then try to adjust.

Perhaps you would enjoy the entire service manual. Here it is: http://www.asberry.net/files/TP-2379.pdf