Repair-It

Hopefully this isn't what is going on... go to like 4 minutes:
https://www.youtube.com/watch?v=Ooi4FSjfG98

Tractor was taking a long time to start, so thought it was the fuel pump/check valve in the pump. Decided to replace the pump, which is in the valve cover.

Here is the new one: When taking the old valve cover off, this happened: Valve cover bolt broke, and was coated in black for some reason. The other 3 were not.

Tried to get the broken bolt out, which failed, and it ended up just being drilled and tapped to the correct threading. Heat was applied to attempt to help extract the screw before just drilling it and tapping.

Put it back together and it ran for like 5 mins than this happened:
Rocker bolt snapped...

Apparently the valve spring got torched and deformed, and hopefully is what caused this bolt failure. The rod may have been slightly bent. Hard to tell.
Replaced spring and hardware, rod, and rocker and bolt, after successfully extracting the broken rocker bolt:
Replaced parts on left (exhaust).

Engine ran with no obvious issues so pretty sure it is fixed. Need to rebuild carb next...

This is the text that made me wonder about the kit:

This is a manufacturer substitution. Part may differ in appearance but is a functional equivalent to prior parts

https://www.amazon.com/Kohler-24-757-03 ... s=2475703s
It does seem to be sold by Kohler.

Kohler site:

• 2475702-S
  24 757 02-S
  KIT, REPAIR FLOAT
  $86.17
  
  
  2475703-S
  24 757 03-S
  KIT, REPAIR CARBURETOR
  $71.95

Briggs does the same thing. That is normal.

Here is the service manual uploaded.

Actually I uploaded another one, too. This one is for natural gas or propane. The _30 one.

This tractor model is 1693764.

No luck on idle speeds from Simplicity.

Kohler says 1,200 rpm as the low idle, which is where low speed mixture needs to be adjusted. But the machine likely has a higher idle spec and the Kohler manual says that is typically 300 rpm higher so call it 1,500.

So the approach would be something like this:
- Warm up engine
- Idle all the way down
- Set idle to 1,200 rpm
- Adjust low speed mixture (find rich, find lean, set in the middle)
- Raise idle speed to 1,500 rpm min, or possibly as high as 1,800.
- Double check that full speed setting is correct. 3,600 rpm is the engine spec but 3,400 or 3,500 may also be typical.