I have a kohler courage pro 26hp. Model # sv735-0016. The exhaust tube with glow red at half throttle up to full throttle under no load. I've checked for intake leaks and replaced the carburetor with a new oem replacement. I've pulled both heads and replaced the headgaskets and relapped the valves. Put it all back together and set the valves at .004&.006 intake/exhaust. I've checked the shear key several times. I've pulled the muffler as well and let it run with just the tubes. I'm at a loss for what could be causing this!! Any help???????

I have determined the oil level switch is bad. Oil has been changed and is at the correct level. I can unplug the switch and it runs and gens. I can find no manuals or service support other than a displayed IPL, on this other than a distributor in North Carolina who contacted us for a warranty claim as this is a brand new unit from a local big box store. Correspondence has been via email only, even though I provided my contact phone and can not source or been provided with one for them, I requested service manuals as well as tech support as this switch is internal to the engine and requires seperating the gen from the engine which is not routine..............how fast should I run?