I have a generac generator xp8000e I converted to tri fuel. They had to drill out the carb for clearance reasons. Right now I am running it on propane and to get it to run smooth, I have to adjust it to 4600 rpms. I understand the optimun rpm is 3600. when I tri to run it at 3600 it sputters and backfires. I am worried at 4600 the engine will be running too hot. I have never had a generator before but I noticed the exhaust got a little red after 5 minutes. I have a leaf blower that gets hot but that is normal for that. Is what I'm seeing normal? Am I running the risk of it burning up at 4600?