okay so here's the deal I have a 6.5 harbor freight greyhound clone engine that has served me very well over the last few months. I have remove the governor and install it on the lightweight aluminum flywheel with timing advance. I had a home made exhaust on it consisting of a 16 inch long 1 inch diameter pipe with a briggs and stratton sausage muffler on the end. I took it out yesterday and this thing was writing like an absolute dream I mean it was so responsive it was amazing. no vibration no nothing it was absolute butter. that was with the old stock iron flywheel. today I install the honda aluminum flywheel with the timing advance and it seems as if the engine does not have to get up and go that it did before and it's running very choppy and it vibrates a lot. also the engine seems to be getting very very hot very quickly. I took some readings with my infrared thermometer and the block itself was reading right around 120 which actually seems fine even though I only wrote it for about 5 minutes. however the cylinder head and cooling fans on the engine block were reading 200 + like 210 or 220 and my exhaust header pipe was reading 420 degrees! this seems a bit excessive but honestly I don't know if it should be getting this hot because I never really had a reason to check the temperature before today. the only reason I checked it today because I went to pull the spark plug boot off and I burned my hand on the valve cover. right now the engine has been at rest for well over 10 minutes in the valve covers still reading 108 degrees. does this sound about right or is my engine getting too hot. also if it is getting too hot what could be the cause? I cant imagine the flywheel with the 4 degree timing advance would cause this much of a dramatic change in performance at least not in a negative way. the engine is completely stock with governor removal and aluminum flywheel, other than that it's exactly how I came from the store. I am 170 pounds and it's on an old style doodlebug frame. please let me know because I would really like to ride this tomorrow morning but I don't want to ruin it. also if my chain is too tight will it cause my engine to excelerate slower than normal? thanks guys I really appreciate any info you may be able to give me a really need to solve this problem.