Yep, this red hot exhaust thing has been brought up before. It alarmed me the first time I saw mine in the dark cave of a garage I had. Don't worry about it, some guys think it is because of being too lean but a properly jetted machine will do the same thing. As far as the 4 stroke kick back on the kick-starter, I have a story when I was 8yrs old and blew up my yz 80. I was flat out on a logging road near my grandfathers house when she let go- I left skid marks from the tire locking up for about 30 yards. Being so young I really did not know what happend to the engine so I flipped the kick starter out and gave it a hard kick. The starter went down half way and stoped (my foot hurt for weeks after that)!