Could be. Maybe a difference in 2 stroke to 4 stroke? I used to race motocross in a 125 class amateur when I was like 15. Dont remember a lot about the tuning, that was Dad. I just rode.
But, after working on many cars as an entry level tech (granted, I was entry level) at three different shops, glowing exhaust is usually either late/no ignition timing, too much fuel, or clogged exhaust. At one of those shops, I worked on nothing but classic European cars. I would tune carb setups on Lotus', Jags, MGs, Triumphs, BMWs, etc all day. Too much fuel would cause the exhaust to turn red.
Two of the reasons I stated are because the fuel to continues to burn INSIDE the exhaust manifold instead of inside the combustion chamber. One by simply not completely burning all the fuel before exiting the combustion chamber and it continues to burn in the manifold (too rich), the other by having the overly rich exhaust from a cylinder due to lack of or late spark hit the hot exhaust from another cylinders exhaust and burn inside the manifold (lack of/late/poor spark). The other reason, is simply a build up of hot gasses in the system. The build up, coincidently, is usually due to a cat that has died from an overly rich running condition also (clogged exhaust).
This topic used to come up all the time on the forum for Rotary engines which I used to use when I raced RX-7s. 9 times out of 10, it was an ignition or too rich running condition causing the problem (IE - new carb setup not tuned right, new MSD igniton not wired correctly, etc)
However, Im not saying Im right. Im just saying what Ive seen.
~T.J.
