Glowing exhaust

This is never a lean situation cause but effect of un-burned fuel still burning from too much being left over! Over jetting, flooding or blown power valves as well as lack of ign. fire power or timing too low for some reason! In some rare cases even cam timing being off! Once burning in the pipes or out side at the end it creates extra draw that sucks the engine to a lean point! If on one cylinder a rocker or spring or even a bent push rod not letting the intake work properly can be the cause! A intake sucking a little oil in changing the octane or fuels with too high of octane for your compression and timing can do this also! Its always a case of too much and adding more because it looks lean will not fix the glowing or lean problem! Remember we are talking about glow and not a real lean problem! Never mistake lean for  any thing but lean if not glowing first! We run on the edge and use A/C plugs that melt before other damage occurs! Once on the 3 cold cylinders (1, 2, and 8) we were having problems and had to realize they were going lean because of being cooler and not able to burn it all! There was no glow but just a little flame up inside the collector at each tube on those three! The culprit was too much oil placed on the K/N filter causing it to draw a bit more fuel in than air! A quick rinse solved the problem and saved a bad night !