I have a 2001 300ex, and today i went out to my garage because ive been keeping it in there for the winter. Every week i go out and start it and let it warm up just to keep maintanence on it. I sprayed some PB Blaster penetrating oil on the whole pipe, like 3 weeks ago to bring back the black color. Well today when i went out to start it, I let t warm up then held it at a high rev for a lil bit and the head pipe started turning fire red and sparking. Is this becuz of the stuf i spyaed on it or is t becaus e it was reved to long? Please help.
Thanx

 

i think it might be from the cold and it is running lean, you should rejet it for the colder weather, check you plug and check what it looks like.