AUTOBAHN \"FUN\"

[OB_jan]

oKE YOU MAKE A RUN FOR IT

 

[OB_THE MOTORHEAD]

go for it.me no like pistons with holes.

 

[OB_Kirk]

Okay, but correct me if I mess up. If you lean out an engine, they tend to "shoot ducks". This lean fuel mixture induced detonation causes higher than normal combustion temperatures, higher than normal combustion pressures, and most importantly, the combustion pressures "spike". This can melt, blow holes in, and crack pistons. It can collapse top ring lands down onto the top ring, binding the top ring and damaging the cylinder walls. The excessive heat can cause the piston to grow to a size that it was never intended to be, scuffing the cylinder walls and subsequently taking out the rings, sometimes to the point of seizing the engine. Basic bad stuff. Did I do it right?

 

[OB_Kirk]

Look for little flecks of aluminum on bone-white spark plug porcelins, or in extreme cases, cracked and missing spark plug porcelins or side electrodes melted off.

 

[OB_jan]

Okee,thanks ,have you checked youre ,s already after youre 205 mphrun ,and do you have stock pipes on youre bike?
jan

 

[OB_Kirk]

No, I haven't. Mine were isolated top speed runs starting at normal operating temps. I was at a little altitude so I don't think there was much chance of running lean. Also I am lazy. I did notice that one header primary has more brown to it than the others. I'm guessing that is the evidence of heat. I may need to use some Redline fuel injector cleaner stuff on it. 7,500 miles. Runs good. Fuel mileage computer holding steady at about 40mpg. Stock exhaust.

 

[OB_jan]

I heavend checked mine,but my header is grey after a speedrun ,14000 km on it

jan