A failed crank seal led me to tear my motor down and the pistons looked strange. I assembled this motor two years ago, fresh bore with new wisecos. Ran great the first year, had a few electrical gremlins last year but it was running nicely during the freeride until the seal opened up. The plugs never looked lean, the compression was good and the cylinder walls still show hone marks. BUT the top of the pistons look as clean as the day I put them in, the bottom of the pistons are BLACK. What would cause this?
Super Jet Weird carbon on pistons.
- Thread starter yamanube
- Start date
I figured that was why the pistons where clean on top (had pulled the blown head gasket and installed a billet head) but would that cause the carbon on the bottom of the piston?
#ZERO
Beach Bum
- Location
- Florida - U.S.A.
If the inside of your engine is black under the pistons it could be caused by short circuiting from the ignition timing being way off or the air leak.
I didn't really notice it anywhere other than the bottom of the pistons but I will have to look again. It just surprised me to see then entire underside of the piston blackened. It is not cooked on and wipes off pretty easily, just strange to see.
Freakrider
X247
- Location
- Tampa Bay area
Tyler Zane
Open Your Eyes
- Location
- Panama City Beach, FL
Interesting topic