[bksrt]

I tried for a few hours this morning looking at pics on google etc but I cant find a definite answer to my issue. I pulled the piston and sleeve from my Cen Genesis. It has a cut out at the bottom of the piston skirt. Does the cut out go to the exhaust side or the intake side of the sleeve?
TIA

[bksrt]

Over 20 views and nobody has had a motor apart and knows the answer?

[machzx]

look for an arrow on the crown it will point at exhaust
next check to see if the cutout matches the intake port
the burn on the piston will indicate the exhaust side too
it will have more carbon as the incoming fuel charge washes the carbon off the intake
im assuming this is a gasser not nitro
my guess is cutout goes to intake side
goodluck
good lesson for next time make a mental note or if u drink take a pic

[bksrt]

I took a mental pic, but then I drank. Gotta stop doing that.

Anyway, I have the piston in the right way, what about the cut-out itself? If that has a chunk missing or anything, will that cause the motor to not run?

Oh, this is not a gas truck, its nitro, for the record. Its a Genesis 7.7

[machzx]

cut out or a piece missing is a big difference
a cutout will look uniform and machined a chunk missing will not be as nice
if its a broken chunk toss it time for new parts plus then check every thing else for wear
hard to tell from here lol
your local hobby shop will help
good luck
ps most car motors are beat on pretty hard so dont be surprised if its the worst case

[bksrt]

No its a cut out for sure. Im a steelworker i know the difference between machined and broke but i havent had a chance to take a good look at it since i put the motor back together. If there is a piece of the cutout missing/broke that i didnt notice, can this prevent the motor from running somehow?

[Skidoo55]

Doesn't the cutout go to the front to allow clearance for the crankshaft journal?

[JayzRC]

The cutout goes to the intake side (carb) to clear the crank when the piston is at BDC..

[bksrt]

A little late but thanls for the help, thankfully that truck and god-aweful POS motor are gone and im running a much more reliable Losi 8b now with an Ofna Force .28.