[RH_Racing]

Hey guys, My buddy just built a 10mil cub. This after 3-5 gallons of fuel. A real hard break in. He tore it down and is worried he is LEAN. I Know by looking at this piston that he is RICH.

Heres the pic, lets get some input

 

[badassbanshee479]

looks rich to me. why did he pull the top end to check jetting?? does he know how to do a plug chop??

 

[dajogejr]

Gas or alky?

 

[RH_Racing]

QUOTE (dajogejr @ Aug 15 2008, 07:07 AM) index.php?act=findpost&pid=8261Gas or alky?
Gas and he didn't pull the top end to check jetting. He is changing domes.

 

[badassbanshee479]

ah... makes more sense now.

 

[camatv]

its got a lot of transfer velocity. and big wide sqish band ?? just guessing

 

[RH_Racing]

QUOTE (camatv @ Aug 15 2008, 12:35 PM) index.php?act=findpost&pid=8304its got a lot of transfer velocity. and big wide sqish band ?? just guessing


standard cub transfers and a really thin squish

 

[J-Madd]

Piston wash is a new concept to me that I just read about.

Any motor that has been ran rich that I have seen (according to plug chop and general running characteristics) has had a ton of carbon build up on it. With the piston wash theory, that would make it lean.

I still need more convincing on piston wash.

 

[RH_Racing]

QUOTE (J-Madd @ Aug 15 2008, 04:12 PM) index.php?act=findpost&pid=8315Piston wash is a new concept to me that I just read about.

Any motor that has been ran rich that I have seen (according to plug chop and general running characteristics) has had a ton of carbon build up on it. With the piston wash theory, that would make it lean.

I still need more convincing on piston wash.

Its back together now with less compression. The general conception is that the motor was lean. He went out on the jetting so we will see tomorrow.