Scooterotica

Just putting my RB back together, useing a MB piston, and have noticed the windows in the piston extend beond the inlet into the barral, has anyone matched the inlet to the windows or would this be too much for the rings. ive left as is, but would like to know for next time iam in there .

just ring them up or you will be accused of being an internet warrior for suggesting things arnt quite right :ninja:

shocky wrote:just ring them up or you will be accused of being an internet warrior for suggesting things arnt quite right :ninja:

"Arm chair warrior" is the correct term

Are you sure that the rings reach down that far?

If you widen the port too much, you may cause the piston to rock at BDC, which will induce wear.

Knowledge wrote:Are you sure that the rings reach down that far?

If you widen the port too much, you may cause the piston to rock at BDC, which will induce wear.

Martin the rings come down as far as the bottom of the finger in the inlet, just wonderd if anyone had botherd to do any fettleing, and if there was anything to ba gained, ive used the MB over the asso because the cut outs are smaller around the gudgion pin, it looks a nice bit of kit .

eibargum wrote:Just putting my RB back together, useing a MB piston, and have noticed the windows in the piston extend beond the inlet into the barral, has anyone matched the inlet to the windows or would this be too much for the rings. ive left as is, but would like to know for next time iam in there .

Dont worry about it m8 leave as is.

Main thing people should be aware of is the ring peg positions on MB pistons are different
to the AF Asso's. Problems can occur if widening the RB22 boost port

You can not widen it as far on a MB piston as you can on a Asso.

But saying that Ive heard MB's are altering there ringpegs, dont know how true this is
may be Mouse or Ian can confirm.

Cheers smiffy, i,ll leave well alone then , only asked because its a new piston with big rectangular windows in, if you dont ask you,ll never know .

eibargum wrote:Just putting my RB back together, useing a MB piston, and have noticed the windows in the piston extend beond the inlet into the barral, has anyone matched the inlet to the windows or would this be too much for the rings. ive left as is, but would like to know for next time iam in there .

Gary, my inlet has been matched to the windows on an MB piston. Inlet floor was lowered and radiused as well.

Thanks Simon, does your MB piston have the larger rectangular holes or the round ones .

eibargum wrote:Thanks Simon, does your MB piston have the larger rectangular holes or the round ones .

Rectangular.