busa piston swap - work in progress

Why not just get some wiseco race ones? just outta interest

I know they are pricey but if you are doing a performance mod...

Prob coz they are £200+ a set, you can go mad and get an 850cc set and bore it out. Dont think the crank would hold out for long though.

I also think the Wiseco ones are heavier.

Originally Posted by barwel1992

yup that, my bike already revs more than it should i have seen 12.5k on the rev gage direct from coil

I thought the rev limit was electronic at 11.5k so anything you would do to the engine wouldn't change it.

[yorkie_chris]

Originally Posted by Rai86

Why not just get some wiseco race ones? just outta interest

I know they are pricey but if you are doing a performance mod...

Wiseco weigh a ton and have been shown to fail. Not worth the price.

CP is where I'd look if I wanted big bore.

Originally Posted by hardhat_harry

I thought the rev limit was electronic at 11.5k so anything you would do to the engine wouldn't change it.

Some K3s slipped through with no rev limiter.

I would not make a habit of going over rev limit, busa pistons or not. For a start there is no more power up there.

Originally Posted by yorkie_chris

Wiseco weigh a ton and have been shown to fail. Not worth the price.

CP is where I'd look if I wanted big bore.

to rai's question ^ that

Originally Posted by yorkie_chris

Some K3s slipped through with no rev limiter.

I would not make a habit of going over rev limit, busa pistons or not. For a start there is no more power up there.

naa i dont, i just slipped a gear and 12.5k flashed up. would replacing the ecu sort the problem out ?

[yorkie_chris]

Rev limiter is part of the ECU function so yes. Not sure whether later ones would fit

Originally Posted by yorkie_chris

Rev limiter is part of the ECU function so yes. Not sure whether later ones would fit

the restricted ecu is the same from k3-6 so the stock ecu from a k4-6 might work

[yorkie_chris]

I would say it's pretty certain it will. AFAIK it is only K3s had the limiter issue, but maybe K4s too. But it did only affect some K3 so maybe you'd be fine just swapping for another of same year.

yeh, will have a look around

bike will be back on the road before i get round to doing the piston swaps as i kinda need it but first to sort out the snapped exhaust stud, if i cant get it out when my bloody tool comes. if i end up dropping the head cuz it wont come out im just going to do the piston swap there and then

Are you haveing any crank work done to compensate for the lighter Busa pistons? Or is this not required?

I was under the impression that crank was balanced to Pistons and visa versa.

I remember changing some two stroke pistons and leaving the crank the same and you couldn't (literally) hold the bars over 5000 rpm. Even after crank work is was way buzzier than before the swap.

C