going over 66mm on stock jugs?

[trail rider]

got a cheap banshee that im rebuilding/fixing up to sell, and the cylinders have alot of wear with 65.25's in em, compression before tear down was like 50/80 psi (and surprisingly it did run but had to be pull started) the insides are not scratched up and I ordered some 65.50mm wisecos, but the shop that does my bore jobs called me and said that the cylinders are not even gonna clean up decent with the 65.50's. so my question is, should I try 66mm, and hope it will be enough to clean up the cylinders, or would it be safe to just go to 66.25mm (1mm bigger than what was in it)? or would I be asking for trouble with heating issues?

Edited January 3, 2010 by trail rider

[TJScott]

my banshee is bored to 66mm and takes more abuse than any Banshee should ever have to take and 0 problems. the best thing to do is have them go with 66mm and see if the cylinders are good after that. if they arent i would look into re-sleeving or new cylinders.

[bebetekbanshee358]

wel it depends what u want to ride. if ur gonna be duning and trasils i wouldnt recomend it.. the cylinderwalls are way to thin and u will heat up alot... if u want to drag race ill give it a shot.. ur only going for a 5-10 seconds blast and ur cooling down after that....u will make crazy power.. but not reliably for a trail motor......just ditch or sell the jugs and go big bore. imlooking into doing it my self.. 68mm with a+4 stroke.. im 250+lbs i need the power to get me going

[alf44]

you will be fine with a 66mm bore. just keep it maintained and run your mix the same. Im doing a 66mm bore and using blaster pistons and a 4 mill crank. 396 dude. hell ya.

[sleeper06]

I had a 4mil trail bike that was 66mm ported and beatin for three years with no problems,maintaining only things that broke while riding,keep in mind if you do go bigger than .080 over(66mm) the domes need to be cut if your running a cool head

[trail rider]

I had a 4mil trail bike that was 66mm ported and beatin for three years with no problems,maintaining only things that broke while riding,keep in mind if you do go bigger than .080 over(66mm) the domes need to be cut if your running a cool head

 

well im plannin on sellin the bike after its back together and running, so im not to worried about how long its gonna last. all im worried about is getting a fresh bore with good compression. its pretty much gonna be a stock motor with fmf's. stock head too. and another thing is, I can get some 66.25mm pistons CHEAPER than some 66mm's.

 

and one more quick question, are the blaster pistons the same as banshee pistons, or do they have different pin heights?

[bigborebanshee]

Blaster pistons have a different pin height,they are best used on stroked or long rod engines

[Burt Reynolds]

well im plannin on sellin the bike after its back together and running, so im not to worried about how long its gonna last. all im worried about is getting a fresh bore with good compression. its pretty much gonna be a stock motor with fmf's. stock head too. and another thing is, I can get some 66.25mm pistons CHEAPER than some 66mm's.

 

 

Wow remind me not to buy it......

Edited January 4, 2010 by Burt Reynolds

[No Limit Powersports]

Blaster pistons have a different pin height,they are best used on stroked or long rod engines

 

Blaster pistons or 573's have a 5mm higher pin height for a 115 rod or long rod. Stroke does not matter. So yes the 573 can be used if its a long rod (115mm).