New pistons?

[MWC]

I am getting ready to have evil port my jugs and I am wondering if I should get new pistons while I am at it. I am not going to bore or anything just hone if I change pistons. What do you guys think? I have had people tell me that the stock pistons are the only way to go if I am not going bigger, any comments?

[91LT250R]

I see it's an 04 - has it ever been rebuilt? If not then I'd say definitely get it bored out and put new pistons in it while you have it apart. It will save money in the long run. And I think the consensus is that Wisecos are great pistons. Probably a lot cheaper than Yamaha pistons too.

[Yamaha_Freak]

a sleave will last 200 hours on it before u have to bore it out..about 3 sets of pistons then u bore it out..i would recommend new pistons but leave it same bore

[MWC]

no, never been rebuilt,but it is still fairly new

[MWC]

Originally Posted by banshee-freak

a sleave will last 200 hours on it before u have to bore it out..about 3 sets of pistons then u bore it out..i would recommend new pistons but leave it same bore

how do you know when your sleave is toast

[Yamaha_Freak]

use a micrometer..and find oem specs it should be within .0005 of recomendations before u need to bore it

[flotek]

wiseco prolites are the only way to roll ,but the clearance wil lbe slightly more onthem compared to the stockers ,wiseco are just plain bettter pistons period , when a builder gets it ,they should check the cylinders wit h a dial bore gauge and see if it ll be okay to run . after tthe port/polish it gets a hone job to break the glaze on the cylinders to allwo the rings to seat and stay lubricated . stock pistons are shitty IMO ,they are casted and are less precise and consistant i n every way, also they have more flaws and a rough crude casting o n the crown and small uneven intake windows.when carbon builds up o nthe crude roughass stock crown it builds up fast then it wil l loadup/pitt up your squishband and make your bike overheat aLOT and ru n like ass . wisecos are lighter they have a very smooth fine piston top that resists loading up with carbon and nice large intake windows .they are pretty sturdy for aggresive port jobs too .