is a OEM KXT piston cast or forged?

[joe_f7]

just wondering because all i can find for a replacement for my 86 KXT is a forged wiseco, and i know they can be picky in the snowmobiles i've put them in.

[tecat-z]

Oem's use cast pistons in 2 stroke apps. Tighter fitment is allowed, and a bit more resistant to siezing.

[InPiEcEs]

Oem's use cast pistons in 2 stroke apps. Tighter fitment is allowed, and a bit more resistant to siezing.

Yes sir........most OEM stuff is cast.......Cheaper to produce. I think either one would be just fine for most. With the 4-strokes, at least car and truck, maybe ATV, as well, you also have hyperuetectic pistons, as well. Correct me if I'm wrong, but I believe cast expand less than forged, but are said to be somewhat less tolerant of abuse, ie heat, higher horsepower, etc. Forged is fine, as long as the cylinder is bored for the particular piston being used, and seems to hold up better for higher performance apps, and most good machinists know what's up when they do your cylinder, as well.
I would rather pay a trusted guy a bit more to bore my cylinder, knowing it will cost less in the long run.

[cr480r]

Wisecos work just fine as long as there is adequate clearance... and you give the bike a lil warm up time... Every 2-stroke I have owned has had a wiseco in it... cast will last longer, forged will take more abuse

[Ed200x]

All stock pistons are cast. The other guys are correct in that more clearance is needed for a forged piston due to it's higher expansion coefficient. (It grows more as it gets hot) The forged are the way 2 go as they are stronger and lighter than a cast piston, you just need to warm the motor up to operating temp before riding as they do rattle a bit until they grow. Nothing to worry about. (I had a built SB Chevy with forged pistons that sounded like it was comin' apart for the first minute or two after a morning startup, but never had any problems & I believe they lasted longer than the stockers.)

[joe_f7]

so if i buy the wiseco oem replacement piston for my 250 will i have to get the cylinder redone for the clearance or did wiseco already take that into consideration when they produce it?

[cr480r]

so if i buy the wiseco oem replacement piston for my 250 will i have to get the cylinder redone for the clearance or did wiseco already take that into consideration when they produce it?

They should already have adequate clearance... the pistons are undersize of the actual bore size...

[joe_f7]

i'll just have to see if my motor is stock bore when i rip into it and set the ring end gaps and be done. i would like to find a oem though.

[InPiEcEs]

You're gonna wanna measure it up, just to make sure you have the proper clearance before you just slap a piston in. As long as the clearances are good, you'll be fine.
If you have too much, you're gonna need a bore, unless you have Nikasil.