300exc - which piston?

[Rmxer]

Hey all

Done a search but wanna know more!

Doing the top end on my 07 300exc

What brand piston to use???? Wossner??

thanks!

[vazza]

Get a stock one from KTM, can't go wrong. They're cheap as well.

[Rmxer]

$100 more from KTM, but you do get the whole kit gaskets etc, not that i need them

another question now, do i go for the I or II piston??

This will be the 2nd rebuild from new (so 3rd top end) and bike has 190 hours.

I have read that the II is the way to go unless you have a new cylinder in which case they use the I.

thoughts?

cheers

[t595]

get a wossner from mxparts and the base gasket which is about 8bucks from memory

[flyingcr250]

Get a stock one from KTM, can't go wrong. They're cheap as well.

i always just ran the KTM pistons in my '08 300 exc , the kits i got usually came with piston, rings, pin, powervalve seals, lots of different base gaskets, rubber head gaskets, povervalve cover gaskets, o-rings for the pipe, and a few other seals and copper washers, pretty good value i thought.

[Rmxer]

yeah KTM sounds like the way to go.

did you get the I or the II piston?

[honda_power]

iv used quite a few wossners, very good piston, never had a problem, and very quiet when compared to other forged pistons such as wiseco

[vazza]

i always just ran the KTM pistons in my '08 300 exc , the kits i got usually came with piston, rings, pin, powervalve seals, lots of different base gaskets, rubber head gaskets, povervalve cover gaskets, o-rings for the pipe, and a few other seals and copper washers, pretty good value i thought.

For sure, that's why I keep it standard. Can't go wrong, and the prices arn't even bad anyway. I did get a bit of a deal on mine however.

[Rmxer]

For sure, that's why I keep it standard. Can't go wrong, and the prices arn't even bad anyway. I did get a bit of a deal on mine however.

so do any of you know if you used the I or the oversized II piston??

[vazza]

I forget, it's been ages since I've changed a piston. What do you have in there at the moment?

Check with a KTM dealer??

[Kickaha]

so do any of you know if you used the I or the oversized II piston??

I would have thought you'd need to measure the barrel and decide on the piston from there

[Rmxer]

Turns out it has a wiseco piston at the mo

Reading over other forums seems like the number II one is used for pretty much every rebuild unless it is a new cylinder.

Think its gonna be the way to go

[little.whittle]

Your barrel should have a I or II stamped on it You need to match it with the correct piston to get the best fit

[honda_power]

if the 300 is anything like my yz250, a wiseco will be sweet in either

genuine yamaha come in a, b or c, wisecos has one piston for all

could be the way to go if your not sure what it is

[peadub]

Genuine II kit has a RRP of $314 and has everything you need
Give Sam the Parts Manager a ring if you want one couriered out We take credit cards

SAM-Pukekohe