Hi to all

Have anyone tried wossner pistons in their NSR250's before?
My bike is road going and i'm just maybe interested in
changeging from OEM honda pistons to wossner.
Would it work?
will it be not to bad on the reliable side?
The only reason why i'm thinking of it is because it is
a little cheaper than bringing in OEM honda pistons
and as it is a lighter piston atleast its got 2-rings.

I am a little down on compression so maybe have to put in
new pistons to fit the barrel size. (only doing 110-115psi)
Barrels have been plated less than a 1000km ago.
Any info would be appreciated.

Hi Harold,

We used Wossner pistons on a friends bike which lasted one weekend at the track.After which he had to buy another set of pistons and a Nikasil so not so cheap... Be very careful with regards to piston to wall clearances, especially after a re-plate from NSC.

Two other things to mention :

1. The wossner piston is shorter so you will have to cut your barrels to accommodate or face loosing the compression.
2. The wossner ring pin runs over the intake port instead of over the bride between the two ports like the OEM piston so potential ring catching there. ( This is basically what happened because of the PTWC being too small. )

Cheers
Mario

P.s I do have OEM pistons in stock so email me if you need.

Thanx on the info.

Do I have to take off my tops to measure my barrel to get the right piston size?
Where in the barrel is the best place to measure? just on top of the intake ports
or closer to the top?

Chat soon

Leave your heads on , just loosen the 4 nuts on the base and check from there .

That sounds odd. Are these Wossner pistons made for the nsr250, or are they RM125 pistons that 'fit', or something else? You'd think if they were made specifically for the NSR they'd be the right height and have the ring clip positions sorted...

If I could run Wossner pistons in my NSR300, I would. They look very nice and very light. Would trust them over the Weisco forged jobs. Then again, I have ART pistons or some such in it atm :S
_________________
MC21 Honda NSR250. TYGA 300 conversion.

No one make a piston specifically for the NSR's except Honda. They are all for other bikes, normally dirt bikes like the RM125 you mentioned...

If you want Wossner pistons for the nsr , get a few guys together and send them a sample and a request . They will make for you . There are other guys that have done this .

Do you feel the new wiseco pistons for the 300 are no good ?
Mine are due any day now and will report back .

Well, I don't know where I stand on Weisco. Had them before and they went well, though I sold both bikes before I ever had to see how long they lasted. Heard problems and people saying they're a bad fit etc and need a long time to warm up and expand (which isn't a problem for me as I don't ride my NSR before it gets to 60C, or if I do, it's down a hill and I keep it under 6,000) but the piston is said to slap a bit until it expands. Anyway, that's the general consensus from the KTM 2 stroke guys. Different for an NSR... maybe

Anyway, I like the Wossners as they're moly coated and look very strong and light. Heard good things.

I just recovered a thread (five minutes after my previous post) that was discussing Matt at TYGA getting in a new batch of Weiscos AND Wossners for the 300! I left a post asking where it's at as I couldn't find anything on the TYGA site.

I have been taught to warm all bikes up before you cane it . The reason i was told is that the wiseco pistons for eg will have a bigger clearance to accomodate the epansion when they warm up .
I see that different groups of bikers like certain pistons . In the end , i think a forged , moly coated piston is the same from either brand be it vertex , wiseco or wossner IMO .

I will weigh the new pistons when i get them . Hopefully the new ones are lighter than the cast ones for the 300 .

Vertex apparently make both forged and cast. The KTMs run cast, though. Pros and cons for both, but the KTM guys are biased towards the cast Vertex pistons. Not sure where I stand though I'll stick to OEM on them.

as an update for 300 pistons , my cast one with 2 rings on weighs 172grams and the wiseco i have with 2 rings on weighs 166 grams .
Not much difference .

Not at all, ten tenths of bugger all, really. I'll wait to see what happens with the Wossners.

If we want wossners , then we need to get some confirmed buyers and get the ball rolling .

Did you read all of the other post? Matt said he was getting some soon... should mean that they've agreed to make them already.