What piston?



  • Ahh! The rebuild is rebuilt. Also slapping like a diesel. I’m gonna need a new piston and am guessing people are gonna say Wossner, but what are Namura like?
    I’m running a 3MB00 barrel and head on a 3BN01 block. Do I need a 3MB00 specific piston or are they all the same?
    I don’t mind spending the extra money if it is genuinely worth it. I don’t want to pay for bragging rights IYKWIM. I don’t want a domed piston that increased compression to the point that it compromises usability. Unusable HP is unusable if you can only unwind it on a track...



  • PJME stated on their website that they suspect the Wossner pistons are being manufactured in China these days.

    Also, I noticed I needed to vastly up the jet on the Wossner piston.



  • Any recommendations? I am totally in the dark



  • @SpookDog FWIW I wouldn't put forged pistons in a 2 stroke unless there was no other choice. I wouldn't touch Wossner with a barge pole, either. In other bikes (not yet DT) I've had no problems with Mitaka, but if you want the best then Vertex are superb.



  • Any reason why you wouldn't use Wossner? I got a Wossner Rod and Piston in my Yamaha and other than needing to up the jetting I've not had any issues.

    I can't remember what I'm running in the RS. I've not had any issues with Wossner or Mitaka.



  • Cheers guys, feedback is good...
    I think Mitaka are made in Taiwan as well as Japan? With the later being the choice...
    Anyone had dealings with or heard about Namura? They claim a hard anodised crown and a molybdenum/Teflon coated skirt...
    They seem cheap for the specs which always raises a red flag for me. Don’t about the country of origin?...



  • @Calum In fairness I've probably been too harsh. I've no experience of them in a 2 stroke, but I wouldn't use a forged piston as I said - the principle benefits of a forged piston are irrelevant in a 2T, and there are some downsides too, involving the metallurgy of the alloy amongst other things.
    I've used Wossner car pistons many times at a former employer, (and bike 4T pistons once) and never been impressed with either consistency of size or finish, and quality of material. So I assume there is rollover in the way they produce bike & car product, making me sceptical. I ought to point out that I have been in motor race engineering for 35+ years and our standards are relatively high - maybe the Wossner product is fine, but when there's a better alternative...I take it.
    As for their rods - there is a very good possibility they are much more than adequate, probably even great. I don't know, but these days you've got to be using some hick chinese producer to get a bad bike rod...and Wossner have a reputation so I'd bet they are ok for the forces generated by a DT.



  • @SpookDog Taiwanese manufacturing often as good as found in Japan - in my experience. There is little evidence to support hard anodising of piston crowns when the piston is manufactured well in the 1st place. PVD coatings can be great, but unless designed in, and included in your bore finish & clearance allowances, a waste of time/money. It's very, very often just a sales gimmick as properly useful PVD coating is not cheap...



  • Don't knock Taiwanese. They're a skilled labour force. I've got many Taiwanese products and the quality of them is second to none!



  • Wow! Hold yo horses! I’m only going on what I’ve heard. Like I said, I’m in the dark here. I know nothing about Taiwanese manufacturing. I only know Japanese and German are usually best...
    Hence, I’m very interested in all opinions...
    Please keep them coming. I need other people’s opinions to help me through this mine field...



  • Basically, what replacement piston are you running, that you don’t regret?...



  • @SpookDog
    I've only used Mitaka in a few 250 engines & they have been fine, a good compromise between cost & quality. However I use Vertex whenever possible and they are the best I've found, whether for MX or circuit use.



  • I use mitaka they’re good pistons and a lot of them are surplus oem jap pistons according to them atleast



  • So Vertex or Mitaka seem the pistons of choice? (it was the PJME website that I saw the ‘cheaper made’ Taiwan Mitaka piston comment, by the by) I’m guessing I’m gonna go for the Vertex, if I can get it at the right price. Just for the guaranteed quality of nothing else.
    I don’t see any point in a forged piston if I don’t have any other tuning, or the knowledge to make use of its potential. It’d just be ‘lipstick on a pig’ 😜
    Cheers for yous opinions buds!...



  • Someone suggested to me a Makita Racing piston a long time ago.



  • athena r quality parts u wont go wrong with these



  • Yamaha TZR125 DTR TDR 125 Wiseco Piston Stock 56mm Bore 679M05600
    on ebay aint bad at all either they range .5mm and have 8 stages u have to have a rehone though to be sure u aint blowing your funds


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