DT125R ARCHIVE

NEV · Guru

Best piston to get?

Energized · DTR Legend

Hey guys i'm after an oversized piston what are your reccomendations or is geniune yammy good enough? + prices would be good ty

NorDt · Guru

The yammy might be the best i dont know. But i had a Wiseco. And it was really good. Had a prox too. Didnt notice any change. But the prox was in aluminium i think. so i swapped it for a wiseco.

Once with the wiseco i had done 20 000 km with it, Proper driving in is 50 000 km. And i gave my dt some proper throttle and got it up to about 75-80 mph. And then the rear wheel just stopped. the piston got stuck inside the barrel. I pulled the cluch, if i didnt i would have ended up in the asfalt. And when i released the clutch again everything was fine. apart from some rattling from the piston rings. Drove home the last 4 000 km home. Was a bit carefull. When i got home i put the prox back on and ordered some new rings for the wiseco. The wiseco piston didnt have a scratch. But the gap on the rings was waaay too much. i dont remember how much it was. but it was too much.

NorDt · Guru

I was very pleased with the wiseco.

NEV · Guru

When I was first looking at getting a piston for mine, I enquired about the Wiseco ones, and that chap Dave at roadanddirtbikes told me the advantages and disadvantages of Wiseco, I forget now exactly what they were but he reccomended the TZR one, same with Boyeson reed petals, he reccomended HY-Teck ones, bit cheaper and do just the same job.

Energized · DTR Legend

Ahh right, cheers lads think i might try your piston Nev. Is 58mm an okay size?? Seems like the pv would hit the piston on that sorta size?

the only way is YAMAHA DTR · Guru

get a forged wossner, you can almost smell the quality lol, its such good quality

http://bikepics.com/pictures/2087417/

NEV · Guru

Energized wrote:
Ahh right, cheers lads think i might try your piston Nev. Is 58mm an okay size?? Seems like the pv would hit the piston on that sorta size?

Aye deffo needs the powervalve ground down to suit, and the head gasket reamed out to suit too mate,

@The only way, he told me all about the Wossner forged piston too, someting about the way the barrel expands with heat and the way the forged piston expands, I may have it wrong, you'd need to ring him to check, he's the type of bloke thats more than happy to give advice, but IIRC I think the Wossner piston is better paired with a cast steel barrel, not an aluminium one.

the only way is YAMAHA DTR · Guru

my barrel is steel (non plated), forged pistons take longer to warm up and expand so need to be warmed up for a while for it to run nicely

Energized · DTR Legend

Hmm i'm thinking about the wossner now, how much was yours bud? If not i'll see how much a genuine yammy 1 is :)

the only way is YAMAHA DTR · Guru

£85

DTCrazedKid · DTR Senior Member

i always buy wiseco pistons, never had any problems with them and they seem to last a pretty damn long while, even when battering the crap outta the bike