Yamaha TRX850 Enthusiasts Forum

Will be a laugh to see what they will bring...

http://cgi.ebay.co.uk/Yamaha-TRX-TDM-85 ... 2c5c899b39

I wonder about ring availability, unless they utilise oversize stock TRX rings.

Mincehead wrote:I wonder about ring availability, unless they utilise oversize stock TRX rings.

Arias are pretty big in both japan & US so probably they can be sourced...!?

Are these definately Arias pistons kw?

Mincehead wrote:Are these definately Arias pistons kw?

Yes if they come from over racing they are, they used arias...and from memory the cc is correct...also the high comp...

Well if they`re definately Arias pistons the rings are readily available, here in the UK too.

So, anyone here buy those Over high comp pistons and bored block then?
Just short of 271 quid they made in the end, bit rich I thought.

I was watching but when the feeding frenzy started i hopped out of the water. When the time is right i think i'll go the 900 route like killer has.

The seller spoke of a big end failure in the motor they came from, they `may` have kissed the head and suffered microscopic fatigue fractures. Plus, they`re heavier than oversize TRX pistons so you would very likely need to balance the crank assembly too.
Arias are good pistons, but second hand and at that price? Not for me!

I bought them - and yes - worried about how they look...
Also bought V2 cams anf flowed head from same seller. Have TDMR with two KN`s, Laser Pro Stock, electric fuel pump so had to be next step i thought...
Anyone know where in UK I can get new piston rings for theese pistons?

Contact Arias UK in Billingshurst:

http://www.ariaspistons.com/distribution.html

So, are they scored, how do the crowns look?
The images on Ebay could have been better. You`re aware that they are much heavier than oversize Yamaha pistons and you should have your crank rebalanced?
Oh, forgot, hello and welcome.

Thnks.
Havent got them yet - will post and let you know. No I didnt know they are hevier.
Are TRX and TDM pistons and crank ballanse different? Going to use them in a TDM.
Great forum by the way.

Hi Rune.

Going to use them in a TDM

You heathen!
Over pistons should fit in a TRX - not a TDM

If you get tired of your project, I am interested in the set for my TRX

Hilsen Thomas.

Runehadding wrote:Thnks.
Havent got them yet - will post and let you know. No I didnt know they are hevier.
Are TRX and TDM pistons and crank ballanse different? Going to use them in a TDM.
Great forum by the way.

If you`re using them in a early TDM motor then yes, the crank is a 180 degree and not 270 as in the TRX.

It will fit in a late 4TX TDM - wouldn`t it? That one has the 270 crank as the TRX?
Anyhow I`m not using it in the engine I have, I`m after a donor engine to do this build, but I didn`t know it wouldn`t fit a 180 crank...
So thanks - and if I give up the project and sell the bits, I`ll post it here.