Genuine Ty250 T/s Pistons Anyone?

[alan_nc]

On my last 250 rebuild I used a DT piston (yes I had to grind the corners of the skirts). It's very minor and I did it with a Dremel. Engine has run fine for the past year, no starting or power problems ... I guess it might be a bit noisey, sort of guessing there.

I split the crank and replaced both big end and small end bearings when I did the rebuild. The piston top to pin and pin to window specs were right on.

I can't really see why the DT piston should cause any problems.

Alan

[feetupfun]

Yes, Wiseco are a quality piston, unfortunately the pattern pistons sold here are chung-ching rubbish or such-like, no-one sells Wiseco here.

Are the Wiseco DT pistons an exact copy of the TY item then? No machining, trimming etc required? What about the slots on the inlet side, are they the same?

The pattern pistons I was given were too long and the skirts had to be cut off to stop them hitting the crank (fitting them in a TY twinshock, not the mono) I was told they were probably DT items but I don't know for sure.

The Wiseco DT250 pistons are slightly different-loooking to Yamaha TY pistons, but the skirt is the right length, the pin to crown distance is right, the window holes in the rear skirt are the right shape and in the right place. The rings are standard Wiseco (two thin rings that are flat top and bottom) and piston kits are reasonably priced. Bought through SERCO (Brisbane, Australia)

While the Wiseco DT250 pistons work well in the TY250 twinshock, for the TY175 I prefer using PRO-X, which are made using the same alloy and manufacturing process (and look the same as) original Yamaha TY175 pistons and are also reasonably priced.

[marky g]

but from start up it rattles like it needs a rebore, have taken cylinder back off to check fit and all is well so must be the piston, any suggestions fro proven supplier of a real good + two piston for my bike would be much appreciated just to stop it sounding like a bag of spanners.

I was always told to buy Genuine stuff if I could get it, I've been dealing with a third party and I thought I was buying genuine bits, the last thing I want is to start the thing up and it sounds naff, the bore and piston kit has cost me

Edited April 5, 2010 by Marky G

[andy m]

As Woody says a lot of stuff now offered is chinky rubbish, you can't avoid it sometimes and they will even make the boxes look like the real thing. Back in the day the pattern stuff was good (RD250/350LC) The pattern stuff was also made in Japan poss at same factory with the box being the difference. ART PRO X and Wiseco all good but thin on the ground now. As said before try Birketts he knows,( he may not be answering the phone he's unfortunately had the thieves visiting, see the front page) but I did notice there are a lot on ebay USA but not sure if it's the same cr4p.

http://www.trialscentral.com/cms/showartic...?articleID=5392

Edited April 5, 2010 by bo drinker

[marky g]

Cheers Bo, funny thing I've just found the packet my Wiesco con rod kit came in and guess what....even thats made in china now

[Tillerman6]

On 4/4/2010 at 10:48 PM, feetupfun said:

I've used Wiseco DT250 piston kits in the last two TY250 twinshocks I've had rebored (5 years ago and 1 years ago) and they have both been been fine since - they haven't rattled and everything fitted perfectly

Feetup fun ,

  It was good to see that your post from way back in 2010 mentioned the DT 250 pistons from Wiseco.  They are still available according to their website today 8/14/2018!  Do you remember if you were able to just install them AS IS? or did they need any modifications?   Thanks in advance!

 

[feetupfun]

15 hours ago, Tillerman6 said:

Feetup fun ,

  It was good to see that your post from way back in 2010 mentioned the DT 250 pistons from Wiseco.  They are still available according to their website today 8/14/2018!  Do you remember if you were able to just install them AS IS? or did they need any modifications?   Thanks in advance!

 

In 2010 I said they fitted perfectly. That means I didn't have to alter the piston or the cylinder or the crankcase or adjust the ring end gaps to be able to use it. One engine was a TY250B and the other was a TY250D. I haven't fitted any Wisecos in TY250 motors since then.

I'm eventually going to re-bore my TY250A which is still on the original piston and rings, because I just rode a friends TY250A which had a fresh rebore and mine is a bit down on power compared to his, which usually means worn rings, especially if they are 44 years old like mine are. I'm thinking of using a Wossner piston kit this time. I'm not interested in just fitting new rings.

[Tillerman6]

On 8/15/2018 at 1:39 AM, feetupfun said:

In 2010 I said they fitted perfectly. That means I didn't have to alter the piston or the cylinder or the crankcase or adjust the ring end gaps to be able to use it. One engine was a TY250B and the other was a TY250D. I haven't fitted any Wisecos in TY250 motors since then.

I'm eventually going to re-bore my TY250A which is still on the original piston and rings, because I just rode a friends TY250A which had a fresh rebore and mine is a bit down on power compared to his, which usually means worn rings, especially if they are 44 years old like mine are. I'm thinking of using a Wossner piston kit this time. I'm not interested in just fitting new rings.

I wish I had gotten a chance to ride a recently overhauled TY to get an idea of what sort of power they should have.  I think mine was way down on the beans available, but I didn't have anything to compare it to.  It ran OK for put putting  around the yard, but this year it refused to start.  See new topics Clean out the tail pipe and what oil ratio to use.