Yamaha can't deliver pistons and some people use IT250 pistons in their TY's...

Ist it plug & play or are there changes to made ?

Difference in engine power ?

Is that the right piston ?

http://www.ebay.co.uk/itm/1983-Yamaha-IT250-WISECO-040-OVER-69mm-PISTON-IT-250-515M06900-/330786664446?pt=Motorcycles_Parts_Accessories&hash=item4d046beffe

You could give these people a try. http://www.tytrials.co.uk/trailandtrialsuk/prod_2768676-812-Full-Piston-Kit-TY250-Twinshock.html

thats for twinshock, need mono Piston....

but if you buy online from them and the parts arent in stock you wont know till you call them 5 days later

thats right im bitter

http://www.tytrials.co.uk/trailandtrialsuk/prod_2768783-15-Big-Bore-Piston-Kit-TY250-Monoshock.html

I had a TY Mono 250 ( with my 2 TS ) that I refresh with new 2nd o/s rings, when looking for those ring I found out rods rings and piston where very rare. So in my '' quest '' for ring I found a 3rd os piston and ring set at 220.00$ US.One and a half time the price of a genuine Yamaha TS piston I bought it. The original piston have close port as the one on the web site have open ones, according to Mick And.. they work very well but wear faster. If you want a picture of the original piston, pm me.

Guy

http://www.tytrials....-Monoshock.html

I zoomed in the pic, It's a Woessner 8180-DA for Yamaha YZ / IT 250......

IT Yamaha piston fits,but does alter the power characteristics which may not be to your liking

IT Yamaha piston fits,but does alter the power characteristics which may not be to your liking

TYtrials says :

Takes the capacity to about 263cc, 2mm over standard and offers a lot more bottom end grunt.

I will try the piston and test it, will tell you how it works....

Have a look at the wrist pin eight before buiyng.

Guy

Have a look at the wrist pin eight before buiyng.

Guy

Thanks, yes, I saw that only the early YZ / IT have 33mm Comp,height ( middle wrist pin to piston top end ), the later ones have 36mm, that won't fit....

Edited December 8, 201312 yr by hendrik

Give Nigel a call at Birkett Motosport, he has vast knowledge of mono Yams and the work-arounds

^{The Woessner Piston is to low, you Need to kut down the cylinder about nearly 2mm, I send it back ( got it on Amazon... ;-) )}

^{Here are more Details :}

^{http://www.trials.co...25ec6&start=100}

^{I will buy a Piston from Nigel, that will work ;-)}

Got new informations, Woessner 8175 will be the one, Yamaha TRI-Z 250, Wiseco 515M06900

Edited December 12, 201312 yr by hendrik