Scooterotica

Just about to start a rebuild on an old Taffspeed TS1200 with Yam IT 175 piston and RD400 rod, I have looked at pistons, and there seems to be at least two variations of the piston, which one was commonly used in that conversion,

I was told and have just built one using 1980-1981 3R6

I managed to get a genuine Yam one as above - but you see adverts for Yam pistons covering 1979-1981 ??

then when you look at the pattern ones they are broader dates - wosner do an 1976-1981 piston and wiseco 1977-1981

I ve checked a couple of patterns ones and cant see any differences to be honest - based on the wosner/wiseco anything from 76-81 should be fine

Mine is a steel lined 225 TS1 barrel to 66mm using the IT175 piston and a RD 400 rod (115mm) in SIL webs crank - had to take 1.5mm off bottom of barrel to get squish correct - 116mm rod would have been better

Gaz

wasnt ther a post and pre mono shock version of that piston?

I`m assuming that any barrel mods would have been done when the engine was built about 16yrs ago ! its been one of the nicest lammy engines I have ridden, I took it out about 5yrs ago,while still running well but had done a lot of miles, replaced it with a long rod 230 motor, intending to re build it, only just getting round to it.not stripped it yet, it will be interesting to see what sort of condition its in, might only need rings,
seals & bearings

I have heard of ring peg problems - wearing with ring wear - so check them carefully

hopefully all well and a set of new rings on the top end is all needed

Have you had a look at the Yamaha Blaster piston, as used in the RB20?

I think the ring peg problems were associated with the standard original TS1 200 piston, looking to buy a new old stock piston, I just wanted to make sure it was the right one. Might strip it 1st before I buy the piston, not in any rush at the moment.

C. TS1 200cc, Yamaha IT 175
PROS. Excellent piston and rings either genuine or Wiseco, excellent con rod conversion, doesn’t require boost port moving, possibly the smoothest running TS1 cylinder kit.
CONS. Expense, requires a Yamaha con rod swap.
UPDATE June 2001; we have found that both genuine and Wiseco pistons to fail regularly. Both rings can spin over or pasted their ring pegs! Causing terminal damage! We are in the process of repairing cylinders with the Prox type pistons, to date we think we have cured the problem.

I thought I had read it some where......... old MB site

ive got an rb20 barrrel and piston piston in the garage - I`ll compare it to an IT one have

Gaz

gaz_powell wrote: Both rings can spin over or pasted their ring pegs! [/i]

I thought I had read bollox like that some where......... old MB site

ive got an rb20 barrrel and piston piston in the garage - I`ll compare it to an IT one have

Gaz

Dont think you will be dissapointed: Available from several manufacturers in excellent quality!