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1994 TY250Z Advise / help required

Posted: Mon Aug 07, 2017 5:03 pm
by colin jay
Hi All, I have recently purchased as fairly original but somewhat neglected 1994 TY250Z.

I am currently giving it a quick once over to get it to a state where I can ride it and it will be safe and reliable. The engine runs, and it appears to be reasonably sound. So far I have found just a couple of problems, mainly with the chassis / running gear.

1. At some point the rear wheel was fitted with the disc pads incorrectly located, and as such one of the caliper pistons has been worn away where it has pressed/rubbed against the disc. The Yamaha parts list that I have been able to find online, only shows the rear caliper as a complete unit, i.e. the pistons are not listed as a separate part. The caliper is a Brembo, so I will assume that it was bought in by Yamaha and was probably fitted to other trials bikes made in the mid to late 1990's.

Does anyone know what other bikes used the same Brembo caliper, and where I might be able to buy a new caliper piston and piston seal?

2. While fitting a new rear tyre, I found that the rear rim has suffered from the typical 1990's Yamaha rim cancer, and there is a lot of corrosion inside the rim. The corrosion is bad enough to make it so that the tyre will not seal correctly as a tubeless tyre. I have cleaned it up and the rim is probably going to be safe enough to use with a tube fitted for the low level riding that I do, however it would be nice to fit a new rim and run the tyre tubeless.

Are there any modern tubeless rims that can be laced up to the Yamaha hub without having to modify things to much?

3. The bike is still fitted with the original tiny footpegs, the R footpeg hanger is a bit bent and should be easily straightened, however the footpeg itself is fairly bend and knackered.

Are there any aftermarket footpegs available that will fit this model bike? If not, does anyone know of footpegs that are available that might be easily modified to fit?

Thanks all, I will probably have more questions as work on the bike progresses.

A quick non-technical question to end with.

How common is this model in Australia?

Re: 1994 TY250Z Advise / help required

Posted: Tue Aug 08, 2017 8:00 pm
by The Hell Team
Hi Colin I will comment on the bits I know about.
I think your rim is 36 spoke, modern trial bikes use a 32 hole rim. if you want to run tubeless you will require a 36 hole Gas Gas tubeless rim from the late 90's laced to your rim. It's a common upgrade done on a lot of older bikes, and really the best performance upgrade you can do. The ability to run low pressures on a modern tubeless tyre like an X11 or X-Lite Michelin is a massive advantage.
Footpeg wise you can get weld on brackets that will accept modern wide footpegs. it also gives you the ability to relocate the mounting points somewhat, lowering and pushing back the mount point for better rear end grip.
We have both the rims and the weld on brackets at
if you can post a photo of the Brembo part we may be able to help with that as well!
Paul Arnott

Re: 1994 TY250Z Advise / help required

Posted: Wed Aug 09, 2017 12:45 pm
by colin jay
Thanks Paul.

You are correct, the rear rim is 36 spoke. I will check out your website re the rim and footpegs.

Attached are some pictures of the rear Brembo caliper.

The diameter of the pistons is 32mm.

The disc pads are SBS replacement pads that my local Yamaha dealer was able to get for me.

Re: 1994 TY250Z Advise / help required

Posted: Sun Aug 13, 2017 11:09 pm
by AndrewT
Pretty sure the rear brembo caliper on the TYZ is the same as the front one and is the same caliper as fitted on the front of the TYR Pinky- in which case you can get new piston and seal kit from - OR you could swap the front caliper onto the rear and then fit a 4pot braketec or AJP caliper on the front and get a much better front brake. Mounting centres are the same.

Richard Allen Allens Trials Spares in UK often wrecking TYZs and would probably have or be able to source a used rim and caliper either brembo or a used AJP or Braketec 4 pot one.

From what I can remember there were only 3 or 4 TYZs in SA in mid 90's - 1 with Sidecar (Todd K) Stefan Merriman rode one to 2nd Open place in 1994 Aussie Titles in the Barossa behind Graham Jarvis - I think Ben Z had that bike (Pink) and then there was a purple one (Scott R) - that might be the one you have after several owners in between.

Also complete rear brake assy on eBay at the moment ... 3aec2de767

Re: 1994 TY250Z Advise / help required

Posted: Mon Aug 14, 2017 9:16 am
by The Hell Team
I have the repair kits for those Brembo callipers in stock. They come with new 32mm pistons and the seals.
Our Part number is R260001

Re: 1994 TY250Z Advise / help required

Posted: Tue Aug 15, 2017 9:28 am
by colin jay
Thanks Andrew, I can remember Todd's sidecar, but can't recall having seen any TYZs ridden as solos, but then I spent the 1990s in the navy and only managed to ride a few trials in Vic on my bully outfit in 1992 or 1993 (hard to remember which year). I think Todd was still riding the TYZ when I came to SA in 2003 and started to get back into riding with the old Bully.

I am sure that when I get this one running and take it to a trial that someone will tell me all about it comp history.

Hell Team, thanks, I have just ordered a repair kit. I like to deal with locals before going off shore for parts.