feetupfun

I'm glad you mentioned using the KT triple clamps as well as the forks. Did you realise that KT triple clamps are a lot further apart than TY triple clamps, so there will probably be some work involved with fitting the KT triple clamps into a TY frame. I haven't tried this to know what's required but at least the angular offsets of the KT fork tube holes will be incorrect if the KT triple clamps are moved closer together. The other stumbling block there is that the TY steering stem may not fit the stem holes in the KT triple clamps. As for attaching the TY brake link, it would be pretty easy to make a clamp that fits around the left side KT fork bottom for the TY brake link to attach to. No idea what spacers might be needed for TY wheel in KT forks with KT triple clamps. If you have a TY wheel or TY forks in their triple clamps and some KT forks in their triple clamps, you can measure them up and compare. Also have a think about where the KT fork tubes will end up at full lock relative to the TY fuel tank. Unless you limit the steering angle, I suspect they might hit the TY tank. This is because the KT triple clamps are designed for leading axle forks which usually positions the fork tubes more rearwards when straight ahead and closer to the midline of the bike at full lock, compared with (in-line axle forks) TY triple clamps. For what it's worth, the standard angular offset for both sets of triple clamps is the same (1.5 degrees). I modified my KT triple clamps to reduce the angular offset to achieve the same trail dimension as a TY (to make my KT steer better). You could do something similar to a set of TY triple clamps to achieve the same trail as a KT250 with a lot less trouble than doing a front end swap. However, I'm only guessing that this is what you are trying to achieve. What are you trying to achieve?

Yes 4 pot front brakes were a huge advance in brake control compared to 2 pot. The EVO also feels substantially lighter to ride than the Techno. I remember riding my first Rev 3 in about 2001 and being amazed at how light it felt to ride compared with a Techno.

I've done it the other way around, fitting TY250 forks to a KT (wanting to increase the trail). I used a TY wheel. An axle spacer was needed for this. It was just an experiment and I went back to using KT forks on my KT. There were two problems with the TY forks on the KT. The amount of trail was too much which upset the steering and the front mudguard hit the exhaust header on full compression of the forks. I then modified some KT triple clamps to provide only about 5mm extra trail over standard and was very happy with the result. If you fit KT forks to a TY250, the KT wheel assembly will be a bit too wide because with KT triple clamps, the fork tubes are slightly (2-3mm) further apart than with TY250 triple clamps. I've not tried to fit a TY wheel to KT forks. KT forks are longer overall and have more travel than TY250 forks and would reduce the trail by about 20-25 mm due to the leading axle design. They are functionally very similar inside with the main difference being that the KT forks do not have anti-topping springs. They are so similar inside that you can use TY internals in KT fork tubes and vice versa. It sounds like a fun, interesting project.

A standard 250 1997 Techno has a lovely soft motor. Technos came out in 1994 and were highly responsive - probably too responsive for the average rider. The 1996 model was made much easier to ride for the average rider and it stayed like this for the rest of the years of the Techno (96, 97, 98, 99). By the way, is your Techno a 250 or a 270?

One way to judge piston ring seal without pulling much apart is to inspect the cylinder wall via the exhaust port or the plug hole, looking for dark areas (carbon). Carbon on the walls indicates piston ring blowby. Be aware that trials two strokes nowadays commonly suffer from having the rings stuck in their grooves by gum and carbon. This can happen quite quickly depending on how the bike is ridden, the type of premix oil and how well the bike is jetted.

TRS sells electric start 250 and 300 two strokes and they are very popular.

The ball and spring can be installed or removed with the engine assembled

You can use the TY175 head or the DT175 head. If you use a DT175 head, the compression ratio will be higher but you may need to trim the head fins for exhaust pipe clearance. You can mount a clutch cable holder on the engine casing or on the bottom cylinder fin. The DT175 cylinder fins will not interfere with anything physically. Trim them if retaining the original TY appearance is important to you.

DT175 1974,75,76,77 (DT175 ABCD models) cylinder will fit and function well but has different finning outline to TY175. I have not tried or measured up a CT1,2,3 cylinder.

Which brake plate is standard/correct depends on which hub is on your model 92. Also, they might both function OK. Can you do photos of the hub showing the brake drum and an external view showing the finning and both spoke flanges?

Here's the OSSA cush drive puller photo

Yes, quite impossible. "Fingers" on a puller made to fit in there are not strong enough for the job by a large margin. The puller needs to pull on the whole surface. The Montesa primary drive crankshaft gear of the same era as the OSSA cush drive is also on a taper and is also impossible to get off with a universal puller so it is not just OSSA who did this back in the day. I'll post a photo up later when my cloud storage is talking to me

200 Euros labour plus parts sounds quite reasonable to me and even cheap if they have to source or make a special puller. Do they know what's involved?

Yes it's not easy but are you saying you can't find where to buy the special puller from?

Triad, if the primary drive crankshaft sprocket has a cush drive, then it is an easy job to change the crankshaft seal, but you need to buy a special puller for the cush drive. These pullers are available from vintage OSSA parts suppliers in the UK and USA. Buy a primary drive cover gasket and crank seal holder gasket while you are at it.