Trials Australia Forums

and this is what I expect the cylinder studs will look like:

Hi Everyone,

Really nice work on the Peter Paice TY250 there David.
One of my latest finds!! I think it spent most of its life near the ocean and outside. Surprisingly, cleaned the carby and tank out of crud, found an exhaust for it and runs pretty sweet.



Chippy

chippy wrote:Hi Everyone,

Really nice work on the Peter Paice TY250 there David.
One of my latest finds!! I think it spent most of its life near the ocean and outside. Surprisingly, cleaned the carby and tank out of crud, found an exhaust for it and runs pretty sweet.

TY175.jpg

Chippy

Nice Chippy. Excellent patina and it's so rare to see a fuel tank that hasn't been caved in.
I'm thinking that exhaust looks very familiar

For the first time, I had two KT250 frames close together today and noticed that the upper steering head bearing seat is longer on one of them than the other.
I've had the same complete front end in both frames so there isn't a problem with interchangability.
Another interesting thing I discovered today is that the lower steering bearing is the same as a Mazda 323 wheel bearing .

I just collected some KT engine covers from the local vapour blaster. He does a great job.
I'm still deciding whether to do the black bits on the insignia or not.
Yet to get stainless screws for the sprocket cover.

Hi Everyone,

Nice work again on the David. I do like the Whine that a KT makes and I am interested too as to exactly what gears makes that noise. I also like the naming of the Peter Paice TY250 rattle can blue "Lahey Moto Blue".

Greg, "Rust is the new bling". I think that type of Patina is gravitating towards me now with the latest acquisitions....



A large amount of dust on them from sitting for who knows how long.

Chippy

Hey Chippy, I too love that whine from straight cut gears also on Fantics and Rotax motors.
I believe the quieter helical cut type transmissions spread load better but require thrust bearings to take the axial loads making these transmissions a little larger and heavier.
I like watching V8 supercar racing occasionally, you can certainly hear that straight cut gear whine when they give you cockpit audio, it's awesome.
With regards to Trials bikes, I think it was simply to reduce engine width and maybe reduce a little weight.

I got to do some more assembly on the KT250 motor today because the new cylinder studs arrived.
The background story is that I've replaced the conrod in a KT motor and the conrod that was the best fit is a few mm longer than standard. This means that a spacer plate is needed under the cylinder.
I've had the spacer plate for ages but only recently started to put the engine back together and decided to get longer cylinder studs, so that the cylinder holding-down nuts had full thread engagement.
The process of getting longer studs took longer than I expected because the first set of studs I ordered was shorter than original and I wanted studs 5mm longer.
The next set of studs turned up during the week and today I noticed that they were 10mm longer than I wanted (15mm longer than standard). It's easy to shorten them though so today became the day to fit the cylinder back on.
This shows the standard stud length.

This is the cylinder test-fitted with the longer studs.


And here is the cylinder fitted showing the spacer plate. I've ordered some nuts that are more colour co-ordinated to replace those copper-coloured nuts.

These photos are really just because I thought the new piston and the rebored cylinder looked photogenic

Its interesting that the pretty new piston has an arrow to show you which way it will make the bike go.