feetupfun

There are two forums on here where you can ask Cota 200 questions. One is "Twinshock" and other is "Montesa". There are also facebook pages for Montesa motorbikes.

Your statement "this is my first time riding a trial bike" tells me that the bike may be working normally, because 2 stroke trials bikes like your TY mono are very different in engine performance and gearing to 2 stroke non-trials bikes. How about you post up a link to a Youtube video of you riding your bike so people can tell you if there is anything wrong with the bike.

Do you have continuity for the earth side of the ignition system? This relies on a good electrical connection from motor casings to frame and from frame to HT coil.

Assemble the piston on the rod, mark up the piston where it hits then remove the piston and remove enough on those corners to give clearance of at least 1 mm. As for physically removing metal, hold the piston without deforming it and use a file or a grinder or a sanding belt or a sanding disc.

Maybe a previous owner modified it to suit a different axle. If the hole is 12mm, the original threaded hole may have been drilled out and bushed to suit a through axle.

I've got a model 49 250 Sherpa T motor and a Campera 175 motor available. Both require overhaul. Location Gladstone, Queensland Australia

other options include WD40 and dishwashing liquid solution

Tubed Trials tyres usually go on and off so easily using hand levers I don't usually bother with lube but if I was using a machine to fit one, I would use lube to make the sliding part move nicely. I do use lube when changing knobby tyres with hand levers because they have such a stiff construction.

I haven't heard of trials bike stainless steel rims previously. Where did you source them from?

What does the rest of the extra motor look like? The DT250 radial fin head motor looks quite different to TY250 motor in many ways. Shape of engine covers, location of kickstart shaft, length of motor. It's a popular thing to fit the DT250 radial fin head to TY250 twinshock motors.

the 19M means Cota 172. The rest is the production number

More info needed. How far is the fuel getting?

I saw a XISPA being ridden in a trial when they were first imported into Australia, by a person who I think was the importer. I'm thinking it was about 2010.

You can usually lean bikes on their side to work on the clutch without draining the oil

Model 159 is a 325 Sherpa T from the mid 1970s. Where located? Does it run? When was it last run? What is its riding/maintenance/rebuild history? Front tyre looks like a 1970s Pirelli. Shocks look like original style Betors. These things make it look like it might have sat unused somewhere for a long time