feetupfun

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

The only 326cc Alpina is the model 99. All the later "350" Alpinas were 348cc. Model 116 is the next "350" Alpina model after the model 99.

If you're worried and want to check it out, measure what temperature it is running at. A thermal camera is great for this. If the cooling fan duty cycle is more than about 50%, then I would be checking coolant level, restrictions to airflow through the radiator and if the fan is running the right direction.

Your photo of the inverted carburetor shows that you have omitted to fit a gasket/copper washer under the float valve seat/body. This omission is a possible cause for the float bowl overflowing

In late 2023, I investigated a hot running issue with a friend's low hours 2022 TRS 300. It ran poorly when trail-ridden once warmed up. I found some things wrong. 1 the coolant level was very low. From memory it took something like 300 ml to get the level up where the book says. 2. The fuel filter inside the fuel tank was restricted by debris. 3. There was way too much sooty carbon on the piston crown and inside the head for the hours it had run. 4. I found something that I don't know is wrong or not, but seemed odd to me. It had both a resistor spark plug and a resistor spark plug cap. 5. The reeds had wear marks from touching the open stops. I found out that the owner had been using Castrol 747 premix oil (the one with some castor oil in it). I de-coked it. I cleared the fuel flow restriction. I fitted a non-resistor spark plug. The owner then ran it on semi-synthetic premix oil. It ran fine. The reeds are going to be replaced soon. I suspect the running issue was being caused by the engine running hot due to lack of coolant, float bowl level going low due to fuel filter restricted and too-high compression ratio due to carbon build-up.