250 will be plenty power.start on begginer route,enjoy yourself.

clean the points,they often come with packing grease on them.use brake cleaner and nice clean cotton rag.

this is common,take carb of,and o ring that goes on flange.get a piece of glass and sand paper,and rub till flange is flat.redrill 2 bolt holes.now wash out carb well,you dont want any sand to go in engine.the glass is a very flat surface.hope this should fix your problem without replacing carb.

put whole carb in boiling water,it will nearly fall out.

these engine run hot at best of times,so powder coating head and barrel it will get even hotter,you will also need oil cooler,and best oil you can find changing oil every time you use it.

i bet its tight getting old nut of.if so push to local garage ask nicely if they would use a air gun on nut.

bottom end is the same as mtx 125 200.with the balancer gubbins left out.same clutch etc.not sure where to get piston?japan only? these and the tlm 240 engines same bottom ends.but the tlm 250 ,totaly different i had 240 for 5 years,only put a spark plug and changed oil in once a year.very reliable.ive got a 200,very nice to ride/