Hia, I'm in the same boat as you matey. I just got a 2008 montesa 4rt, did the crank case oil and the gear box oil, what a Twa* it was to for me being the first time ive ever worked on a 4rt. I had hassle with a number of things, firstly was the removal of the oil filter, i managed in the end and on putting new one back in the o ring was a Twa+ to put in place, Job done though.
The clutch side was alot easier to do thank goodness. The last and only part i am still struggling with is replacing the bash plate. When I took it off it sprang off once I loosened the bolts on the front. Trying to put it back in place will have to be done tomorrow morning with the assistance of a mate.
PS when you ever buy a bike off someone never take it for granted that it has been serviced recently. When I got the bike home I was discusted at the state of the oils and filter, it obviously hasnt been done recently. It was jet black and the oil filter was happed up to the nines with black gundge. Im ganna check the water level and air filter tomorrow, to see if there is any more supprizes in stall for me before she goes out on a welly dabbing sesh.
Ah the joyz of playing with spanners and socket sets.
Hope all goez well on her maiden voyage the morra