i hav a scorpa 1996 250, its a very clean bike with no faults as far as i no (ive only just got it) i used to ride motocross bikes and i had a to change my top end a lot, is this the case with trials bikes and if so how often, and how often should i change my gear oil and whats the best oil to run it on? and wats mix should i run it on? last question when the crosser used to get hot i had to let it cool right down then it was good to run again so the top end didunt go. do i have to keep an eye on the temp of the scorpa

any help would be great, thanxs matt

Matt, top ends in these things last forever, at least in MX terms. The combination of low rpms, double rings, and small port sizes mean they past MUCH, MUCH longer than your previous MXer. Guys go for years on a top end. How frequently you change them is up to you and how much you ride.

As for gearbox oil, there will be a dozen different answers to this one. Personally I like to run ATF and change it frequently. I'm overly anal on this stuff and change mine every 2 riders. ATF is cheap, works well with clutches and provides adequate gear protection, particularly when changed frequently. I'd rather have cheap, clean oil than dirty, expensive stuff myselt.

You also don't need nearly as much oil in the fuel mix as with MX. Again, much less stress and more low rpm running/idling. I normally run 80:1 in a liquid cooled trials engine. Anything 60:1 - 80:1 should be fine with a good quality oil.

Water temps are generally very well controlled on trials bikes. Most have a themostatically controlled fan that helps keep air moving across the radiator when moving slowly or idling. Overheating shouldn't be a problem.

Hope that helps.

Only use a fully synthetic oil at that ratio though, not a "synthetic blend" oil.