Old Tomy Set

When you open it up, all the bits will probably fall out but it's no big deal, there's no pesky little springs or anything like that. (Well, there is one spring, on the white plastic bit that's actuated by the reversing switch, but it should stay in place on the central arm of that piece.)

You'll easily figure out how to re-assemble with the help of Sunhuntin's tutorial. The only bit you need to watch out for is the reversing switch, which needs to be properly aligned with the relevant sliding gear/axle assembly, and it's easy to have it in the wrong place.

Thanks for the info Chris, I must admit after looking at the photo's on Sun's page I couldn't believe the complexity of the gearing in that engine, I mean does it really need all those gears lol!

Anyway when I get a quiet day and fancy a challenge I'll open her up and see what's what