on my mates bike '98 techno ,the water in the expansion tank isn't getting hot at all, but the radiator is hot to the touch ,should it not be like a car if you unscrew it , it pushes hot water out, any ideas, also the bike seems to run on a little bit when you rev up and release cheers guys

Sounds like it isn't circulating, check the water pump gear, isnt spinning on the shaft, the running on can be caused by it running too hot, same problem causeing both symptoms.

that sounds bad ishy, is it a big job? regards mick