Looking for kz 250 advice/information

I just bought a 1979 kz 250 from an old friend.
Model KZ 250 D-002434. I saw the bike years ago and it looked great but have not seen it recently. I trust the friend so I bought it on the phone. About 5000 miles on it. Yes, only 5000......
She says it runs well but has a leak around the head gasket and the top speed is about 55 MPH.
She does not know if the leak is a weeping leak or something serious.
I'm just looking for information about this particular model.
Any known common problems?
Were head gaskets a common failure?
Parts easily available? Does 55 for a top speed on level ground with a 150 pound rider seem slow?

Anything else I should know? I'm an experienced engine mechanic but have not worked much on cycles.

Thanks for any help! Al.

Post edited by: alteran, at: 2006/05/25 16:39

Well, 5K on it and already leaking from the head gasket might be just about ghanging the gasket, tightening to spec and retightening after 300 miles, or could be something worse.

That 55 mph top speed is very slow for a machine that must hit 80 easily...

Maybe you can do a compression check just to be sure if rings or valve seating are OK, poor performance is often associated with poor compression.

Like kawadruida says, 55mph top speed is slow. That should be comfy crusing speed. If it is just a head gasket then changing it should not be to difficult since you are dealing with a single cylinder bike.

There are several posts here regarding the kz250. Use the search box and type kz250. Also check the archives and search again you should find some usefull information.