Hello,
My engine is knocking or should I say clacking, it seems to echo at the top end and sounds loudest near the exhaust manifold,. My local suzuki mechanic guesses  the machine  has been on its side and the crank bearing starved of oil. Has any one any suggestions as it is getting a little worse, and I need the bike for my new job as P/T fire man.

Pete... England.

Sounds like it needs a valve adjustment
Cool.
Srinath.

Welcome Pete,

It seems a little vague as to what is actually happening without actually being present to hear it in person. Clacking sounds are usually the valves needing adjustment. Have the valves checked to see if this eliminates the problem, as it is the least expensive. And check your oil level. Often.

If the mechanic does the valve adjustment and it still makes the sound then he is probably right, and it will need an engine teardown and rebuild.

Hope for the best, prepare for the worst.

I hope the best for ya.