Thanks for the suggestions so far... havent had any time to look at it
since first posting but i will try to follow some of the advice later
this week. Think i will start with the prop, as its the simplest thing,
then look at the adjustment of the gear lever (the cable which actuates
the lever is fine, and the hole it goes into on the lever is not
elongated at all), then look internally if that doesn't produce
results. Ive got a feeling that its either the dog clutch or the gears
not meshing fully... just by the way it suddenly jumps in and out, it
is quite a sudden, harsh action... although ill look at the propr first
i would imagine that this would be a much softer action if it was
slipping then re-gripping on the rubber boot.

Keep the advice coming and ill post any developments when they
happen...

Thanks Dave.