i reckon he's telling porkies
For a start why is part of the engine black, these bikes shipped with grey engines, tho something in the back of my mind thinks that the real early ones had black engines. There was never a combination of the two.
Secondly these bikes will go for ever, 100k miles without opening the engine is not unheard of. General rule of thumb is to not open a engine up unless you absolutly have too
Found the bike on ebay
here
34000 miles on a 01 plate, it's hardly moved, mines an 06 and has 24k on it, absolutly no need to be in the engine unless it's had some serious problems and looking at the pics more closely i reckon it has.
I think that the waterpump has gone and he's not noticed it, the coolant has mixed with the oil and the whole things overheated to the point that the cylinder has become damaged.
I'd be asking very specific questions about the engine, - why it's two different colours and why the waterpump cover has been replaced. tho to be fair i have heard of situations where the waterpump cover has been replaced in normal servicing, but that's pretty rare.
If he mentions cylinder wear as a reason for the differing colour of the engine, run away as fast as you can, the cylinders are nikasil lined so wear is not an issue, especially at that kind of mileage.
If he can't answer those to your satisfaction walk away.
just to balance it out a bit, i could be completly wrong and he's just painted that part of the engine black because that's all he had, but personally i'd still be wary about it.
on me
