The bike has been fitted with an Arrow 4 into 1 and a P C.......cant see this causing any issues ?
The mark on the piston is so tiny I doubt it could have cracked the crown..Its almost invisible...
I really dont want the engine pulled apart...if I was buying a used bike Id be very wary of one that looked like it had been apart...or is that just me?

It was not the valve guides.......randon bits of brass which, when laid end to end look (to myself and a few others) like a blade from a key.. Its being taken out of the workshop in the next day or 2 and going to Kwak in Valencia to try to work out what happened. How do I post pics of the debris found in the chamber? Might ring a bell with somebody if you see the bits..

post your images on a site like Photobucket or similar hosting site, and enter the url of the image in between a pair of [ img ] [ /img ] (remove spaces between the [].

Sounds bizarre though. What condition is the air filter in?

Ok thanks but between a pair of whats?
The air filter is good and in place although it was taken out at some point while in the shop. It has even been suggested that its a result of a deliberate act ....There is a Spanish guy in there who is insanely anti Brit ( and I mean steam coming out of his ears when we are in the workshop) but he is the father of the owner and I cant quite see him going that far...Job creation I suppose
Sick of it now..

Well ........just been to workshop and, despite me telling him not to, he has taken a piston out He wants to charge me 1100 Euro for 4 valves and guides and a piston (he is using the old rings) and claims a head gasket is 200 Euro. He also says the head need skimming which is total cr4p.
I can see this ending badly....

Anybody got an idea as to real costs for this work? Ill have to pay even though Im convinced it was their mistake..

I've changed my post now so you can see the image instructions.

No idea why they dissappeared.

Sorry to hear about the trouble you're having. Don't sound good.

The head shouldn't need skimming, unless it has had an overheating problem.
It is advisable to check it's flat, you can machine it flat by taking about 0.01-0.03mm off, if this leaves untouched areas, it needs skimming till it flat.

I'm rebuilding a Fiat 2.0 20v turbo engine at the mo, I've had to skim the head and it needed 0.34mm taking off due to distortion from an overheat.

The prices are very hard to predict, due to it being Spain. I know, my folks live there.
Some things are expensive, some things are cheap. The Euro has really changed things.

The rings should be changed with the piston, and the bore honed to allow it to bed in. Re-useing rings is a risk. They often get distorted when they are removed and can break if re-used.

Why not rebuild it yourself?

What aload of rubbish. Rip off or what. Engine didnt need stripping. Head doesnt need skim. Piston needs to be smooth. I do 2 strokes all the time. Polish and buff. If it comes out, then all is fine. A deep scratch isnt good.Saying this, thousands of bikes will have marks in a piston and run fine and safe.
On a 4 stroke the sump or bottom end is separated by the piston rings. These were ok. Entry by top end? dont think so. valve guides stop all. Spark pugs is a norm, but not in this case. Inlet seems the only entry but as someone said, its fuel injected. even with carbs, unless someting is thrown into the inlet post...hmmmm dodgy

One or two of the wellnuts for holding on the fairing (foreman grills i think) go right in to the airbox there has been mention of these being damaged and causing engine damage.

It could well be the garages fault if they have been too rough with them

http://www.bikeland.org/board/viewthrea ... genumber=1

Yep...it was a wellnut ! Strange name for something that lunched the bike!! Lots of parts to buy now