Havent been on here in a while so an update to where the bike is.
Contacted BMW Mottorad customer services, they didnt give a monkeys, not even a slight bit of interest in what had happened, why it had happened or how it was going to be fixed....bounced it off them a few times, different letters, different people......and they just didnt want to know.
In my opinion I was left quite pissed that a company such as BMW took this stance. I even asked if they would provide me with spare parts at cost (without theyre very generous mark ups) and even that they werent prepared to budge. Dissapointed in BMW and they have now lost my faith. I know technically they didnt owe me a bean.....but with a bike with not many miles on and full BMW service history i at least expected them to show an interest.
Am still planning on taking it higher and seeing what happens (Ive got nothing to loose). But please all take note off BMW's attitude towards such matters. This was a major engine component, not a small consumable/wear and tear kind of component.
I removed the head and pushed the pistons out of the block.....no damage to the bores they look absolutley fine. Head and valves all look good as do the pistons (apart from needing new bearing shells in their associated con rods).
Looked around for someone to replate/grind the crank....no-one around who could do it...... plus I found a second hand (very good condition) for £150.
Priced up the parts i required, with New bearing shelld and stretch bolts, and used crank and balance arm assembly...price was coming in at £650 (with a discount!)
The engine being advertised on Ebay Italy was up for sale for 1200 Euros plus 150 Euros shipping.....i Managed top get it for 1200 euros all in including shipping, so just under £1000.
Engine arrived, is now in the bike all is running and at the moment all is good.
Please note, when i first took the bike out for a spin with the new engine (very carefully) I noticed there was a big flat spot in gears 3 and 4 at mid range through the revs....almost like the bike was hitting the limiter.....but obviously it wasnt......power on through the flat spot and the bike would start pulling again etc. Got me quite woried and I hastily rechecked the valve clearances etc.....however I since learnt that having the battery disconnected for a few weeks will reset the ECU....... the throttle position sensor (TPS) are 'automatically' adjusted on the F800GS' and basically set themselves....... someone mentioned a few hundred miles of riding and the flat sots dissapear as the TPS corrects itself.
I have only done 50 ish miles since the new engines been in and already it is smoothing itself out and the flat spots are no where near the size they were....... ill keep you updated if it resets itself.
Back to the original engine; I see myself having two choices. 1. sell the engine off as broken down spares... think I should be able to get £500/£600 quite easily (maybe more)
2. Wait for cheap used crank and balance arm to come up on ebay, rebuild the engine and sell as a complete engine.....(if i do this i will sell with the invite of helping, for free, the buyer fit the engine to their bike so that i am happy i am selling them running engine with the guarantee that if it doesnt work ill take it back and refund complete).
At the moment im holding fire on either option and just making sure that the new engine is completely fine.
By the way.....I found putting the engine back in much easier than taking it out....with careful tagging off all the loom connections, photos and a good mecahnical mind it was quite easy. If I had to guess times, I'd say it took me 8 hopurs to strip (from complete bike with fairings) the bike down and remove engine....and probably 5/6 hours to put a new engine in and rebuild the bike back up. I had my dad help me 'steady' the engine as i was jacking it back up and into the engine...... possible by yourself but easier with two.