As said^^, Were there any adjustment to the valve shims on that head? Seems likely as that's to much of a coincidence imho, Just a thought, Possible to mix the caps up etc??
yip. hear yah. its a tuffy to know which way to go. going wrong twice? v,unusual. not knowing the full ins and outs of what was agreed between the garage and owner i wouldnt commit on here. and yet another reason why i wont suplly used parts.
Looks like the broken belt is a consequence of the cam seizing. Did you see the belt? Was it snapped or shredded? There are two easy ways to get a shredded belt on these engines, first is to rotate the tensioner the wrong way, as has already been said. Second is to fail to seat the top hat spacer in the tensioner pulley properly. That bearing journal suggests the broken belt was a consequence, not the cause though.
in my head, i'm not. buuuut. after thinking about it, if it happened in here and i promissed all would be well after the 2nd visit and supllying a used part. i would take the hit and learn from it.
Hence the question. Without all evidence, no one can say what caused what, what was or wasn't done correctly.
as above, depending on how much has been dismantled*, can you take and supply some more pictures for us please @adam_pl ? anything you think might be relevant, the inside of the (front/nose) cam cap, the idler/tensioner assys if still fitted, the belt(s) *who dismantled after the second failure? a bit late to say but pictures taken prior to this are or could/would have been vital to try and determine what happened.
I'll get to the workshop tomorrow, check it and see if I could take some pics. It'll be dismantled tomorrow, after second failure, by the same workshop.
This probably goes without saying but if they have expressed concern and possible responsibility already regarding the failure(s) then obviously tread carefully as regards taking pictures, but if it looks like there’s a good chance you are footing the bill then pictures are vital to be honest.
ok, I've just talked to the guys. It results that the belt is intact. They told me that when the bike came, they've checked it and started normaly (when cold). after removing head cover and checking camshaft they realised that there is the same problem on the same cylinder. this time there are no scrathes on the surface but there is small bright spot on a camshaft (pic below). looks like it was starting to seize and engine stopped. So there is problem with oil distribution when it's hot. I wonder why they didn't check the oil pressure after first failure. It could be oil pump, valve in oil pump or something stucked somewhere. Any ideas?
Just a thought..... they are meant to be the experts and should be telling you why this happened. If YOU tell them, then you are setting yourself up as liable in future. Good to be curious though.
Because there will be enough oil from the assembly process to keep it running for a few kms. A good mechanic will smear oil on parts so you do not have dry parts running together..
I agree but the photo of the head we have seen appears to show a seized camshaft. We'll have to wait to find out the cause of the second failure. The camshaft caps are meant to be coated with Molycote M55 Plus on refitting.
Cannot see it is oil pump related as the rest of the engine - cams, big ends are ok? Looking at the photo of your cam journal there seems to be traces of sealant ( three bond?) on the mating surface, if this has got squeezed out and into the oil feed hole then it could explain the problem. Also bit confused as to why half of the bearing journal is mashed and the other half is fine? Personally I'd start in this area looking for something that shouldn' t be there like excess sealant.
