Top end tear down advice please... 82 XJ 750

Hey All!! I finally did it and pulled the head and cylinder off.. I had a very scary sound coming from the engine that sounded like maybe a piston seizing? It came from the cylinder area and was at idle and went away when driving. A scraping/screeching sound.. Sadly I did not find anything that really pointed to what the noise was once I had torn down.. I was thinking a Piston was starting to seize?? Any suggestions/recommendations would be great! Does anyone know how much slack is supposed to be in the primary chain? Planning on deglazing the cylinders and putting new rings on. I really wish I knew what the sound I was hearing was!!!! Cam journals did not look perfect, but they looked pretty good. Timing chain seems to be OK? 25,000 miles on bike.. Any and all suggestions/recommendations would be highly appreciated. I will be making a call to Chacal in a week or so for my parts list order.. Take care and ride safe!!!!!!

 

did you look inside the alternator?

 

Hi mate, I’ve just rebuilt my engine and also had a rattle, the problem was the primary chain. Check this link and my other videos,

The primary chain should not have much if any slack in it. Seems to be a common problem...it’s noisy at idle and goes away under load as the chain tensions in a way where the slack pulls away from the oil nozzle which is what it could be generating noise from.

 

No I have not checked the alternator; and yes Mezzmo I have seen your videos and am a big fan!!!!! I don't have knowledge or resources to split case, so I hope and pray it is not needed. If I put my fingers in through the case I can feel about 3/8" slack in primary chain?? Thanks for input gentlemen!!!!!

 

Hmmm, with the head off can you check the top section of the primary chain doesn't have enough slack in it to hit the oil nozzle? If it clears then its unlikely to be the problem. Or, if you can see the oil nozzle and there is no wear mark from the chain then all good.