The cylinder stud o-rings showed up last week - I was going to paint the fenders and side covers but the weather took a dump today so I turned attentions to the motor. Deep breath, round two. New OEM base gasket, no dicking about with jobber shite this time -
The OEM cylinder stud o-rings are a considerably different size to the jobber ones (OEM on the right) -
Piston ring gaps all in the right places, lowered the cylinder block - without an extra set of hands lying around I use cable ties on the outer studs to help hold the block in place -
Ease it down over 2 and 3 pistons at TDC, everything going swimmingly -
until the motherf*cking bastard of a sh*t sucking f*ck knuckle w*nk tw*tting cam chain tensioner acorn nut fell into the lower case when I was loosening it. Bad fucking scene. Even worse because I did the exact same thing last time, except that time it was the washer. Turns out the washer is worse to dig out - it's lighter and not magnetic. Still, had to drop the pan and mercifully the little shite was in there. Anyone reading this working on a CB750 engine - don't do what I did, twice. Thread the upper acorn and washer onto the tensioner thread, leave the lower one off until the cylinder in seated. That way you can push the tensioner inside the lower case as you're lowering the cylinder (it won't clear if both acorn nuts are tightened) , and then thread the lower nut once you're done.
Bollocks.
However -
When I dropped the pan I was that there was a bunch of aluminium shavings in there too, not chunks but tiny shavings. I
think they've come from one of the cam holders - I switched out the 750 cams for 900 cams and maybe there was a slight clearance issue - on inspection one of the holders is definitely a bit scarred. Cleaned out and re-installed the pan, got the block installed, with the correct head gasket this time -
then the head and then torqued up the bolts to spec.
Praying that ally in the pan was from that cam holder.