Motorcycle Repair: gixxer engine noise, clutch gear, starter clutch

Question
Dan,I have a knocking sound that comes from the alternator on my 87'gsxr750.I listen with a stethoscope at the cyl. the crank case,starter & clutch covers ect.I removed the alt.and still can hear the sound but not as loud.I pulled the motor & the lower crankcase to plastigauged the bearings.The rod bearings were in spec. but the mains were slightly out at .51mm.My question is mostly about the info in my clymer manual.Is 18 ftlbs correct on 8mm(mains)crankcase bolts? Is the oil clearance spec. the measurement i'm checking? Is there a backlash spec for the clutch-gear to crankshaft-gear & if so how do you correct it?(it seems to mesh tight in on spot)I'm thinking this could be were the sound is coming from.Thankyou for your time! Danny

Answer
I think that you  dug too deep into your problem.You are on a good track.I am not there but the knocking noise that you hear might be cause by something else.does it get worse when the engine is revved or does it go away?When was the last time that the cam chain and tensioner was looked at?I also had this problem but it was on a 94, and it was the cam chain and tensioner,and the noise that you might be hearing is the chain slapping, examine the tensioner and see if it is working properly.As too you clymer manual and the spec's that they give you is pretty much the same as a suzuki manual minus a few things.on the mains you were checking the oil clearance.