Motorcycle Repair: 1977 honda cb750k, honda cb750k, roller bearings

Question
Bill i have two questions,I will appreciate you answering either  question i have oil in alternator housing should it be there.I have this engine dissembled because it had a noise in it.I have checked the cam chain and primary chains they seem to be ok.The noise didn't,t seem to quite as bad when the clutch was pulled in.It makes noise in gear and in neutral its kinda like a chain noise or bearing.what in the transmission would make this noise,

Answer
Don....
First answer,
The CB350-400-500 fours all have sealed alternators, with crankshaft seals, so no oil can pass from the crank to the alternator. The CB750 design doesn't provide for isolation of the alternator from the oil system, though.

Second answer..... Depending on the mileage, probably the camchain tensioner rollers are hard as a rock and skipping across the slackened primary chain. Check the clutch outer hub to shaft clearances to see if there is significant clearance between the two parts. Take a close look at all the ball and roller bearings for signs of wear/contamination/damage.

One of the big noise makers in the SOHC engines is due to the primary chain slap when the cylinders are not all balanced. If there is significant variations in compression readings between cylinders or improper ignition timing between 1-4 and 2-3 cylinder sets or carb synch issues, then the engines tend to have a decent rumbling sound down deep in the cases.

Bill Silver