Motorcycle Repair: Oil seal, generator, CB77

Question
Hi Bill.With regards to my previous question : lean running condition, right cylinder, it turns out that the rubber gasket of the carb top was worned and the leak came from there.....Changed it and all returned to normal.Now, the alternator oil seal leaks, and needs changing before it oils up the stator.I have read somewhere that it can be removed and replaced without disassembling the cases.Is tat correct ? And if true, what is the procedure ? Thanks again Bill.Michel

Answer
Michel...

Well, there are two seals on the crankshaft end for a CB77. One is for the crankshaft that mounts in the engine case and the other one is in the starter clutch hub.
Michel,

Glad you found the cause of the lean condition. That's an overlooked part on the carburetors.

Regarding the questions about the seals...

http://www.cmsnl.com/honda-cb72-general-export_model14955/partslist/E12.html#res  #26
http://www.cmsnl.com/honda-cb72-general-export_model14955/partslist/E03.html#res  #24

You don't have to split the cases to replace either seal, but you will have to remove the muffler, left footpeg assy, kickstarter cover, stator, rotor, woodruff key, starter motor/chain and hub to get the seals out. You do need the special 16x1.0 mm rotor removal tool to get the rotor off the end of the crankshaft snout. While the rotor is off, it is a good time to refresh the starter clutch roller springs/caps/rollers as necessary so the electric starter system can work efficiently.

Pry out the old crankshaft seal being careful not to damage the edges of the case or nick the crankshaft. Start the main crankshaft seal in easy, a little at a time, keeping it squared up and using plenty of lubrication around the outer edges and the seal lips. Starter clutch hub seal just pops out and you can install it with your fingertips.

Set aside about an hour to go through it all and put it back together again.

Bill Silver