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Motorcycle Repair/Oil seal, generator, CB77


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


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.

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

Regarding the questions about the seals...  #26  #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

Motorcycle Repair

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Bill Silver


Need help with vintage Hondas from the 1960s? I am an expert with 250-305cc bikes in particular and most all of the other pre-91 models, in general. I do NOT claim to have a great deal of experience on Gold Wings, Cruisers, ATC/ATVs and dirt bikes.


I have owned/ridden/maintained Honda motorcycles for 35 years. I have written five books on Honda repairs and collecting. I was a service manager for two Honda shops back in the 1980s.

VJMC (Vintage Japanese Motorcycle Club) of North America

VJMC newsletter, as editor for two years and as contributing editor currently.

3 years auto shop in high school, teacher's aide in Automotive Technology in Jr. College, Diesel mechanic course in college, self-taught mechanic and automotive writer.

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