I'm new to the CB72/CB77. On all the other vintage Hondas that I've worked, the starer chain is lubricated by engine oil.
On the CB72/CB77 motors, the starter chain and sprockets are in a "dry" part of the crankcase (i.e., no engine oil).
So, given the lack of engine oil to lubricate this chain, what type of lube should I use on it, and how often?
starter chain lubrication
Jas,
I'm no expert, but I believe the starter chain is oiled via slow-feed oiling at the right-side bearing of the crank which dribbles onto the starter clutch, and then to the chain. No periodic manual lubrication is needed. As proof this oil is flowing, my CB77 always drips a bit of oil from the right-side engine cover after I park it. Good luck with yours. Larry Is there any way that this oil is recovered and returned to the crankcase? Is it possible that you just have a leaking output shaft seal? Soichiro Honda despised oil leaks. I can't believe that Honda would have had any lost-oil lubrication on any of their motorcycles. Yes - a leaking seal.......
The chain is not lubricated. It is stationary most of the time. G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
Oops, my bad! Thanks for correcting my misinformation, G.
I guess is is just fortuitous that I have a leaky seal. I believe it is the RHS crank seal, as it migrates onto the starter chain, but wouldn't be surprised if the output shaft seal also leaks. As I warned, no expert here, just a long-time Super Hawk rider. Wish me luck, as I plan a 300 mile loop ride through the desert W of Death Valley tomorrow. I'll carry extra oil, although in truth, oil use is minimal for my 1963 CB77. Larry
OK, it looks as if my vague recollections had some basis. I recently had the need to get into my starter clutch, and found something about an oil feed to the clutch in my work manual. So, while there is no direct path to the chain, some oil can dribble out at a low rate.
Unfortunately, the image I have is too large to attach, but if you look at pages 167 and 168 of the Honda workshop manual (1960), it says this: "Lubrications (sic) for the over running clutch is done by oil dropped through the hole (A) in the figure which passes through the groove at three points (B) and starts inside of the inner oil seal 2035 of 20 mm bush and the lock seal 326575 to prevent burning. Therefore after disassembly it is necessary to clean oil holes (A) and (B) by compressed air." Hole (A) runs from a point in the cylinder above the RHS main bearing to just inside the RHS crank oil seal. (B) is not shown in the diagram, but I infer there are 3 grooves on the crank shaft allowing a small amount of oil to seep past the oil seal and then lubricate the starter clutch and chain. Was this an early design that was not retained in the production models, or is there such an oil path? Larry PS: the 300 mile desert trip was completed successfully, even though the 3 screws holding the starter clutch to the rotor were loose and caused a terrible schreech as one broke off and the head rubbed against the engine block. The schreech went away after a stop/start cycle and I made it home. To take some liberties with the Bard's words, all's well that ends. Larry
Interesting reading that. The oil path "A" is actually the feed to the RHS main bearing. I've never seen those three grooves "B". There is actually an oil hole through the crank which comes out at a drilling in the bearing surface where the starter sprocket bronze bearing runs. As this area is bounded by an oil seal on both sides the oil feed only lubricates the bush, not the starter clutch or chain. If it was not sealed the oil would get everywhere.  Glad you got home after your ride. Loctite or staking the screws should avoid your problem recurring. G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
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