Motorcycle Repair/CB77 1967
QUESTION: Hi Bill. It's me again.Hope you had good rides this summer.I am just back from a nice ride on my CB77.It is unusually warm for this time of year : 34C !I am experiencing a strange problem on my CB77 : if Ilet the bike parked for a while (say, 1 week), or if I ride it a couple of days in succession, the forkseems to pack-up, I.E: it becomes stiff and does not compress at all when encountering bumps on the road.The fork oil has the recommended CC's in it.I removed the fork caps, pumped the forks a couple of times,and put the caps back.Everything returned to normal.But, after a short while, the same things happens.I have done it 3 times, to no avail.Any idea what the issue is ? Also,my clutch slips when strating cold, but once the engone reaches it's normal oprating temperature, no more slipping.Is ther a current spring P/N that I can use to solve this.I only have CB72 NOS clutch springs, and they will not work.Thanks again.Michel
ANSWER: Michel, I just changed the clutch springs in my CB77 due to the same issues and used 22401-323-003 parts from the CB500F. The pull is a little bit stiffer, but not as bad as the 22401-275-810 spring sets.
The alloy Type 2 forks don't usually have sticking issues. You should be using 185-200cc of fork oil, probably something like 10wt should suffice. When they lock up, you might have to remove the front wheel and check each fork individually to see if one or both of them are exhibiting that kind of symptom. Seems like the only thing that could go wrong might be the snap ring coming off the end of the fork tube, but that wouldn't be a transient event.
In general, on the old bikes, the fender stays and mount systems are rather crudely fitted and can easily put the fork sliders in a bind, causing "stiction" and reduced fork response. Loosen up all the fender bolts and see if you can install the fender without having to force a bolt into a hole or having the bracket/stays be stretched into place. Get some 6mm or 1/4" flat washers and shim up any gaps where bolts might be causing the fender stays/bracket to be forced out of its natural location. You want the fender to fit the forks and not the other way around.
---------- FOLLOW-UP ----------
QUESTION: Thank you very much Bill.Appreciate it a lot.Will apply the solutions and let you know.
I saw that you have new guides published.I have the first issues.Is there new info in this last issue ? If yes, I will order them.Never enough professional info on these jewels.
Take care, ride safe.
Michel, all of the paper books which were offered circa 1992-2000 have been superseded by CD offerings packed with PDF files, targeted for each of the three 250-305cc offerings. The page count ranges from about 1200 to 2000 pages per CD, depending upon the model.
More details on my site.
Thank you for your purchases of my earlier offerings.