bhs@siemens.UUCP (04/19/85)
I am the proud owner of a 1977 Honda 750k. I ride it relatively hard and have
equipped it with appropriate accessories(Konis, jets, Jardines etc). Lately,
when shifting gears at high rpms, something seems to be grinding in my gear-
box. This happens only at high rpms consistently. Could my original clutch
be going or might something be wrong with the transmission.
I would appreciate any information regarding this problem. My dealer could
not help me at the price I was willing to pay for him to troubleshoot.
Also, congratulations are due: this is my first contribution to the net!
Stevekehoe@reed.UUCP (Dave Kehoe) (04/27/85)
Excuse me for posting this to the newsgroup rather than replying
directly to Mr.Siemens, but I suspect that other users would like
to know the basics of troubleshooting a transmission problem.
I won't quote his article, rather I'll go directly into mine.
I know a fair amount about motorcycle transmissions,
having put a new one into my 1972 CB450. To help you, you'll
have to describe your problems more clearly: "something seems
to be grinding" doesn't say much. Does your transmission:
1) not go into a certain gear?
2) slip out of a certain gear? (The RPMs will suddenly shoot up.)
3) Is the problem with one gear or all of the gears?
4) Does the clutch not fully engage (i.e. slip when riding hard) or
5) Does the clutch not fully disengage (i.e. in first gear, with
the clutch lever pulled in, the bike shouldn't creep forward)?
You say that the problems occur only at high RPMs. That implies
that something may be loose -- engines vibrate *a lot* at high RPMs
and so anything that's not bolted down very tight will move around.
If the problem occurs with a certain gear (e.g. 2nd, or 3rd),
then the problem is in the transmission. You'll need a new pair of
gears, a new shifter fork, maybe a new shifter drum. I.e. $100 and
a long weekend of work.
If the problem occurs in all gears, the problem is not in the
transmission, but in the gear shifter or clutch. Both are easy to
work on, and a new gear shifter is cheap (~$20). I'm not sure what
new clutches cost, but installing one shouldn't take more than an
hour or two.
My guess is that you need new clutch plates, but that's just
a shot in the dark until you describe the problem in more detail.
Have you tried adjusting the clutch?tatge@hpfcms.UUCP (tatge) (05/09/85)
Yes, your original clutch could definitely be going or even gone.
Also, you could have something wrong inside the case. If you do
not want to hand it over to the dealer to fix then it is time to
buy a shop manual, a few special tools and start digging in to it.
Start by pulling the clutch and checking the plates and springs.
The shop manual should have specs for warpage and wear limits, in
addition to the obvious visual checks for cracks, breaks and scars.
Chances are you'll want to replace the friction plates and springs
at the very least. If this doesn't help it will be time to pull
the engine and crack the cases. Take your time, keep it clean
and make lots of notes on where everything goes. It really isn't
that difficult if you keep it organized and sanitary.
George Tatge
Fort Collins, CO
ihnp4!hpfcla!tatge