QuestionBill,
I recently bought a 1973 Honda CT 90. It has several issues, but the one I'm most perplexed by is the shifter/transmission. It has the centrifugal clutch.
When I got it, it seemed to shift pretty hard. I followed the instructions in my Clymer manual for adjusting the clutch. It was at least two turns out of adjustment.
Once I was done, it was, if anything, even harsher than before. I have the bike partially apart working on a carb issue so I can't test it, but I did notice the oil was pretty low (probably a pint). I filled it up, but don't know whether this will improve the shifting.
What else might be going on, or is the oil likely the cause?
AnswerTerry,
First, some of the Clymer's books have wrong info in them. So, just in case, I am pasting in the procedure from the Yahoo Groups CT90 site:
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From: ct90@yahoogroups.com [mailto:ct90@yahoogroups.com] On Behalf Of
Keith Wollaver
Sent: Friday, January 20, 2006 9:24 AM
To: ct90@yahoogroups.com
Subject: Re: [CT90] Clutch Adjustment
Hi Bob-
Here is what Nate says:
"As far as clutch adjustment here goes : bike on center stand , in neutral , you'll need a 14 MM box and wrench and a narrow flat blade screwdriver that fits in the screw slot without touching the sides of the nut ~ this is very important so check your tools before you begin ! using an open ended wrench _will_ cause you to ruin the nut
and gouge up the side cover too so DON'T try it ~ no offset 14 MM box wrench ? not to worry ~ get a 14 MM socket and a pair of Vise Grips ('Mole Pliers ' for our British friends) and clamp the Vise Grips onto the socket ~ presto ! now you have a box wrench and can proceed .
Loosen the 14 MM nut one full turn , now take the screwdriver in your finger tips and gently try to turn it _counterclockwise_ ~ it won't go ? not surprising , turn it _clockwise_ until it gets loose then turn it _counterclockwise_ until you feel resistance , very
little resistance , stop and turn the screw _clockwise_ 1/8 of a turn but NO MORE . now tighten the nut whilst holding the screw from turning , look at the position of the slot and if it moves , stop and do it over .
Now go ride your bike , the kick starter should spin the engine much better and it'll prolly take up in a day or so so expect to re-adjust as needed until the clutch beds in again and stays in adjustment ."
"It is critical to hold the adjusting screwdriver very gently so you can feel the very instant it bottoms as you're turn it_counter_clockwise , then stop , turn it 1/16 ~ 1/8 turn _clockwise_ and then_HOLD_ it right there as you use a _BOX_ end wrench to tighten up the lock nut ~ failure to hold the screw means bad adjustment as it_WILL_ creep as you tighten the lock nut...
I personally like to adjust the clutch with the engine running @ idle speed , fully warmed up ."
Keith in AZ.
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Yes, the engines need oil for the clutch function, as well as lubrication for the rest of the internal parts. Keep it between the two marks on the dipstick, bike on centerstand and dip stick Dipped in, NOT screwed in to check level.
Other possibilities... Clutch parts are worn out and/or the clutch is partially seized from sitting for a long time. Steel and fiber plates will rust together and even when they are separated, the roughness left behind on the steel plates will cause the clutch to drag.
Note: Shift lever does dual-duty by releasing the clutch at idle speeds, when pushed either direction, and then selects the next gear at the same time.
Bill Silver
