Clunky shifting B12

[China Greg]

I've got a wonderful, black, '98 B12 that functions great... except for sort of sloppy shifting characteristics.
This is my second B12; the first shifted great. I bought this (second) bike with only 1800 miles on it... so I'm surprised it has any shifting concerns, but okay.. that's it.

Going from first into second and third, it's not SMOOTH. Sort of hesitates before resleasing the clutch, so that fast shifts end up ... missing.. a little. Just enough to be annoying.

My local shop guy says you have to split the cases to get the shift-shaft out. Can't do it from behind the clutch basket. Crap.

Anyone got ideas or feedback?

[Red01]

Have you tried a different oil?

The miles seem awful low for trouble, but I guess a clubfoot could have bent a shift fork.

[mademiriam]

I guess a clubfoot could have bent a shift fork.

Just when I think something is nearly impossible...somebody has probably done just that.
I agree with the oil idea, worth a shot for sure...also this may sound odd, but are you comfortable with the position of your shift lever? I've found that on some bikes I need to adjust it so I can feel that nice positive shift. Just brainstorming really, splitting the case would steal some riding time.

[China Greg]

Well, I suppose I COULD try another oil... currently using Bel Ray semi-synthetic 10W-40... but I don't THINK that's it... uhh..

This condition has been there ever since I bought the bike SHINY, with 1800 miles (now has about 14,000), so I'm guessing some ignorant Magilla Gorilla stomped it too hard after stalling at a light or something.
As a matter of fact, the previous owner WAS pretty much of a Moto-Dummy, and sold me the bike way cheap ($3000) because he thought it had "some problem"..(at first tried to hide the fact that it was only running on three cylinders).Turned out that the bike had sat for a year in his garage, and I immediately diagnosed GCS ... Gunky Carb Syndrome. I pulled the bank off in his driveway, hosed the bowls out with carb cleaner, had it buttoned-up in about 40 minutes, then rode smoothly off towards the New England Turnpike, percolating nicely. His jaw was hanging...

Anyway, I would guess shifter-fork damage of somekind. That's what it most feels like... a very steady and predictable "glitchiness".

My question now is:
CAN YOU GET THE SHIFT-SHAFT OUT OF THE BIKE WITHOUT SPLITTING THE CASES?

One Zook mechanic here says Nope, the forks will drop down inside..... so now I'm thinking, hey, what if I carefully pushed a DOWEL through from the shifter side, thereby (hopefully!) holding the innards together, then push a new shift-shaft back in?
Huh? Whaddya Think? Huh?

[swagzz]

what if I carefully pushed a DOWEL through from the shifter side, thereby (hopefully!) holding the innards together,
   Hi China
 sounds like a plan BUT if it does drop  :duh:you are going to have serious  fun fixing it but nothing ventured nothing gained.
  i'm going to watch this space with some interest ( might have to do this myself sometime) and i think it will be very very very carefully pushing the dowel.
                                                             Later swagzz

[China Greg]

Yeah, I'm headed over right now to take a GOOD LOOK at my manuals...
I suppose if it DOESN'T work, I'll be ripping the motor out of the frame and splitting the cases.

Might give me that excuse I needed to have Dale Walker work my cylinder head.

[Red01]

Now there's some positive thinking... 

[pmackie]

Well China, youv'e peaked my curiousity as well. I'd be interested to see if you can access the shifter fork shaft from behind the clutch, but I doubt it, and I'm pretty sure the shaft does NOT extend through the left (drive) side case. You might be able to drill it, but then you would need to plug and seal it when done.

But, the more I think about this, it is unlikely, IMHO, that the shaft that holds the shift forks is damaged, it is much more likely a bent shift fork, damaged gear dog, or shift drum issue, based on your description.

If you have a bent shift shaft (that connects the shifter to the pawl that turns the shift drum), you should be able to replace this without splitting the cases, but this usually shows up as very stiff/hard shifting, in all or most gears.

Let us know what you find.

[China Greg]

According to my Haines manual, just read:

"IT IS NOT NECESSARY TO DISASSEMBLE THE MOTOR TO REMOVE THE EXTERNAL SHIFTING MECHANISMS".

...which I take to be very promising news, but I have to study the diagrams more carefully.

Yes, the problem DOES in fact seem to be "hard shifting"... or maybe better, "sticky" shifting... and I'm willing to bet the price of a new shift-shaft/pawl assembly whatever (plus my labor), that the problem is indeed EXTERNAL. Here's hoping.... keep your fnders crossed for me. More results in a week or two, after I order, receive, and install parts.

Any comments/help/derision in the meantime highly welcomed

[Bob Holland]

You can remove the shift mechanisim by removing the clutch basket, but not the shift forks or shift drum,
for that you must split the cases.

[China Greg]

Right... it seesm to be that the shift-shaft and shift pawl mecahanisms are removable from behind the clutch basket. Drums and forks are internal pieces.

NOW... the question for me is WHERE is the problem?
In a smooth-shifting bike, you can do Power Shifts...leave the throttle on to some degree, and fan the clutch in while shifiting.
Or, put some pressure on the shift lever, roll off the throttle for an instant, and do a smooth clutchless shift. My little Honda CB400F can do this amazing smoothly.

The current B12 I have will NOT do this smoothly, and requires a very  pull on the clutch. Often the feeling is "notchy" between gears, making it important to make very DEFINED actions, PULL.... SHIFT..(ka-chunk)... RELEASE. Won't snick smoothly like previous bikes I'va had... including my previous 1st Gen B12.

[swagzz]

hmmmmmmmmmmm


clutch
   


lever on left
 

useful for takeoff


downshift


flicking a little to get it to stand up

 waiting at traffic lights


stopping  and changing up in a leisurely fashion (usually when constabulary are about)




no help in solving the ka-chunk bit tho and everyone always wants some serious head work

[Dragbike]

You can remove the shift mechanisim by removing the clutch basket, but not the shift forks or shift drum,
for that you must split the cases.

Well I guess I have been working too many hours lately and a little fuzzy and did this 7 years ago. But If I remember right (on my Katana 1127) All I did was pull the motor turn it upside down, pulled the oil pan, clutch cover, and I had the whole tranny on the table in about 30 mins I checked my rods and crank but never had to split any cases or even take any other covers off.... or starter or alt and ing. still bolted on.  Not a big deal if you can lift the motor by yourself on the table. Forks, shift drum, and second gear goes pretty fast on a air shift (stock tranny) dragbike. And there is a way to open up the inside of the cases so a person can change a shift fork with out pulling the motor, I just never wanted to releive/cut my cases to do that. Funny bike guys with auto trannys change forks in between rounds all the time.
Let me get some sleep and think about it some more.
Brent

[China Greg]

Wow, Brent, that's some solid info... and good news, excpet for the fact that I'm considerably SLOWER that a Funny Bike drag mechanic... and it would probably take me DAYS to get it done right. Lessee... new exhaust gaskets.. clutch cover gasket...oil, filter...

But maybe YOU can give me an idea o where to look for the shifting problem I have, (sort of notchy between gears.. especially down in lower gears):
Internal
or
External
Shfiting mechanisms?

I just ordered a shift shaft, shift pawl assembly, shift-shaft spring, and a (leftside) shift shaft seal. All for about $72.

IF necessary, I will do as you say, and rip out the motor and crack the pan... but geeez... it looks so PRETTY and SHINY sitting in there all comfy and all....

[Bob Holland]

You can remove the shift mechanisim by removing the clutch basket, but not the shift forks or shift drum,
for that you must split the cases.

Well I guess I have been working too many hours lately and a little fuzzy and did this 7 years ago. But If I remember right (on my Katana 1127) All I did was pull the motor turn it upside down, pulled the oil pan, clutch cover, and I had the whole tranny on the table in about 30 mins I checked my rods and crank but never had to split any cases or even take any other covers off.... or starter or alt and ing. still bolted on.  Not a big deal if you can lift the motor by yourself on the table. Forks, shift drum, and second gear goes pretty fast on a air shift (stock tranny) dragbike. And there is a way to open up the inside of the cases so a person can change a shift fork with out pulling the motor, I just never wanted to releive/cut my cases to do that. Funny bike guys with auto trannys change forks in between rounds all the time.
Let me get some sleep and think about it some more.
Brent

I can assure that if you got the tranny out, without splitting the cases, you broke something.
The Trans bearings are held in placed between the cases, the bearings have a dowell pin and a C ring to hold them in a presice location. They will not come out without taking the cases apart.
I have looked at the shift forks and shift drum and thought that they might come out without splitting the cases, but never had a reason to try.