BSA B40 hard shifting.

[highboy_coupe]

Hello all,
I am now at the point  in the restoration where I can ride up and down the road!! Big step!
I have noticed however, that getting in and out of first gear is incredibly stiff (I can see  why those splines are worn!).
It is at about the limit of adjustment on the clutch lever, I can see the basket moving although it's very heavy to pull.
It just doesn't seem to want to change into gear without a lot of pressure on the foot lever.

The gearbox has been rebuilt  and the clutch has new plates/springs.

Thanks

[rhyatt]

The external actuating arm must be set correctly to ensure mechanical efficiency.
Ie, not more than 90 degrees when lever pulled in.

Have you set the clutch pushrod correctly

[highboy_coupe]

Hi, thanks. I haven't yet, that was on my list of jobs for today
There is a little free play at the lever, and the gearbox and clutch came to me assembled from a working (when it was laid up) bike so I stupidly thought I might get away with jumping on it and it working 100% perfectly.

[rhyatt]

Undo the clutch cable, open up adjustment cap on primary case, undo loch nut and screw adjuster screw in looking at the actuating arm until it points outwards or probably stops , then back off the screw 1/2 turn.
Refit cable and adjust to 1/8" free play.
Ensure oil in primary is correct grade and level.
Look at actuating arm when you operate lever , does it finish up at right angles to the cable

[Stevegayler]

Not sure if this helps but I have a 1969 B44SS. I had clutch problems and it looked as though it had the wrong length (shorter) springs fitted. I bought the correct length springs but could hardly open the clutch. If I released the pressure on the springs to allow the clutch to work, the clutch spring nuts fouled the chaincase. So I reverted back to the original springs.

[highboy_coupe]

Thanks both,  I have gone through the adjustment process a few times and it isn't really changing anything!

One things, the clutch arm on the crankcase, that does not move when I wind in the adjustment nut. It is 90 degrees to the cable when the cable is slack. The nut was won't pretty much in, but the feeling of bottoming out is vague.  On some bikes I have had, you assume that "in" is when you start to feel tension, so there would be some turning left if you tried harder.
I can make it more or less notchy by giving it more slack on the lever end, but it is always notchy. Again, this might just be the bike. It has sat for 40 years after the new clutch was put in!

[rhyatt]

The arm is a rack and pinion arrangement, so has to be be correctly engaged.
Mine moves outwards as I screw the adjustment screw in,
Do you have the correct length pushrod I wonder

[Stevegayler]

In addition to Rhyatt. Has the gearbox outer casing been off and the rack and pinion shaft not been positioned correctly.

[highboy_coupe]

Ahh, Steve I believe you are correct, the bottom end and gearbox was rebuilt back in 1980, it's been garaged since then but the previous owner is understandably hazy about the finer details, as a 20 year old lad he may well have put some bits together wrong.

It does now shift, it's just notchy.  Should I remove the side case and index the actuator? Will it cause any problems except a less than ideal pull angle?

Thanks

[rhyatt]

I feel that it may be worthwhile attending to the actuating arm angle - mechanically it it worth sorting correctly - plus for your sense of doing things correctly

it becomes self-evident when you get the outer side cover off - just how much of the rack and pinion needs to engage with the gear on the end of the actuating arm to give you the 90 degree when pulling the clutch in.

you can try it on and off a few times , just using 1 or 2 screws to hold the outer cover on before finally closing up properly.

give yourself some length on the clutch outer cover adjusting screw as well mine starts about 1 oclock - maybe 1-30 when I look down from above on the arm - give or take.

the operation will become very sweet mechanically and be a joy

use 40 or 30 in the gearbox(depending on time of year and I use TQF or ATF auto fluid in the primary to help the plates separate.
the BSA gearbox is a nice box - always was/is

[highboy_coupe]

Yes it'll probably drive me mad knowing it's wrong.. I suppose this means I must remove the points system? I will have a look in the book to check....but that took me so long to get set up correctly!!

[rhyatt]

if yours is side points (the same as mine) then yes

just mark the points plate to the outer cover with paint.
undo the 2 pillar bolts and the wire of course and remove plate - this gives easy access to the removal of the outer cover

if you do it on the side stand, this reduces the oil loss - you'll be topping it up anyway !!

Marking with paint facilitates 5he replacement procedure, and reinstating the timing

[highboy_coupe]

Hi all, got the side cover off. Now, a few things, is there a knack for getting it back together?

Should I make it so the pin bottoms out when the arm is at 1 o'clock? So if I push the pin on all the way the arm naturally stops at 1?

The Kickstart shaft is very tight in the outer cover sleeve , this necessitates putting the quadrant in place, hooking the spring over and then tapping the outer case on with socket, is this normal or just a corroded shaft?

It makes the whole thing a bit fraught as impossible to take the cover off again without pulling the kickstart out and having to start all over again!!

Thanks

[rhyatt]

You already have a starting point that you know where it finished up when the clutch was pulled in.
Therefore, you can disengage the rack and pinion and re-engage it to give you further travel , , May only need 1 tooth more.
Yes, my shaft was tight, so clean up everythingbefore reassembly, I used wellseal on the joint faces which works well

[highboy_coupe]

Thank.you very much, that would indeed be the case every thing hadn't fallen into the floor when I took it off... you live and learn!

I'm going to assume that it was fully bottomed out at 12 o'clock, as there was no more movement when the cable was off and I was about to disassemble.
Haynes manual and the service sheets seem to skip this bit, focusing instead on the generous greasing of the ball bearing.