When I kick over the bike, I can feel a rhythmic resistance to the lever movement. It doesn't go away when I pull the clutch lever in, but just becomes more obvious as I'm not also feeling the resistance of the engine. I thought it might be the kickstart ratchet, (the frequency of the resistance was about right) but that seems fine, apart from the pinion being a bit slack on its bush. The kickstart quadrant is almost new and looks okay.
Since I discovered this, I haven't been able to get the bike to start. I'm not sure, but I think that at least once since I noticed this problem I was able to easily kick the bike over top dead centre, without using the decompressor.
As you might have guessed, I've taken the gearbox end cover off, but all seems well. What do I look at next?
I would pull off the primary cover and see if the outer clutch plate or clutch basket has a wobble when you kick it over with the clutch lever pulled in.
Another possibility is a gear box main shaft bearing problem.
Thank you Jim S. I shall remove the primary cover and have a look.
Hi Rog1
Let us know what you find.
Regards
Jim
Jim S. and all, I finally had a chance to have a look at the bike yesterday, and here's an update.
All was well under the primary cover, so I did what I should have done earlier; rotate the mainshaft via the nut on the right hand end. Not a trace of the problem, so I removed the ratchet and pinion assembly for inspection. Once it was all degreased I found the teeth on the pinion were worn on the tooth face and tip, and a bit burred over. The kick start quadrant, which was replaced recently by the previous owner, show a little wear on some of the teeth, on the side nearest to the bike centreline when it's all together. I could possibly file back the burrs on it and it would be okay. He didn't replace the ratchet assembly when the new quadrant went in. I think it was the burrs rubbing that caused the problem.
The ratchet pinion sleeve the ratchet pinion turns on is worn enough that there's about 30 thou clearance on the diameter between the two, which might be a factor if it makes the pinion sit or run at an angle. The ratchet is worn on both the ratchet pinion and the splined part of the ratchet. The spring seems fine.
I don't think the bike's done more than about 150 miles since the quadrant was replaced, and all was fine when I bought the bike; I'd done about 75 miles before this problem arose. The ratchet pinion, ratchet, and ratchet pinion sleeve obviously need to be replaced, but I'm not sure if the kick start quadrant also needs to be changed.
The previous owner did tell me about replacing the quadrant, but I can't remember what was wrong with the old one. I'll probably see him on Wednesday and get the story again, and I may gain some enlightenment then. There are no hard feelings involved.
Sounds like you found your problem.
Sorry I lead you down the path to remove the primary cover although if you want to be extra sure, you could remove the primary chain, then spin the gearbox main shaft by hand to ensure there is no resistance.
One note, you say you degreased the pinion and ratchet. I'm not sure there should be grease in this area.
Jim S, no worries about removing the primary cover; I got there in the end.
Instead of removing the primary chain I kept the decompressor lever in the open position with a bungy when I turned the mainshaft. No resistance (rubbing). Popping the outer gearbox cover on and held with a few of the screws, then using the kick start lever with the decompressor lever held in again: rubbing occurred, the culprit was revealed.
I meant degreasing in a more general way, the ratchet assembly was just covered in oil. But I saw that a few other items had been greased when I took the cover off, like the kick start pivot.
At last, I've been buying bits for the repair. The kickstart pillion has arrived, but it isn't the best made spare I've ever seen. I'm used to spares for Japanese bikes been very well finished, but what do you folks think of this one?
if I had cut one of those on our old Sykes we had it would have gone straight in the skip, I suspect made in the sub continent now.
Best to look elsewhere, then. Pretty much as I feared.
This photo compares the old one and the new one. there's a big difference in the diameter, which I put down to wear.
I finally got all the bits and installed them, (except for the ratchet, because it annoying didn't fit on the shaft) put the cover back on, and tried the kickstart. The original problem is still there. I took the cover off, put more oil on the gear, replaced the cover. No change.
the problem seems to be related to the gear teeth on the kickstart quadrant, and so to the teeth on the pinion. Does this all look okay in the photos? Please note, this is the old, worn pinion in the photo; it's just propped there to show you the way the teeth on each part compare. This old pinion and the new one seem to have the same shaped teeth, allowing for wear.
just wondering as the condition of the teeth looks flakey that the gear has been heat treated that is why it wont go on your shaft either.
Hi Rog1,
The image that you posted of the 'new' pinion is quite concerning. It looks like a knackered one. Where did you get it from and how much did it cost?
Is it the same as in an A10? If so, then SRM have some that look quite good. About £30 I think but better a bit more expense than a catastrophic failure. Also, C&D Autos will probably have them.
Dave.
I have just had a look at couple of kickstart quadrants, A65 not M33, but I think the tooth profile would be the same and the one in your photo looks to have teeth squared off like a gear pinion whereas the ones I looked at are more pointed like the pinion. Could this mismatch of tooth profiles be causing the noise?
Quote from: chaz on 22 Mar, 2020, 15:42
just wondering as the condition of the teeth looks flakey that the gear has been heat treated that is why it wont go on your shaft either.
chaz, this is the old, worn pinion, not the new ratchet.
Quote from: DAVE BRADY on 22 Mar, 2020, 15:59
Hi Rog1,
The image that you posted of the 'new' pinion is quite concerning. It looks like a knackered one. Where did you get it from and how much did it cost?
Is it the same as in an A10? If so, then SRM have some that look quite good. About £30 I think but better a bit more expense than a catastrophic failure. Also, C&D Autos will probably have them.
Dave.
I have just had a look at couple of kickstart quadrants, A65 not M33, but I think the tooth profile would be the same and the one in your photo looks to have teeth squared off like a gear pinion whereas the ones I looked at are more pointed like the pinion. Could this mismatch of tooth profiles be causing the noise?
No, this is the old pinion, just propped there for comparison purposes. The replacement (now fitted to the bike) seems to have the same profile as the worn one once did.
Regarding the tooth profile, I did wonder if the profile was correct on the quadrant, as it doesn't seem to match even the new pinion. I think you may be right. Having now looked at the one on the Dragonfly website (not that they can supply them presently), the teeth are not squared off; as it's a rusty one I should think it's an original part, so is correct. The quadrant I have on the bike was fitted by the previous owner a couple of years back, but he hadn't done many more miles on the bike when he sold it to me. Funny thing was, it was alright for the 75 miles and numerous starts I did on it before this problem arose.
I shall have to find another one. Thanks Dave, and all others who commented.
Hi Rog 1
I have a 1949 B33. Attached is a photo of the kick start pinion. You can see that the teeth are quite pointy. I believe this facilitates engagement with the kick start quadrant.
Your pinion appears to have a shape closer to a spur gear that should be permanently engaged with a mating gear.
Jim
Good morning Rog1,
Assuming that the image that I have attached is the one you posted as your 'new' one I would be bit concerned about using this. Comparing with a couple of used ones that I have, it looks like it does not have a good finish. Although it may not be, it looks very rough and brittle and would probably cause excessive wear to any new kickstart quadrant that you fit
Dave.
Quote from: Jim S on 26 Mar, 2020, 02:50
Hi Rog 1
I have a 1949 B33. Attached is a photo of the kick start pinion. You can see that the teeth are quite pointy. I believe this facilitates engagement with the kick start quadrant.
Your pinion appears to have a shape closer to a spur gear that should be permanently engaged with a mating gear.
Jim
hi Jim
the pinion in the photos with the quadrant is the old, worn one. The tips of the teeth have worn off. There's another photo on this thread that show this old one, next to a new (but not very good) one. The quadrant's teeth are square ended, and don't (I realise now) match the pinion's teeth.
Roger
Quote from: DAVE BRADY on 26 Mar, 2020, 07:29
Good morning Rog1,
Assuming that the image that I have attached is the one you posted as your 'new' one I would be bit concerned about using this. Comparing with a couple of used ones that I have, it looks like it does not have a good finish. Although it may not be, it looks very rough and brittle and would probably cause excessive wear to any new kickstart quadrant that you fit
Dave.
Hi Dave
I ended up getting another pinion which was rather better, though to be honest I didn't think it was brilliant. There are no photos of it.
Roger
I thought I'd updated this thread with the final result. I hadn't, so I'll do that now.
I bought a used, but good condition quadrant from a chap in rural France, on Ebay. I put the bike together, but the problem remained. A local rider who has had BSAs for years tried it, pronounced it fine, and better than his own bike. I tried kicking over his B31; it has the same gearbox. He was right. So it's not a problem at all! Doh!
The mystery is, why wasn't it doing it when I first got the bike? Oh well. I now know more about the bike, and the gearbox oil has been changed, though it wasn't too bad before.