Kickstart Jammed?

[Swarfcut]

 For those folks with a kicker that jams up, a trick is to put the bike in gear and push it backwards. This will turn the gearbox mainshaft backwards and throw the quadrant out of engagement with the ratchet pinion. A further push  forward in gear will bring different pinion teeth ready to accept the quadrant, and with a bit of luck the kicker will work. This pushing can be done with the clutch pulled in, we're not moving the primary chain.

 They jam because of general wear or damage to the parts, the pinion especially. Also mis-matched tooth profile for the pinion and quadrant, all this is on the Forum, just a matter of a bit of research.

 When the cover comes off for inspection, chances are you'll be amazed it worked at all!

 Swarfy.

 

 

[Big_Ben]

Thanks Swarfy

Gearboxes... the dark arts!

So, I emerged from my Rona pit and tried this, results posted here in case it sheds light on my problem?

Rolling the bike backwards with her in gear, the kick start lever rotated counter clockwise (so as if being kicked).

Then rolling the bike forwards it rotated clockwise (as if returning), and the kicker/gearbox still seems to be locked up.

I'll fiddle with her some more when I can think straight.

[muskrat]

G'day Poppy.
That description sounds very strange. It sounds like the kicker is jammed mid stroke. Is this the case?
If so, pushing the bike forward the kicker would move in the normal kick direction counter clockwise. Pushing the bike backwards should move the kicker clockwise and eventually release.
Most of the time if a kicker jams it's at the top of the stroke and a simple rock backwards in gear clears it.
Possibly you have miss matched quadrant/pinion and/or a badly worn pinion bush.
Cheers

[Big_Ben]

@Swarfcut and @Muskrat

My bad. Memo to self, don't try to be intelligent when sick.

I went had another look at it, and you're absolutely right and I'd said it the wrong way round.

Not only that, but I juggled the bike and the furniture and pushed it enough for the kick start to travel to the end of it's travel.

Bingo, lift up the kick start and she's no longer locked up.

Hard to be sure, but I think that the kick start return spring was working, but it definitely is not now.

Still, progress is progress. Many thanks Poppy

[Swarfcut]

 Poppy.. Good news....thought I was losing it. So now the kicker moves, you reckon the spring has failed?

 There are two types of spring. The early type which is flat, like a clock spring, secured with a peg at the fixed end, shaft end hangs onto the quadrant splines by its fingernails. Set up too loosely it will bear on the ratchet pinion and click as the bike is pushed. Later type is a conventional wire wound sort, hooks over the quadrant, fixed end  is a bolt and external locking nut. This spring is far easier to tension correctly.

 If the gearbox cover has a grease nipple on the clutch arm and a curious looking nut adjacent to the kicker shaft, its the later type. These features are absent from the early cover.

 Your pictures show a grease nipple, so on the face of it the gearbox cover is the later type, and my guess is the gearbox is not contemporary with the motor.

 What's inside is anyone's guess.

 Swarfy.

[Big_Ben]

Your pictures show a grease nipple, so on the face of it the gearbox cover is the later type, and my guess is the gearbox is not contemporary with the motor.

Hi Swarfy et all.

OK, took some more photos. Looking forward to getting the cover off but not 'till I'm better.

The motor is contemporary to the plunger frame, and the gear box is a bolt on type (or at least I think that is what I'm seeing).

Does that mean that the older and newer gearbox outer covers can be exchanged, or is it that "later" plunger boxes had the grease nipple etc?

BSA do seem to have changed an awful lot of things as they went along. I'm sure there were good reasons...

Thanks again, Poppy

[Swarfcut]

 The good news is that the dimensions of the castings,(shell, inner cover, outer cover) stayed the same.  Any plunger box will fit any plunger motor.

 BSA were never radical when it came to change, they implemented relatively minor tweaks over time, fettling and improving the original basic design. The extravagant lifestyle antics of the top management had a lot to answer for.

 The later plunger box cover, as yours appears to be, has the grease nipple and the kickstart spring will be the wire wound type, see the locking nut for the spring retaining bolt next to the kicker shaft, at the back.

 The cover is certainly later than your Longstroke motor. But as the covers interchange, the rest of the box could be from the time of the motor.... or a complete later box entirely.

 Swarfy.

[Big_Ben]

Thank you, much appreciated.

[chaterlea25]

Hi Poppy
I just noticed that the kickstart cotter is fitted from the front,
This puts the lever way back at an angle, It should be fitted from the back which will position the kick lever more upright

John

[Big_Ben]

Cool, thank you for pointing that out.

[Minto]

Just noticed this thread and thought I could add summat.
My kickstart locks up regularly but I find that as long as when it’s returning I stop it just short of fully returned it stays free, the last couple of inches can be eased up under control. Not jammed since I discovered this.

[Rex]

Good idea. It's keeping everything in mesh rather than forcing it to re-engage again.