'54 Plunger, 6 bolt clutch.

Please excuse the long post but I'm tearing my hair out here.

I've re-assembled my clutch and it's constantly in gear, despite the plates moving out.

Here's the back story.
All was fine with the clutch for the last year of owning this bike but last Monday, the clutch inner basket came off the shaft whilst out for a ride.

Got it home and removed the primary chain cover to fine the floating basket.

See image #1 for how it was assembled.
It had a "domed" washer fitted UNDER the basket, then the basket and finally the large conical nut that has the flat (presumably for a tab washer to lock it tightly?) Except mine had nothing locking the nut on, hence why it fell off.

Re-assembled it all today, putting the basket on first, then the "domed" washer and finally the conical big nut.
I tightened the out with an impact gun, not having a torque wrench and tabbed the washer over the flat of the conical nut, fitted the plates and started the bike in neutral.
Pulled the clutch, put it in 1st and it lurched forwards and stalled.
I found that the clutch, although the plates are moving out, is not affecting the gearbox.

Primary chain off, plates out of the clutch and I found that the inner basket does not move independently of the outer basket.

I've assembled it in order of the images below. (#2 #3 #4 & #5) but it would appear that it needs a washer / spacer UNDER the basket for the clutch to operate.

This is contrary to the parts diagram and there would be no space left on the shaft splines to fit the tab washer if a washer were to be placed under the inner basket.

Can anyone please tell me where I'm going wrong or what the problem is ?

I've got to get the bike running before the weekend.

Many thanks

My bike has a ball bearing that sits in the clutch adjuster (part #31) and is pressed on to the push rod by part #30 when the clutch is activated.

The parts diagram attached doesn't show this ball bearing

Should I have a bearing or not?
That's my question (having mushroomed two push rods)

Thanks

Part Number 65-3940
1/4" dia rod x 11 7/8" long

My new rod has failed
After only 25 miles, it has mushroomed to the shape of the ball bearing on the gearbox side adjuster.

Guessing it wasn't hardened correctly?

The supplier is unable to source another.

Can anyone advise where I can buy a replacement please?

Hi. Today, whilst riding, my clutch basket came off.
It appears that there's a large nut with a flange with a flat (that holds the clutch basket on the shaft) that had come undone.

I'm sure the flat must be for locking but can't see anything to lock it with.

Are there any exploded diagrams of the 6 spring clutch assembly anywhere please?

When I removed the right hand side case to replace my clutch push rod, oil came out.

When I'm putting it all back together, do I need to add oil or will it get oil from the sump?

If I do need to add some, how much please?

Many thanks

Hi.
Having just discovered why my clutch needs continually adjusting (end of push rod splayed) I'm struggling to find a replacement online.

Can anyone please tell me the correct length that it should be?
(I fear I'll have to buy a "cut it down yourself" rod)

And / or an original part number?

My old one measures approximately 11 3/4" but that's not accurate because of the splaying.
I'm guessing someone has fitted a non-hardened rod previously?

Many thanks

Many thanks

Has anyone fitted a side stand to a '54 Plunger B31?

If so, do you have any pictures (close up) showing where you attached it and where you got it from please?

Really struggling to get it on the centre stand every time.

Thanks

Hi.
Need some advice please.
My B31 plunger keeps bottoming the rear suspension on relatively small bumps when I'm two-up.

Is this "normal" behaviour?
Is there a way to stiffen up the suspension?
Are the plunger units relatively easy to strip and re-build (and if so, how?)

Incidentally, the front forks are really soft too - can they be serviced to make them stiffer?

Thanks

Just about to put my clutch back together after inspecting for wear and undecided if I should clean up the plates with brake cleaner?

The metal plates and friction plates were / are contaminated with oil.

Should they be coated with oil or should the clutch run dry? (Meaning I've got a leak issue somewhere)

Thanks

My biting point on my clutch is a long way from the bars and sometimes slips after changing gear quickly.

Adjusting the adjuster on the cable by the hear box only adds more free-play to the lever.

Ate removed the clutch plates and the friction plates have around 3.95mm (total thickness , including both wear surfaces and their barrier / backing plate)

Is the problem that there's not enough material left and I need new friction plates?
Or is there another way to adjust?

I'd like the biting point to be much closer to my bars.

I've found that the "points cap retaining spring" (don't know it's real name) is too short on my '54 Plunger B31 (see attached photo)

I need one that's 5cm - measured from the locating dimple to she centre of the mounting bolt.

Tried spares Stockists who say "they're just throw-away bits" and don't have one.

Having just fitted electronic ignition, which has a wire protruding from the points cover, I need the points cover to rotate as I use the manual advance / retard lever.
My retaining spring won't allow the spinning because the positioning of the locating dimple doesn't match the points cap.

Does anyone have the correct length retaining arm that I could buy please?

Today, I fitted (my friend fitted)    the electronic ignition and gpmjatmp switch to my B31, as an option to a magneto rebuild.

I thought I'd share some photos of placement in case it helps anyone else considering doing the same.

Thanks

Since I bought my '54 B31 in October, I've been having random cutting out and not re-starting issues, often moaned about on here.

New to the old 4 strokes, I was at a loss and many people said it sounded like condenser or magneto failure.

I took advice and bought the Thorspark electronic ignition, as a cheaper option than a magneto refurbished.

Took the bike round to a friend who knows how to do "stuff" and if set about checking the timing and points to make reference marks before fitting the electronic ignition.

He found my points were at 6 thou (instead of 18 to 20) and he swore blind that the points was my running issue.

How true could this be? (Out of interest)

The bike would run for 40 miles some times but them other times, only half a mile, before cutting out and only re-starting after several huge prods on the starter and flames shooting out of the exhaust.
Sometimes it would then be OK but mostly it would only run for a few yards before stalling again.  Once started, it would also stall / die as soon as the clutch started to bite.

Long story short, we fitted the electronic ignition and have now got to road test her but curious as to what people think about the points.

I'll post photos of where it was fitted, in a separate thread, just to assist anyone wanting to do the same.

Thanks

Can anyone advise what size and thread pitch, the magneto puller tool needs to be, for a '54 B31 please?

I may already have one that fits, from my vintage moped collection.

Thanks

My '54 B31 has running faults (as you're all probably aware by now)

Many people have suggested that the problem is my condenser failing.
The turn-around to get the magneto overhauled is around 6 weeks (and by then it'll be winter again)

I've found the "Easy-cap" (by Bright Spark) and Thorspark - both claim to be work-arounds for failing magnetosphere / condensers.

Has anyone out there, had any experience of using either product and any recommendations or/advice would be welcome.

They both seem to offer a quicker & cheaper solution to my issues, leaving ne'er to have the magdyno over hauled I'm winter.

Many thanks

I've spent the weekend on my first long rides on my '54 B31 and because I was with other bikeists, I've been able to get more of an idea what is happening and when . . . .

BUT

No one knows just what is causing the problems.

Here's what the bike does and the things I've done to try to fix the problem in past weeks.

Can anyone advise what it could be please?
(I think it's getting too much fuel when it's hot)

Randomly, the bike will splutter and cough, sending a cloud of black smoke from the exhaust as it does this.
Sometimes it will run for 20 miles plus, perfectly but other times it will misbehave as soon as it's warm.

Once it's started the cutting out, it won't re-start easily. I've since worked out that I need to pull the decompression lever in and kick the starter furiously (which results in one massive explosion that shoots flames from the exhaust and then a couple of further "very loud bangs" as I keep pumping the starter.
Once the bangs finish, drop the decompression lever and keep kicking furiously and she will fire up like there's never been a problem (sometimes - other times I need to repeat the explosions).
All the while, there's a strong smell of petrol (she doesn't need a tickle to start from cold and no choke - fired up first kick, just for reference)

Once re-started, I can literally only open the throttle a few mm on the grip before she starts the spluttering and stalling again.
I have to do long clutch-slips to pull away and as the revs pipe, change to 2nd before the over revving causes more spluttering.

If I only use the first few mm of throttle, I can eventually work my way up to 4th gear and if I increase the revs VERY slowly (in any gear) I can pick up speed, though only to about 30mph.

When she is moving along nicely, with minimum throttle, if I twist the grip on to give more speed / fuel, she starts the spluttering and will die UNLESS I throttle off a lot or change to a higher revving gear.

Trying to set off up a hill, even a gentle one, is almost impossible and I'm sure I've almost burned out my clutch.
When riding at a speed that the bike can tolerate, as soon as the extra torque for the hill kicks in, she starts to splutter and die.

I can replicate the condition when we've got going steadily on tiny throttle. If I wind-on it'd throttle, she will cough and splutter as above. Even when doing 45mph in 4th (eventually)  if I try to increase the throttle, she will splutter and stall if I don't recover it, by reducing torque and load on the engine.

I've fitted the following but all  in vain.
New plug, cap & HT lead. Cleaned points
Stripped the Carb and ultrasonic cleaned it thoroughly.
Cleaned armature & brushes.
Fuel cap breather hole is clear
Float definitely not sticking

Suggestions are: sticking valve, allowing too much fuel past and it's choking / flooding.

I'm at my wit's end with this now. It's so random when it does it and impossible to ride as it is.

Any ideas ed the solution are welcome.
(I'd even thought about borrowing  a Carb from someone, to discount that? (Any takers?)

My B31, I've just been told whilst on a run, that when it stutters, a puff of black smoke comes from the exhaust.

I've done 40 miles today without issue and then suddenly it all started again

When it cuts out and won't re-start, there's a huge backfire in the exhaust and then it will start up.

My pals suggest the exhaust valve is sticking and fuel is dumping.

They also say I should be using lead additive with my Super Unleaded.

Does this all seem feasible?

Could it be the answer to my random running issues?

As the title really, how can I reset the trip meter on my speedometer please?
I can't find any buttons or the likes.
Thanks

My B31 is intermittently cutting out and doesn't like re-starting.
It's very random and sometimes it runs OK.

I'm now in search of someone who can test my magneto / dynamo and refurb it if needed.

I'm based in Sheffield so local would be great but anywhere recommended would be great.
Thanks

1954 B31 Plunger with stock Carb.

Randomly, the bike will stall (even whilst riding) and not restart.

I've narrowed the problem down to fuel starvation - as the engine starts to die, tickling the Carb brings it back to life.

Carb has just been totally stripped and cleaned and the only thing I can think of would be incorrect float height (although the issue is random and sometimes it will run OK for miles and other times just for 50 yards before dieing again.

Could anyone please tell me the correct fuel height in the float chamber and how to adjust the float height?

Many thanks