What have you done with your bike/s today?

[chaterlea25]

Hi Worty,
Recently I was sorting a BSA single 6 spring clutch,
Rather than try and true the pressure plate
(Coz you can't), i set up a dial gauge and measured the lift adjacent to each spring,
A bit of fiddling and I had very near equal lift at  each spring!  It worked for me

As the spring pressure increases the lift decreases due to the pressure plate flexing so its possible to over do the spring pressure easily

John

[Worty]

Thanks John, your method seems a lot more 'doable' than trying to true the pressure plate.

I may need a new set of plates as I'd tightened the nuts slightly to eliminate a bit of slip. 

Would I be right in saying that the nuts should be tightened only to the point where the clutch doesn't slip under load.  I did put on new nuts and springs some years ago.

It's always seemed a bit weird that although the springs are equal length, the nuts don't screw on equally.  With the Kwaka, for example, you just put on the plates and tighten the bolts until they stop - easy.

I'm using the Kwaka oil in the primary, which seems fine, and it's not overfilled.

[chaterlea25]

Hi Worty,
Correct, plus maybe a half turn to allow for future wear.
They are very haphazard compared to modern Japanese clutches.

I have a plan to modify a Suzuki clutch to replace the 6 spring unit, i'm waiting to hear back from a guy who has access to lazer metal cutting to cut a spline to fit onto the BSA shaft adaptor.

John

[Swarfcut]

 Reckon Worth's clutch is dragging, so trouble finding neutral. Clutch cable starting to slacken means less lift on the clutch so it will not free completely.

 One reason for cable stretch is that the nipples are moving,another is that the cable about to break, from experience a seized handlebar lever nipple will fatigue the cable..... Next thing, twang ----- No Clutch.
 
   A spare clutch cable in the toolbox is worth a punt. Close examination of the existing cable may save a primary side stripown. There must always be a small amount of free play on the cable with the clutch fully engaged.

 Swarfy.

[Worty]

Reckon Worth's clutch is dragging, so trouble finding neutral. Clutch cable starting to slacken means less lift on the clutch so it will not free completely.

 One reason for cable stretch is that the nipples are moving or the cable about to break, from experience a seized handlebar lever nipple will fatigue the cable..... Next thing----- No Clutch.
 
   A spare clutch cable in the toolbox is worth a punt. Close examination of the existing cable may save a primary side stripown. There must always be a small amount of free play on the cable with the clutch fully engaged.

 Swarfy.

Cheers Swarfy

The cable is new to accommodate the higher bars.  Nipples are soldered solidly and the lever end is sound.  There is about 3mm free play in the lever with the clutch fully engaged.

I do carry a spare clutch cable in the toolbox, along with a screw on (get me home) nipple arrangement.

I think the plates are wearing, which may be the reason I've had to screw the nuts down a bit more to eliminate clutch slip.  This would mean less lift on the pressure plate and possible clutch drag.  Cue a lot of heat and metal expansion, and I have a problem.  When at normal temps, the clutch isn't bad, although a clunk into first can sometimes be apparent.

Overall, my bike does NOT like to be very, very hot.  As well as the clutch, it can spit at me and occasionally stall (rarely, in fact).  It did spit and cut out round Bradford, but ran fine once I had a chance to get her on the open road.

[RDfella]

Getting there slowly with the B31 / M33 engine.
As previously noted, bit of a disaster on the hill-climb start line - exhaust cam follower broke and the foot smashed the crank pinion and exhaust cam. Have straightened the crankshaft, made a new key & fitted a spare pinion I had. Found the exhaust cam spindle was bent .002" so dressed that with a diamond file. Got a new 2446 cam and checked the valve timing with a disc. Not easy, given those cams have quieting ramps. Was close enough though and,as John said, those new cams are incorrectly marked for timing - a tooth out in fact. Also, whilst the cam looks very well made, the lift is .025" short of what it should be. Also, when bolting up the outrigger plate, the engine locked up. The new cam was a fraction too long, so ground .010" off the front face and all was well. Wish I could have sourced a 65-2491 cam, but they were rare in their day, and now impossible to find.

Next issue was the exhaust valve. The collets had started settling into the spring retainer - again. In fact, I narrowly avoided a disaster last time, as the cotters had split the retainer. So this time I looked for a longer valve stem so I could cut a slot for KK9 cotters (they're 14 deg instead of BSA's 10 deg or 8 deg on early ones) and then shorten the stem to suit. Happens the only suitable part was an exhaust valve for an 80's 911 Porsche. The Porsche spring retainer required smaller dia springs and, not knowing their length, decided to use the BSA springs instead, and followed Musky's method by boring the BSA retainer to 14 deg. to accept the new collets. Was surprised how soft those retainers are. Just waiting now for some Meehanite to make a new exhaust guide to suit the valve.
Here's hoping it runs OK when completed.

Been nearly a week's work so far - and then there's property maintenance to be done (it's getting a struggle now, but employing tradesmen would cost a fortune). Painting alone (don't get me started on modern paint - the best only lasts 3 yrs, whereas the old lead paint was good for 10) is like the Forth bridge. Got 5 x dormers, 13 x windows, 2 x French 'doors' and 10 x doors to do - and the two workshop ones are 12ft x 12ft. Sanding, priming, undercoat, gloss .... I go around them in a 3 yr cycle, but those French 'doors' are a nightmare.

[BagONails]

Reckon Worth's clutch is dragging, so trouble finding neutral. Clutch cable starting to slacken means less lift on the clutch so it will not free completely.

 One reason for cable stretch is that the nipples are moving or the cable about to break, from experience a seized handlebar lever nipple will fatigue the cable..... Next thing----- No Clutch.
 
   A spare clutch cable in the toolbox is worth a punt. Close examination of the existing cable may save a primary side stripown. There must always be a small amount of free play on the cable with the clutch fully engaged.

 Swarfy.

Cheers Swarfy

The cable is new to accommodate the higher bars.  Nipples are soldered solidly and the lever end is sound.  There is about 3mm free play in the lever with the clutch fully engaged.

I do carry a spare clutch cable in the toolbox, along with a screw on (get me home) nipple arrangement.

I think the plates are wearing, which may be the reason I've had to screw the nuts down a bit more to eliminate clutch slip.  This would mean less lift on the pressure plate and possible clutch drag.  Cue a lot of heat and metal expansion, and I have a problem.  When at normal temps, the clutch isn't bad, although a clunk into first can sometimes be apparent.

Overall, my bike does NOT like to be very, very hot.  As well as the clutch, it can spit at me and occasionally stall (rarely, in fact).  It did spit and cut out round Bradford, but ran fine once I had a chance to get her on the open road.

Worty, a couple of years ago my clutch was slipping so I fitted new SRM clutch plates, as a set, along with their machined alloy pressure plate which has a proper thrust bearing. Everything else in there is standard 4 spring Triumph type clutch.  It now works faultlessly after some careful set up, I haven't had to touch it. Money well spent in my view. I did replace the springs, nuts and other components but only because everything was knackered or wrong! These clutches actually work very well when correct and in good condition. Now I can always select neutral at a standstill, in fact sometimes I have to feed in a bit of clutch to engage 1st because there is absolutely no drag!!