Burman 52 gearbox - clutch issue

[G3L1946]

Hi Groily and G80csp11,

The cable was checked up against the one I took off ( hopefully that was correct in dimension ) and was found to be the same. I then measured inner cable exposure which was the same as was the adjuster length. I made reference to the ‘55 parts manual and confirmed measurements. The inner and outer cable lengths are the same as the original ( I removed as the inner appeared creased and fractured). Happy with cable. DEFINITELY the correct length rod and new from club. One ball on correct end of correct dimension. It is a new lever but checked against original and found to be dimensionally the same ( new lever as original had its end broken). Can’t even get a clunk now, just horrible graunch and won’t select.
Groily, I took support off as I’ve been adjusting the lever as part of my experimentation to sort the clutch problem out. I have noted the gap between handlebar and clamp which creates additional stress and also have a support under the brake lever also. I think I read a thread of yours some time ago mentioning this which prompted my action towards this.

As I sit here I’m still no further forward so will just try to think logically where the issue lies. At the moment, failing!

Regards,

Steve

[Ralph]

Have you got the right number and size of rollers in the clutch hub?

[G3L1946]

Hi Ralph,

When I stripped it down all seemed correct. The right number for sure and appeared correct size and fitted correctly.
I’ve now replaced the new cable with the original. It’s not a lot of good as it is frayed but will serve for testing purposes. Still looks the same length but, as it’s all bent and in poor order, it’s a bit hard to confirm. The testing goes on.

Thanks,

Steve

[clive]

Hi all,

Yes, sorry Clive, I was a bit misleading there ( not intentionally ). In an early post I mentioned that I eventually got the gears to select with the ‘clunk’. When I returned from a very short first ride I noticed several issues that needed addressing. One was an oil leak from the kickstart cover which I took apart, cleaned and refitted with a new gasket. Since then I’ve not been able to get the clutch set up correctly. This all took place over a short period of time, about 5 days and although I was able to select gears on the way out by the time I got home the problem became apparent. I’m starting to get the impression that the plates are not parting completely maybe due to uneven separation or snagging. As I said, the basket was free of any burrs or other problems. I did mention that when I originally took the clutch apart there was a ball at each end of the actuator rod. I replaced the old rod with a new correct one and replaced with just the one ball as in the manual. Just for bit of an experiment replacing the ball ( one each end) make no difference whatsoever. Incidentally, the old rod was also the correct length for this gearbox/clutch.
Steve

Now we may be getting somewhere. The clutch worked ok until you took the kickstart cover on the gearbox off due to an oil leak. My money is on the fact that whilst replacing the cover the relationship between the gear change quadrant G-25-2 and the cam 018337 has been lost. This would mean the quadrant was not able to properly rotate the spindle and hence no gear selection. Trouble is its a while since I have had the B52 box apart and cannot remember how you ensure they are properly aligned. It must be in some of the articles on the gearbox though.

[SPRIDDLER]

Now we may be getting somewhere. The clutch worked ok until you took the kickstart cover on the gearbox off due to an oil leak. My money is on the fact that whilst replacing the cover the relationship between the gear change quadrant G-25-2 and the cam 018337 has been lost.

Exactly that has also been in my mind today as we seem to have eliminated all potential clutch issues. We've covered everything from pushrod length to h/bar lever in the preceding 4 pages. Since the fault still existed even when using the old plates the only thing left is some misalignment when replacing the k/start seal.
There are several articles in the archives on B52 strip and reassembly which will cover the setting up of quadrant and cam which I'll leave Steve to trawl through, here.......

http://archives.jampot.dk/technical/Tra ... on/Burman/

[G3L1946]

Hi guys,

Thanks for your thoughts and links. As per my earlier post I did point out that on my return the problem became apparent. This was prior to me taking the kickstart cover off to replace the gasket.
I could well be that after I replaced everything I made things worse? So, I’ll take the advice , look at the link , and take a look to see if I misaligned anything. My only observation would be that if misaligned would the gears still select when engine not running? I’m able to select all 4 gears whilst engine is not running.
Thanks for taking time to help me out,
Much appreciated,

Steve

[G3L1946]

Good morning,

Replaced old clutch cable, same result. However , two things emerged. My initial assertion that both cables were identical has proven incorrect. It would appear the new cable is slightly (1/4”) longer in length of its outer. The inner appears slightly longer too. Secondly, I’m now pretty sure the correct analysis is misalignment ( the gear pedal is not selecting all four gears correctly as I thought ) which I will inspect and rectify. I intend to shorten the new inner cable and replaced the nipple to bring it to the same length as the old one. Can the type of nipple ( see photo ) be obtained? I’ve had a look online but can only find the screw on type which would not fit.
I think I might be seeing light at the end but I feel a bit of a twit that I was so confident the cables were Identical. It became obvious when the old adjuster wound much further in than the new one and I then put the two cables under slight tension and laying parallel with each other.

Regards,

Steve

[Groily]

A lot of folk go here for bits and pieces for cable making:
https://www.venhill.co.uk/cables-and-co ... nents.html
The hard bit is getting the cable squeaky clean really. There are threads on here showing folks' preferred methods - eg viewtopic.php?t=22416
Personally, I don't find it all that easy to do a decent job on the heavy-duty items, ie clutch and brake. So I tend to cheat and use an additional ferrule with a split in it to extend an outer cable, thereby avoiding having to cut off a perfectly good nipple and solder another one on the shortened inner.
Horses for courses and 'needs must'.

As for getting the register right on the barrel cam, there are different views on what's easiest. I usually manipulate the 'box into neutral and then make sure the detent plunger locates in the 'neutral' indent on the rear of the barrel. Others may prefer to set it up in, say, top gear - but as long as the plunger is in the correct indent for whatever gear it's in (and the pins in the selector arms are in the tracks of course!) it should be OK. That said, loads of people have fouled up on this now and again, I know I did in the dim and distant.

Hope all now goes smoothly.

[G3L1946]

Hi Groily,
All taken on board, and thanks for tips. I have the old adjuster ferrule so I think I might take that route too.

Thanks for your help and time taken. I appreciate it very much.

TTFN Steve

[SPRIDDLER]

It would appear the new cable is slightly (1/4”) longer in length of its outer. The inner appears slightly longer too.

I wouldn't start modifying the cable yet.
If the inner and the outer of the new cable are both longer than the old one........


Lay both cables alongside each other. Pull the gearbox ends of the inners through so that the nipples at the h/bar end are against the outers.
Measure the length of both exposed inners. If the amount of exposed inner is greater on the new cable than on the old one just fit something as a spacer over the inner to reduce the amount of exposed inner. E.g. a split ferrule or a nut with a slot cut in it. Squeeze the ferrule, cut nut etc. around the inner so that it doesn't grip the the inner and cannot drop off.

G adjuster 2.jpg