broken gearbox ?

Replaced the clutch an have got a lovely over centre action. wanting to check drag before starting up put it in gear but it just rolled as if in neutral. clutch not turning. kickstart also does not have any resistance. I don't rememeber anything going crack but did tighten the clutch centre nut to 70 lb foot using holding clutch lock tool.
please can someone let me know the bad news. I did remove the gear change transfer shaft but it seems to have gone back ok and I can hear/ feel the gear change.
thanks for the advice

davidcumbria said:

I don't rememeber anything going crack but did tighten the clutch centre nut to 70 lb foot using holding clutch lock tool.

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The book figure of 70 ft./lb. is too much (and probably an error carried over from the Atlas/Dominator manual)
70 ft./lb. could have sheared the circlip behind the clutch which is maybe why there's no drive. 40 ft lb. with Loctite is enough.

Amen to another misleading nay damaging data point in factory manual. Clutch locator circlips are a consumable like tires and carb slides so get a few extra and realize not much force is trying to shove clutch off its shaft.

Although 70 ft lb is high and you may want to back it off, but I do not thing that is your issue. If the clip was sheared your clutch would not work and the action would be null. If you were to watch your diaphram, the entire clutch would move and the proper feel would be gone and unattainable.

Back the clutch adjusting screw out in the center of the diaphram. The action you describe is as if the clutch lever is pulled in and a broken clip will be as if it did nothing when pulling it in.

Something seems bound up in the clutch but could be in the gearbox.

One thing that prevented me from being able to adj clutch was eventually found to be the RH main shaft nut had backed off. This allowed the main shaft to shift instead of the clutch plates. Another time failure to engage was worn bushes plus cog dogs worn, I assume from the bushes tipping the cogs. And another time or 3 the lever ball where cable attaches fell out of its valley.

Yes, I also had on issue where the clutch release locking (#35) worked itself out. But again, this produced a different problem than what is described here.
http://www.oldbritts.com/1972_g7.html

hobot said:

One thing that prevented me from being able to adj clutch ...... And another time or 3 the lever ball where cable attaches fell out of its valley.

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Problem solved and thankfully nothing broken ! Ithink the above was the root of the problem which had led me into incorrectly setting up the adjuster. all fine now and with new plates and a tight centre nut which I discovered loose when i first pulled the clutch apart I finally have a bike that I can ride. Gear change and clutch are so sweet now.

also big sense of satisfaction in completing my first significant overhaul on the bike (or any bike after brealk of 30 years and two years riding new ones)

only lasting problem is engine stalling when coming to halt at junctions. A big part of this previously was clutch drag which has now gone - could it be that the carbs are out of synch ? engine also become a bit surgy on a small constant throttle ...

thanks again - This site is proving so useful to me

Congrats on sussing out the clutch problem. Surging at small constant throttle (especially 2nd gear down main street -- hell no, not Main Street America -- in traffic) to me means new needle jets and also I do new needles at the same time. Mine also would die at stops. I recently switched from Boyer Mk3 to Pazon Altair and that fixed that wonderfully but there are many who run Boyers and it doesn't do that. Check carb synchronization and make it perfect - See Bushman site listed in the Technical notes at the beginning of this forum.

Alrighty David makes all our days to hear of successful fettering. Besides Dogt's advise must have enough volts to run Boyer brain so maybe just dropping below 10ish v when at idle.

I concur, it is probably the clutch locating circlip that has broken.

Naw those locating circlips don't break so much as they just get reversed umbrella'd laid back jammed over shaft. I guessimate this happens about the 40ish ft lb torque level. Will have to T-wrench measure this to know for sure rather than by guess and by golly. I keep a few circlips on hand as consumables, same as tire patches so I can spare another to know how little torque we can get away with safely.