Author Topic: jumping chain  (Read 1513 times)

Offline derek taylor

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Re: jumping chain
« Reply #15 on: 06.05. 2014 06:33 »
just been thinking could the lugs on the new clutch plates be digging into the basket (them being sharp)

Offline muskrat

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Re: jumping chain
« Reply #16 on: 06.05. 2014 21:12 »
G'day Derek.
Have you ridden the bike since? Have you tried to replicate the situation?
I think I'd be stripping the primary down again. Check for Wilko's suggestion of main shaft key.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline derek taylor

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Re: jumping chain
« Reply #17 on: 07.05. 2014 18:53 »
been on the bike its done it again just jumps when letting clutch out in 1st gear otherwise its ok.
carn't grasp the thing about the key way if its slipping the key must be sheared if that's so it would slip all the time.

Offline bsa-bill

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Re: jumping chain
« Reply #18 on: 07.05. 2014 19:40 »
My thinking - if it's just first gear it's maybe due to first providing more torque then any other gear which might point to the key theory or it's down to first gear itself like in the box somewhere
All the best - Bill
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Offline muskrat

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Re: jumping chain
« Reply #19 on: 07.05. 2014 21:05 »
That could also point a worn/chipped dog or bent selector fork.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
Muskys Plunger A7

Offline Rocket Racer

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Re: jumping chain
« Reply #20 on: 08.05. 2014 22:17 »
I'd concur with Muskrat and from the picture it appears your sprocket on the clutch basket also look fairly worn, which if poorly aligned could be hooking up when you pull in the clutch.
Tie the clutch lever to the bars so the clutch is disengaged and look at how it rotates/aligns, chain alignment is important.
But your front sprocket tooth profiles look far more healthy than the clutch sprocket teeth do.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand

Offline derek taylor

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Re: jumping chain
« Reply #21 on: 27.05. 2014 06:40 »
right then not stripped anything down yet but took it for a run yesterday, its the clutch you can feel it slipping and biting through the leaver as you let it out.
two things tho it only seems to do it when the engine is hot have also noticed some slack has appeared in the cable at the leaver. also if you pull up at a junction in first gear and pull the clutch in its wanting to creep forward.

Offline Rocket Racer

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Re: jumping chain
« Reply #22 on: 27.05. 2014 20:54 »
keep in mind you can always remove the primary cover and run it with everything visible.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
New Zealand