Gear selection whilst bike is static

[Captain Mike]

Hi
I am in the process of getting my bike back on the road , and in the process of setting the ignition timing, during this I have not been able to select the gears to get it into top gear to enable me to turn the back wheel to rotate the engine, I have the gearbox casing off at the moment for polishing so I can not operate the clutch, however no matter how much I move the gear lever I can not seem to get the gearbox into Neutral or any gear, is this normal or am I doing something wrong, the gear selector seems to be moving ok , not very experience with gearbox's so any guidance would be appreciate

Thanks
Mike   

[DAVE BRADY]

Hi Mike,

Are you turning the wheel a bit as you try to select a gear?  Bear in mind that the gear box is usually turning when selecting a gear.  This make it a lot easier for the selectors to move the gears.

Dave.

[Gadorey]

You don't need to operate the clutch to change gears, if the engine is not running.
Try rotating the back wheel by hand while operating the gear lever. It should then click into place. If not, then you have other problems.

[Captain Mike]

HI thanks for the feedback, looks like I have other problems !

I have been trying to turn the wheel wheel whilst operating the gear lever as you suggest, but to no avail, when I bought the bike I wheeled it into the garage in neutral and put it on its stand with no problem, seems I have put it into a gear whilst trying to find top gear to spin the engine for ignition timing and cannot get it out now, the selector seems to move up and down with no problem, but I cannot tell what is happening inside the box

The bike has been completely rebuilt before I bought it , I'm thinking is something simple that I am missing

Thoughts/ suggestion ?

Cheers
Mike 

[Pete A10]

I had a simililar problem when I rebuilt my A10. I couldn't sort it with everything in place and ended up removing the gearbox and rebuilding it again. I think I found the problem in that I had indexed the quadrant one tooth out of position. Re assembled carefully and everything now works well. That had similar symtons as it seemed alright until I put it in gear to turn the engine to do the mag timing - then the change mechanism just jammed up even though the shafts were turning.

[DAVE BRADY]

Hi Captain Mike,

Is it an A10 or an A65?  A65 does not need indexing but if it is an A10 then as Pete says it needs to be indexed.  There are dots to help with this.

Dave.

[Captain Mike]

Hi

Dave/Pete

Yes it is a A10 pluger, looks like I will have pull the gearbox apart, this will be a learning curve for me, so I will research it first, is there a way to do it without removing the box from the bike ? has anybody else done this ?

will update progress when I get the time to do the job

Thanks

Mike

[DAVE BRADY]

Hi Mike,

You do not have to remove the box from the bike but there is bit of stripping to do.  I had to do this on my wife's '51 Flash and from memory the outer and inner gearbox cases have to removed.  I think that the box needs to be in second gear and then as the inner cover is put on the dots must line up on the selector.  It is easy to let it drop at the last minute and this could what has happened.  New gaskets will probably be needed.

Dave.

[Captain Mike]

Looks to me like the gear change lever is not moving the gear cam plate after having a closer look

[Captain Mike]

Thanks Dave

At this point in time I have no Idea what gear the gearbox is in, However I will remove the inner casing to see if I can understand what is going on

Thanks for the help
Mike

[Pete A10]

My A10 was a swing arm model with the totally separate gearbox. I don't know if your plunger has this box or the semi-unit item where the box is bolted to the engine. If it's the latter then I can't really offer any advice. If it is the separate box then I found it easier to take it off the bike as I couldn't manipulate anything in the gear box even with inner cover removed. You have to remove the primary drive, the clutch and the casings to get at the grub screw which holds the selector shaft in the gearbox. By the time you've done all that it easier to to drop the rear right engine plates off and take the box out. You can then put the gear box on the bench to rebuild it. A lot of work I'm afraid but it was the only way I could do mine.

[Captain Mike]

Hi Again
After doing some research I have found out that my 57 Flash Plunger has the semi pre unit box bolted to the engine, so I am not enthusiastic about pulling the engine out to get the box out

As for the problem ; I can move the gear selector arm by hand up and down without the cam plate moving inside the box, this leads me  to believe either something has dropped off or the gear selector arm plunger has not been set correctly, I want to remove the gearbox inner cover to assess what has happened if I can, my question is, what is the procedure for removing the gearbox inner cover with the box it still in the bike, I have tried pulling it off but not sure if I need to remove the kick start ratchet pinion and other parts, any advice will be appreciated

Cheers
Mike   

[DAVE BRADY]

Hi,

You will need to remove the kick start ratchet mechanism as it is attached to the main shaft which has the clutch on the other end. Once this is off the inner cover should come off.  As it is on long studs it may take a bit of wriggling. It does sound like it was not indexed on assembly. 

Dave.

[Pete A10]

BSA service sheet 209 available in the members section details the procedure for stripping the gear box on a rigid/plunger A10 without removing the engine and gearbox from the frame. Interestingly it doesn't mention indexing - it must be significantly different from the separate gearbox mechanism. The symtons you describe, however, are exactly what I had when my box was wrongly indexed so it must be something in the way the change mechanism that is not quite right. Possibly the claw not fully engaged with the quadrant ratchet. Happy hunting.

[Captain Mike]

Thanks Dave and Pete

I will report any findings, I thought I read that there was no indexing dots on the Plunger framed Gearbox's ?

Mike