Questions about A50

[AdrianS]

Hi,
I am new to the twin section having only BSA singles in the past.
I have acquired an early A50 which has had a lot of work done to it and starts and runs well.
Like every new toy, I have to put my own mark on it and also check it over and "mess" with it!
A few questions ( and I'm sure there will be many more):

1. Is there an online workshop manual available? I find the Haynes manuals not very good and are very non specific - I have the Haynes manual.

2. The front forks are noisy with what sounds like spring noise when compressed. I want to change the oil and possibly look at the springs. On the drawings they appear quite short. Any advice appreciated. I must admit when riding I cannot hear the noise , it is only when pressing down the front end when stationary.

3. There appears to be a Whirring noise from the primary drive. This may be completely normal but was wondering if I should remove the cover and check the chain tensioner and have a look around inside?

Cheers for any help!

[JulianS]

There is a workshop manual in the members area on the BSAOC website.

[AdrianS]

Manual now sorted

[DAVE BRADY]

Hi Adrian,

The A50 and A65 are pretty much the same and share the same rattles and noises.  This is exacerbated by the 'echo chamber' that exists under under the cases around the gearbox.
However,  I would check everything anyway and especially the primary chain.  It is only meant to have 1/8" play so is easy to get a bit tight or even a bit slack.  It may be worth checking the clutch bearings and thrust washer whilst at it.
Noisy fork springs seem to be a common issue on many BSAs. A bit of grease may help but unless the forks are dust proof it can attract dust and grit and cause wear. Spring noise can also come from the rear suspension as well.
You will also hear quite a bit of noise from the tappets and valve gear even when in best condition.
I wear earplugs when riding which tend to cut down on the higher frequencies and wind noise leaving the 'proper' engine noise to enjoy.  Also, I find it easier to identify unusual noises when using ear plugs.   

Dave.

[AdrianS]

Cheers Dave

Will check the primary chain play - I believe it can be done by opening the filler cap.
Out of interest, is the tensioner blade prone to wearing much? How often does this need replacing?
I assume the clutch bearings and thrust washer can just be checked by feeling the play by hand on the clutch assembly.
WRT the fork springs, what is the best way to access them? I will change the oil in the forks as a matter of course. I cannot feel any play in the fork bushes.
One other question, I want to change the steering lock - what's the best way to access that?
Cheers
Adrian

[DAVE BRADY]

Hi,

Yes, the primary chain can be checked through the filler and if the clutch is particularly wobbly you may be able to feel this especially if the chain is a bit loose.  The tensioner blade has a thick pad on it which in theory can wear through but on my high mileage A65 I have not replaced it.  The plates of the chain will wear grooves until the rollers make contact with the pad and then wear seems to almost stop!
To get to the springs the fork legs need to be dropped out of the yolks.  There is a special tool for pulling then back up in to place which makes the job a lot easier.  One can be made using an old fork top nut with the hex. filed off and some stud bar attached to make a puller.  If you are going to remove them do this after draining the oil and before refilling as the oil may escape vertically as the stanchion drops into the slider
The manual should cover the steering lock replacement. There is a grub screw that holds it place and new locks are available.

Dave.

[berniej]

Hi Adrian - one source of a knock that you hear when rocking the bike with the front brake on to compress the forks could be slack between the slot in the brake backplate and the lug in the inside of the fork leg. Quite common and easily cured with a U shaped piece of alloy or other suitable shim material.

Cheers,
Bernie

[AdrianS]

Found that knock Bernie!

Already thinking about what to pack the gap with!

[ChrisG]

Adrian,
A whirring noise in the primary chaincase can be the chain tension slipper as Dave described. If its a new tensioner, this noise can be apparent until it beds in. Check the chain adjustment first, yes the upper hole in the cover is the one. However, because the chain is so far back it may feel tight when checking with your finger. I use a small screwdriver and get some leverage on it. Keep an eye on the chaincase oil as well.
Re the front forks as below, I made an upside down L shape shim using shim steel. It took me about two minutes -job done!