I bought a 1953 A10 a few months ago and its running well. It had quite loud tappet noise though and that was a bit of a worry. I took the rocker box covers off the other day to adjust the tappets and found they were perfectly set (cold) at 0.010. That means the noise I was hearing is probably not tappets.
I am not familiar with the A10 or BSAs at all really. I was wondering if anyone had any suggestions about what the sound could be. I am reasonably familiar with tappet noise having owned British bikes for 40 years and I have no idea what else makes that sort of sound.
Are there any other symptoms? There really are a lot of other things that can make noises that kind of sound like loose valve clearances. - A broken valve seat: mine had one because some nitwit had installed a "lead-free" conversion a.k.a. cast iron valve seats. - piston slap: pistons loose in their bores will sometimes tick regularly. This should get better as the motor warms up. - dynamo chain. The sprockets are notorious for wearing unevenly or a bent dynamo armature shaft ( caused by a previous broken chain) will cause the slapping chain to tick. - primary chain. The lousy tensioner on these bikes mean the chain usually slaps around a lot.
OTOH, they are just kind of rattly...
(Hoping to get my own golden flash back on the road soon)
A smattering: '53 Gold Flash '67 Royal Star '71 Rickman Metisse '40 Silver Star '37 Rudge Special sixtyseventy Lightboltrocket road racer...and many more.
The only thing I would do would be the measure the end float on the crank. As long as it is within spec by a couple of thou you shouldn't have any concern. If it has about 020" of end float then you might want to get it sorted.
Otherwise, I wouldn't worry too much and just ride the bike.
Also if you put a screw driver to your ear and place the buisness end at various areas on the bike - it will narrow down where the noise is coming from.
Is it worse on acceleration, over run, under load, higher rpm's or constant running?
My A10 used to have a tappet noise, turned out the carb slide was chattering in the carb body,Replacement body & slide soon sorted it.I would also check the tappet adjusters if the tappet lock nut is close to the square adjuster then the cam followers are likely to be worn as tappets are on full adjustment.
1941 BSA WM20 1958 TRI-BSA 750 PRE UNIT 1957 THUNDERBIRD 1932 R E MODEL GS SPECIAL 1947 BSA YM21
OK, thanks to you all for your advice. It looks like it was a loose dynamo chain. Never having owned anything this old before I didn't even know I had a dynamo chain until Alex mentioned it. Anyway, I have dealt to that and took the opportunity to maintain a whole lot of other things that were looking for trouble.
I checked out the slide too (thanks Tribsauk). Very pitted body and a badly worn slide so I will replace those too (although I can't get anything out of AMAL at the moment).