Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board First BSA, 1972 A65L, Engine troubles

Hi, my name is zoltan and I just picked up my first BSA, british bikes were what got me into motorcycles but could never afford anything but a japanese bike until recently. I have been working on japanese bikes for a while now, but this is my first british bike. I acquired this bike in Connecticut from a big british bike fan who told me the bike runs and rides but theres a clanking noise inside the engine and hasn't dealt with it or care too. I got the bike started, however its not idling, though I have yet to clean the carbs and do some basic maintenance on it. What is more concerning to me is the engine clanking, which increases with revving. I am not against pulling and opening the engine. This is going to be a fun winter project for me. The sound, sounds like it is on the top but maybe you guys can give me some further insight from the video below.

Any general tips regarding british bikes or common issues with this model would be greatly appreciated, thanks!

Could be something simple, check the valve clearances, taking the valve cover off and looking for something loose is also quick and easy. On the idle get hold of a #78 drill, mount it in a wd40 plastic tube using glue, remove the pilot mixture screw and then finger twist the drill through the pilot jet to remove the crud.

Does sound top endy.

Welcome, Zoltan, and congratulations, the bike looks very nice. I bought my first BSA, a 1971 A65L, three years ago, and this forum has been a great help. The sounds coming out of my BSA are different than the sounds that come out of my Triumphs, I am still getting used to that.

First thing I did after getting the BSA was to buy a FACTORY shop manual, a genuine parts book, and an original owners handbook. You should be able to get them from some of the forum sponsors, or resort to eBay (I confess!).

Thanks for posting the pic and the vid, it really helps. Please post lots more pics, or link to an album, I for one will be glad to look them over. If I lived closer, I'd offer to have a look in person.

It sounds like it is running on one cylinder -- are both head pipes getting hot? If it is running on only one, the clank could be the sound of the piston in the dead cylinder slapping around. Since you have worked on other bikes I'm assuming that you know how to check for spark and check compression.

Before starting my bike the first time, I pulled the carbs off and apart for cleaning and to check all the components. Lots of help on this forum on what to look for if you do.

But "clanking" may be cause for alarm. Might just be time for that winter project you mentioned.

Please tell us what are the two letters after "A65L" in your frame and engine numbers. That way we can tell you if it is a '71 or a '72. A few things on it look like '71 at first glance.

In your clip, one thing I hear is intake noise. Your air cleaner covers are swapped right-for-left so that the rubber hoses are not connected between the air boxes and the carbs. Here's mine:


Hope that helps, others may comment with different views, I expect,

Kurt

PS -- My bike was a total rat when I got it, then after cleaning it up, fixing it up, and getting it running, I rode it 20 miles, then decided to tear down the motor, and it is in pieces now, my winter project. In retrospect, I think it would have been better if I had taken it apart before riding it. I found broken valves springs, and the exhaust valves are very loose in their guides.

Sounds like valve clipping the piston crown to me

Sounds similar to mine which was that very problem.

Zoltan, it sounds like you are saying that the seller told you about the noise? I recall a BSA for sale recently on Craigs List in East Hartford I think it was, seller said that the motor had issues. Looking more and more like winter project time. More running just might cause more damage. I'm lucky that I didn't destroy mine in those first 20 miles.

-----i would definetly say --"excessive valve clearance"---take off the valve cover and adjust the valve lash----easy fix----dont get excited

It's only running on one cylinder, sounds like. All kinds of weird sounds can come out when that happens.

After running it a few seconds like that, one header pipe will be so hot you can't keep your hand on it, and the other will be stone cold.

Is that what's happening?

Lannis

Like others have said, start with the valve clearance and getting both cylinders running somewhat even. While the rocker cover is off, make sure the pushrods and rocker arms are properly seated. Also make sure the washers and springs for the rocker arms are installed correctly. Here is where you need a manual.

Good luck

Welcome to the forum! BSA's are the way to go! Looks like a 1971 model, could be wrong

And while you can run the bike without the rocker cover off it will be very messy.

Remove the rocker cover the primary cover and the spark plugs.
Put a socket on the big nut on the end of the alternator rotor and turn the motor over. Just sit , look & listen.
Every thing should go up & down in a nice uniform motion and be the same left & right.
Then close your eyes and feel with one hand on the head, left side then right side.
Every thing should be happening smoothly if you feel a click then you have found the problem

Don't be in too much of a hurry to pull the engine apart. Rebuilding a BSA is a major project compared to a Japanese bike. Check all the stuff listed above first. You may be able to fix it without splitting the cases.

Mine was making an awful clanking noise when I got it. Turned out it was a worn primary sprocket (the splines on the sprocket mounted on the crankshaft, on the left side.) If you put the bike in gear with the engine off and rock the bike back and forth and it goes 'clank,' 'clank', it may be a worn sprocket.

Wow, thanks for all the replies and suggestions everyone. Looking to get some work done on it this weekend and will then give an update.



This sounds just like it actually.

Yep I picked it up from east hartford at a flea market

Glad it showed up, when I pressed submit post on the iPhone all it gives me is a blank area.

Take the plugs out and turn the motor over slowly ( by the kicker is fine) mine made a ping when the valve touched the piston. I have a video of that somewhere.

See if this works.

Allan, its showing as a private video on my screen.

If it's not excessive valve noise I'd be looking at the pinion marks. These dashes, and one (crank pinion) dot must line up for correct valve timing. If they don't... it's trouble. Your inner timing cover needs to come off to access these.

Thanks Kommando, it should be visible now. Unfortunately I can't see them on any I device.



I disagree with the comment, with standard valves, cam and correctly recessed valve cut aways you can actually time the cam 1 tooth either way and it will not connect valve to piston, the problem I had was because I was using over sized valves with a cam which had a very wide lobe separation.

The cam being too far advanced by one tooth would give a lot of low down power
The cam being too far retarded would make the bike slow to get going and run better at higher revs.

Never assume anything is as it should be though. (Meaning bola could still be right)

So, since I've been on break I have gotten some time too work on the BSA. I plan on making this bike into a flat tracker with modifications done that can always be reverted back to the stock bike.

The image attached is a little old but I cleaned the carbs and put them on and the bike is idling well. The left spark plug was fouled and I think that was the cause for it not idling along with messing with the jets. The carbs probably didn't need a cleaning, good to do anyways however.

So I got under the cover and I found a free large washer I looked hard but it really didn't see a free nut or something of that nature or anything missing something like that. Not sure if the past owner just accidentally left it in there or what, but it is a little concerning. The valve clearances all checked out to spec but I redid all of them anyways and the knocking noise does seem less prominent but I feel like its still there and or now that both cylinders are running they're maybe muffling the sound a bit making the sound less prominent. No metal flakes anywhere or anything loose though. Now that the bike is idling, even with the engine issue its may be hard to resist to take the bike up and down the road since its going to be 50 degrees on christmas tomorrow here in NYC . Though, I may wait to not cause further damages and problems down the road, I will post a video of the current engine sounds and I have my fingers crossed its just normal bsa valve noises.



left side:

right side:



Also need a new gasket

You don't need to open the timing case to check valve timing. You can check it if you remove the rocker cover.
Bring the engine to TDC. On one cylinder, both valves will be open a little over 1/8". The intake valve should be open slightly more than the exhaust (maybe 0.040" more), but they will be close to the same lift. If you're out by one tooth, the difference in valve lift at TDC will be huge, more like 1/8".

"I plan on making this bike into a flat tracker with modifications done that can always be reverted back to the stock bike."

Zoltan, this is a whole nuther ball of wax, unless perhaps you meant "street tracker". If you really meant flattracker, and you want to be competitive, even in vintage racing, you might as well tear it down to nuts and bolts right now, and you'll undoubtedly have to make internal engine modifications that will be more or less irreversible.

Haha, yes I meant aesthetically, I'm in no shape to make or even know to make race modifications for this bike, maybe eventually though

Though, after I fix the engine clammoring, I do plan on tearing the bike down and doing a frame up rebuild painting and re-nickeling things, as well as removing excess weight.

Allan, how did you go about fixing this? Was it caused from excessive valve clearance?
I've gone through my clearances twice as per the manual directions, my clearances are good. However it really sounds top endy, I'm hoping it isn't piston slap.
I probably really shouldn't even be running the engine but some things I've came across from messing with the bike:
(bike is very lean running)
-small white smoke coming out of right carb (idk if this has anything to do with it not running for many years)
-major kick back from the kick pedal when try to start it sometimes, could be the timing is off?

The noise I had was the over sized valve clipping the piston, the wide lobe wide seperation high lift cam combination was the cause, a change to standard valves worked better with the cam I had fitted.


Any spitting back through the carb is a lean mixture as you have surmised. I run with 010" inlet and exhaust for valve clearances ( years ago in one of the classic mechanics mags there was an article covering the spitfire cam stating to run .002" bigger clearence for improved performance, and the book settings for a reduction in valve noise) the settings I run work the best out of what I have tried ( and I have tried a lot of different settings) I also don't find any increase in valve clatter. This being the case I don't see valve clatter being your problem but I wouldn't rule it out until you have checked these settings but .002" either way won't make a difference, a heavily worn valve train ( everything from cam pinions to cam lobes and cam followers) will show more clatter than a slight gap increase.

I'd start at the top, checking everything is within spec, removing rocker cover and working down till the head is off.

Serious pinking being from lean mixture might be the noise your getting, is the noise worse under load?
Lean mixture could simply be from an air leak around the carb mounting, spraying some wd40 or some "easy start" will show this up as it will effect the idle speed.

Incorrectly set pilot mixture could also be your cause of lean mixture conditions.

Hi Zoltan,

Welcome.

There are large flat washers in the valve running gear. They are next to the spring that holds pressure on the valve rocker on the rocker shafts. It's easy when re-assembling the valve gear to lose the flat washer. Get a parts manual as well as the shop manual so you can see how things go together.

Also there is a slim chance that one of the lifter retaining circlips could have come off the lifter (there are four of these in new motors) and is bouncing around down at the bottom of the pushrod tunnel. Most people put the lifters back in the bike without the circlips. Fish around with a long magnet to see if there is anything down in the bottom of the pushrod tunnel.

BTW - When setting the valve clearance on the BSA, for setting the LH exhaust valve, rotate the motor untill the RH exhaust valve is fully down (open) and stopped and then set the LH valve clearence. Same for the intake valve. I'm using .010" for the exhaust and .008" for the intake.

There is one other possibility on that valve noise: no oil to the head. On the back of the head there is a thin oil line. Remove it at the head and crank the motor. Oil should start dribbling out in a couple of seconds. If nothing comes out then there is your problem. No oil to the head would make that noise I heard on the video.

How many miles do you think are on this motor?


Regards,

PS - the OIF BSA is the Best handling BSA out there. Was this the bike that was on Craigslist the last year up in Connecticut?