BSA A65 - a cautious test ride to assess this machine following adjustments and checks. 

I like watching how all of these investigations unfold, in my view Paul you do a great job of teaching the everyday enthusiast how to undertake a deductive analysis, keep it up 👍

It sounds like it's only firing on one cylinder. Might want to check the spark plug cap, it could be worn out. What a lovely part of England. Will have to visit one day.

Many years ago I drove a Mini which had similar characteristics and sounded like the proverbial "bag of nails". A full investigation showed that what I initially thought to be a loose flywheel actually turned out to be a crackshaft fracture. It had sheared through the centre (of 3) main bearing journals at an angle of roughly 45 degrees. The obliqueness of the fracture meant that drive was transferred across the break but it would not have lasted much longer without totall trashing the engine. It's a very long time since I saw the inwards of an A65 engine but it should be possible to get hold of both ends of the crank to see if there is any relative rotation, however slight. If there is then.............!! Got to be worth a shuffty.

These bikes are lovely and getting rarer by the day. Good luck fixing her Paul. You know how they work.

Sounds much better, less harsh.

Some of these bikes including that one looks lovely. I wonder are people buying them as renovated then finding gremlins like that one has. If you can feel it through the bars i very much fear big or little end of whole crank needing attention Paul. We win see hopefully for the owner i am wrong. Regards Billy

For myself this is a great joy to watch. My bikes are quite new and rather sterile whereas the old British bikes have real character almost living entities

Thanks Paul.

During your test ride, I got the impression that you were reluctant to give it a free rein. I thought it sounded alright until the tickover at the end, which made me wonder about worn bearings or gudgeon pins, given that you had already checked the valve clearances. Now I want to see what you find next. Its all the more fascinating because I don't have to do the work and its not my bike🙂

Still betting on Big End bearings - they might account for the timing seeming out as it stretches the stroke. Can you start putting times on for next video Paul 😄. Missing work waiting for these.😆

Its what it is paul..you sometimes just can`t postpone the inevitable! after the last few diagnostics,,the owner only has one easy choice, if it was my beezer i`d be happy to have you sort it ,,end of ! 👍😇

With the grande amount of diligence, effort and time that you are showering down on this power-plant, I be curious as to the "size" of the final bill. Tell me, cheri, how do you charge...a Flat Rate per heure ?, or a Set-amount, dependant on the specific job ? BTW, I appreciate how you keep the owners constantly abreast of your progress & findings.

Beautiful bike- hopefully the owner agrees to have the lump out to get it as nice inside as well

i had visions of an engine strip on this one. good on you for sneaking up on it. stealth of the cat springs to mind

Super interesting . How will it play out ? A great looking bike incidentally .

G'day from Australia, Paul vibration and any nocking, drop in power, you can expect too strip the engine down for a full understanding of the problem, hope the owner take your advice, cheers mate, Neil 🤠.

Keeping the revs sensibly low still sounded and "felt" like the worn out A65's I knew in the 70's & 80's Paul. What looks like a massive glob of gasket goo round the left exhaust collar reminds me of them to lol! I agree with you 100% mate, ride no further until you've had it apart, i suspect a worn bush and big ends at least, good luck with it!

Time to bite the bullet. The anxiety of not being sure is killing me. Primary drive, crank balance, big -end, main bearing etc has to be checked. Spanners out. Lets go..

Sounds a lot better but you still have the play found when you were checking TDC. I hope the owner allows you to carry on with a full rebuild if only for our, the viewers, sake.

Hi Paul , looking forward to more investigation on this bike , as you rode it ,looks like the forks are twisted in the stanchions maybe.

Looked like a first class ride. Though my hands aren't on the bars.

I'd go for HC pistons and a head skim/thinner pattern head gasket leading to slight advance of ignition causing the rough running.

Sometimes owning a classic is like trying to fill a hole in the road with money.

it not the bike , its the state of those roads ! 😀

I was talking to someone many years ago about ab a50 that was vibrating badly And had always vibtated badly It turned out that the crank shaft flywheel was fitted incorrectly ar the factory And when it was rotated on the crank to the proper location the bike super smooyb

Perhaps new big end bearings and a crank balance ?

Yeah, if it was my bike, I would want the dark bits looking at. The tick over at the end did not sound good.

There is something wrong. It went PAST the pub..😅

Crank out of balance???

Are any of these BSA's not suffering from crank problems?