BSA A65 vibrations - basic investigation work begins.

It is always best to cover the simple stuff first, and some of that is seen and discussed here, although while perhaps the scavenge strainer wasn't quite 'spotless' - I was a bit too kind with my description - there were only a few small particles of gasket type debris on it and nothing to suggest the engine was trying to self destruct!

[@jiyushugi1085]

When I rebuilt my A65's engine I used lower-than-stock-compression pistons (about 8.5:1), had the crank dynamically balanced and fitted taller the stock gearing and electronic ignition. Starts first kick, minimal vibes and hauls ass on the highway. Have put many happy miles on it and it's still going strong. It's not the bike, it's who's spinning the wrenches that matters.

[@colintownsend5024]

Thanks for taking us with you on this investigation looking forward to the outcome.

[@brittweir8844]

Ditto that👍,

[@jlh2701]

As we keep saying, every day is a school day, we never stop learning, good work so far👍

[@timeinthepast]

Those rotors are notorious for. Their centers working loose and could explain timing differences

[@wdhewson]

Looks cracked at the core.

[@wdhewson]

I had an A65 fitted with high compression pistons which was harsh when working hard. Eventually the LHS piston disinegrated with unhappy results.

[@tjr1064]

My a65 is suseptable to engine mount bolts as well - buzzes if those loosen up. Like you said little things can add up. Great to see you have a penchant for a65's as i've learnt heaps from your vids - cheers

[@geoffreybennett2457]

I seem to remember that the pin in timing cover should be in right hole for about 34° btdc, the left gives 38° btdc....if the crankcase had the timing plug hole in front take it out and locate flywheel in correct position.........coming up to firing point and see if the mark on rotor line up... It's years since I did A65s so my memory may be wrong. PLEASE CHECK. Nowadays I just stick with my 350 bullet.... Nice :)

[@stuartburton1167]

Fascinating to watch you doing detective work

[@marshalmercer594]

Thanks for keeping us informed as to your progress.

[@norsehall309]

G'day from Australia, Paul, l have no dought you will find the problem if the bike has one, the next ride will tell, l think a rebuild is needed, cheers mate ride safe, Neil 🤠.

[@DrRobert7898]

That happened to my Crusader many years ago when a spring broke on the auto advance unit it suddenly felt like a road drill

[@andrewwolf4430]

Nice bike. I restored a 66 spitfire. Didn’t like the small tank so I put a large on on it

[@neilmcintosh1200]

Will you check the alternator and crankshaft keyway for play, or even play in the rotor itself?

[@AB-bf9ne]

😃I might have been right - small ends tend to shatter. This is so interesting! Or could be new rings on a very worn piston - had that before.

[@441rider]

So many rotor casting and variation could have had it hot timed. I had that issue I think after time we have to compensate. With points I always make a witness mark of running fine then I can go back to the scratch if way off.

[@dufus7396]

The red and chrome tanks ,side covers...the most styish Brit bike ever

[@hermangibbs8163]

Beautiful machine. Great trouble shooting. Thanks!

[@deltabluesdavidraye]

Tomorrow 😅 I am headed to Texas to pick up a 99 case iron Bullet.

[@williamnethercott4364]

If that engine has been running over-advanced for some time, would that contribute to wear in the big end and/or small end? My gut feeling is that it would but I'm enjoying being a passenger on your journey to getting the best out of this A65. I had never considered them as being desirable bikes but your videos have convinced me otherwise! In my own defence, I had taken a dislike to them because of false and ill-informed opinions I was given way back in the 1970s, by somebody who thought Mr Honda walked on water but ended up riding a T120 himself. I should have revised the value I put on his opinions years ago. Good luck with fettling this one!

[@sicks6six]

in the first video, I suggested the wrong pistons could be the problem, or something is worn out completely in the stator plate set up, worn shaft, loosened and worn holding pins, something mechanical isn't as it should be, engine out the frame a tear down I reckon,

[@shanedykes7841]

Hi Paul did you try your tool in the right spark plug hole and compare any differences with the pistons on the up stroke and then down stroke. The timing marks might be closer when using the right plug hole, which would be bad. Also my spitfire with the locator pin through the front of the engine which locks the crank at 34 BTDC, I have a rotor mark about 6 degrees over advanced.

[@thepipesmokingbeekeeper8917]

Good work very interesting

[@Katie-n4o]

HI, I'm interested of the t-shirt BSA with red letters you are wearing. Could you please tell me from where I can buy one?

[@paulhenshaw4514]

That was a generous gift from a subscriber in the USA.

[@progvinyl9021]

Very interresting videos 🌝

[@philrulon]

Timing side bush?

[@colinhall8998]

Has the cylinder head been off and new gasket fitted? Sounds like the pistons are hitting an under sized head gasket, I’ve seen that before.

[@paulhenshaw4514]

It is certainly possible - I too have seen that one before!

[@grahamseward1388]

I retarded my A65T 5 deg where the crankcase plug was saying it needed to be, couldn't strobe it as I didn't have the inspection hole in the primary cover, someone told me modern fuels burn faster so that makes the difference, ran much better anyway. Still to much vibration so I've had the crank dynamically balanced it wasn't far out statically but one side of the crank was way heavier introducing yaw will see when I get out back together

[@colinmartin2921]

Engine sounds very knocky.

[@Fbunch-hm2ni]

Thats what hes checking

[@TrustMeiamaD.R.]

I see the problem..Lucas...😅

[@butlindsayforge5403]

Very fragile engine...a needle roller conversion on the timing side main is a start

[@paulhenshaw4514]

Assembled correctly and well maintained, they are not fragile and can do high mileages on their timing side bushes.

[@jiyushugi1085]

I made an alt-bronze bush for mine and had the journal hard-chromed. Still running strong.

[@andrewazur8629]

So I guess this bsa model is the bad one

[@paulhenshaw4514]

Not really, there are just a lot of them about which have been badly rebuilt.

[@andrewazur8629]

@@paulhenshaw4514 classic bikes could be selling bikes like that