Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Messages - Martin

Pages: [1] 2
Twins / Re: BSA A50 1962 CLUTCH STICKING
« on: 08 December, 2018, 19:49:15 »
The oil for the primary chaincase should be a 20W50 mineral oil; the same oil that you use for the forks.

I spent a lot of time getting my A65 clutch to operate properly and, assuming there's little or no difference in principle between that and an A65 clutch, suggest you place all the clutch plates into a bath of clean petrol, leave them there overnight, then remove them and wipe the petrol off with some clean linen and allow the rest to evaporate. That done, wipe the bonded plates very lightly with fresh 20W50 - too much and they'll stick to the driven plates, which should be left dry. You want them so that they'll slide freely when you apply the clutch lever. Replace the plates and don't over-tension the springs. The clutch nuts on my bike sit proud of the bolt heads, making application of the clutch lever much easier.

I've had no clutch problems since. Best of luck.

Twins / Re: Bsa A65 spitfire
« on: 02 October, 2018, 17:23:27 »
Have you changed the oil lately?

I recently had much the same problem with my A65 Lightning. I realised belatedly that I hadn't changed the engine oil for some time, so you might try draining the tank and sump altogether, flushing the filters and checking the sump ball moves freely, then refill with fresh engine oil. I hate to think what sediment must have been arresting the flow back to the tank, but it cured the problem completely. Best of luck!

Twins / Re: A65/A50 Petrol Taps
« on: 11 October, 2017, 10:59:40 »
Chris - in case it's of help, I got my lever taps from Classic Motorcycle Spares and the elbow  clears the top fin of the cylinder head by about 5-6mm.

Twins / Re: A65/A50 Petrol Taps
« on: 08 October, 2017, 10:56:24 »
Hello Mr Editor,

Yes, there is room. I have 90 degree elbows fitted to the lever taps on my A65 (4 gallon tank). If I've misunderstood your question, please ignore!

Twins / Re: A65 cylinder flange cracking?
« on: 08 October, 2017, 10:27:14 »
I haven't seen any evidence of that on my 1968 A65, but that's maybe because it's done only 11k miles since new. The previous owner was a mechanic, so I'm assuming he tightened the head down to the correct torque.

Thanks for providing the sheet, as it shows the factory's specification!

Twins / Re: A7 ST petrol tank - best options to flush
« on: 26 September, 2017, 12:41:40 »
So far, I've had no problems with the tank on my A65, but that's possibly because of the low mileage the bike has seen - only around eleven thousand.

Believing that it needed a clean when I bought it, I used the products supplied by Tank Care Products, but refrained from going so far as to apply their sealant in case something else arose and I needed to clean it again. An awful lot of muck came out, and a couple of after-flushes of petrol got rid of the residues. It's stayed clean almost a year now with no protection, and there's still no blockages or build-up of sediments or rust that I can determine. Give Tank Care Products a try, but do follow their instructions to the letter.

Twins / Re: Stand Springs Woe.
« on: 15 September, 2017, 14:18:58 »
Yes, I did much the same as Bess.

If you could get the springs fitted without some form of lever, then they wouldn't be under enough tension and the stands might easily come down and hit the ground while you're riding. Both stands ought to retract with a pleasing "clang" and stay there.

Twins / Re: Simplified diagram of BSA clutch
« on: 26 August, 2017, 11:20:43 »

To a non-mechanical mind like mine, your diagram mirrors several sketches I made when I tried to fathom out the moving parts on my A65 Lightning 3-spring clutch, so you're not alone in resorting to the basics.

The clutch operation is really good now, even without the SRM modification, by tensioning the nuts so that only a light touch is needed on the handlebar lever, and after several exasperating attempts to get the plates to run in parallel I finally got them spot-on. I think that dealing with those two factors alone contributes more to the elimination of noisy clutches than anything else, in addition to the splendid advice I've had from experienced members.

Thanks, Bess and no, I hadn't seen that before.

All three clutch spring nuts are adjusted to round about the same degree shown in the illustration, and the plates are as near alignment as I can make them by line of sight.

I still don't know whether part of the ball should protrude from the end of the plunger but, if it should, then that's likely to be the cause of the crunching, as it's sitting well inside the recess and must therefore reduce the effectiveness of the pushrod on the pressure plate. As Julian says, new parts are comparatively inexpensive, so I'll replace what I've got.

Thanks again.

Thanks, Julian - you've given me a few other things to try. The ball doesn't want to come out easily, and that may be because it's worn and got stuck, but when it's out I'll measure it. The handlebar lever is 7/8", so the other type could do the job. Thanks again.

Twins / Plunger, clutch operating lever on a 1968 A65 Lightning
« on: 11 May, 2017, 10:22:40 »
I'm having trouble getting the clutch plates on my A65 Lightning to separate sufficiently, and should be glad of suggestions how to overcome this.

Part-cause might be the plunger, clutch operating lever (part 68-3065). Never having taken it out before, I don't know where the ball (part 65-2593) should sit, so I attach a photograph of the business end, from which it seems the ball might have worn so much that it has lodged deep inside instead of projecting further out like an egg in an egg-cup. My non-engineering thought is that, if the ball sat proud of the plunger's end, the effect might be to lengthen the push rod that little more so as to free the plates better but, against that, the pressure plate might then make contact with the chaincase. Where should the ball sit?

Though at its limit on the adjuster, the cable is in good condition and the slack is kept to a minimum. The push rod is 11" long and shows no sign of wear at either end, and the screw on the pressure plate has been adjusted to give the right amount of clearance between plate and push rod. The plates themselves have been cleaned in petrol (they were pretty grimy), they're perfectly flat and have no rough edges or anything else to impede movement; neither has the clutch housing - yet, with all this, I still get a horrid crunching noise whenever engaging first gear from neutral. All other gear changes while in motion are fine.

All helpful advice will be much appreciated as, apart from the plunger, I've run out of ideas!

Twins / Re: Non-branded supermarket petrols
« on: 03 March, 2017, 12:25:15 »
Crikey - I seem to have opened Pandora's Box with my enquiry!

Thanks again to everyone who has dealt with my post. What is probably obvious to those who have ridden classic bikes for years isn't to the likes of me, so your thoughts about fuels and their effects have been most illuminating, reassuring and worrying all at the same time. At least I know where to go to fill up! :)

Twins / Re: Non-branded supermarket petrols
« on: 26 February, 2017, 09:56:59 »
I never cease to be amazed at the depth and breadth of knowledge within the Club so, once again, thank you all for your comments. They're extremely helpful to the likes of one who has had a gap-41 years between riding A65s, and clearly an awful lot has happened in that time!

The tip about checking valve clearances rather than digging deeper is appreciated, Arthur. Something else that, with no mechanical background, I wouldn't have thought about.

Twins / Re: Non-branded supermarket petrols
« on: 25 February, 2017, 15:02:19 »
Thanks again, folks.

What little information I have been able to glean about my bike's history is that the previous owner gave it a top-end overhaul as far as the piston rings when he thought decarbonization was necessary, and I imagine he would have examined and dealt with the valve seats at the time - or at least I hope he did! The mileage reading is still under 11,000, and there's plenty of poke in performance terms.

From what you advise, though, it seems there's something else I need to look into the next time the bike is off the road, as I'd never have given the valve seats a thought.

Twins / Re: Non-branded supermarket petrols
« on: 24 February, 2017, 09:53:51 »
My thanks to you both for your helpful comments! Other than flushing the tank through with cleaning products to rid it of decades of rust and other muck, I haven't lined it against the effects of ethanol, so will take your advice and stick to the branded fuels.

Pages: [1] 2