Britbike forum Forums British Motorcycle specific Brands Bsa bulletin board Brought home a B44SS, got questions

The two camps regarding electronic ignition (EI) each have their points (haha), but the EI brigade often makes it sound that EI is an absolute necessity, when clearly it isn't. Going back to the OP here, installing EI is not necessary to get the bike running, unless there is something sufficiently wrong with the standard ignition system that would make it uneconomical to fix it. On that issue, I would not automatically replace the existing points. Usually they can be cleaned up just fine and the quality is better than the new stuff.

Ed from NJ

Absolutely spot on. Adding EI at this stage is an extra complication and expense. Get it running, see what it needs and then add an EI if you just must.

It almost seems that some view it as a magic thing that will protect you from all British motorcycle troubles. Not true in my opinion.

Dunno if there's really 2 camps on this... I think different bikes warrant different considerations.

I finally got talked into a Boyer some years ago on a 441 that truly wanted to hurt me... still have the bike, and since the Boyer, no kickbacks (on the now occasional times that I kick it). No regrets.

Keith Moore years ago told me EI was only needed for twins, no need on singles... ironically I have a TR5T (twin) that is the easiest starting bike I've ever owned, and it is still on points. See no reason to change it.

An individual with some mechanical aptitude may disagree...

On unit singles I like EI's
Having ridden B 40's & a B 50 for a couple of decades , unless you replace both cam bushes the action of the followers on the cam lobes can make a cam running is a worn bush to bounce
Now because the points are further outboard of the bushes, any movement of the cam is amplified far enough to make the points open & close giving you phantom sparks and they will change their timing at different engine speeds
And the faster the engine revs the more the bounce
Not a problem with most EI's

You hear a lot about points bounce on British bikes, at 8000 revs they are only spinning at 4000rpm. I still have points on the 400/4 and that red lines at 10,000. As the points are mounted off the crank the points are working at 10,000 rpm too.

Points themselves aren’t the problem, it’s the quality of the ones being used.


I’m in the camp where on a single cylinder they aren’t needed. Some EI will retard further than points do so that might make starting easier. Though I’ve never found a problem, least nothing that isn’t carb related. Points on a twin are more likely to go out of sync, so whilst it isn’t needed for. Twin to run better, it saves a lot of spannering time. Which is why I went for EI on my twins. Get me a decent set of points and I’d happily use them.

Ever looked at a set of points with a 'scope at 3000rpm?
Specially with bushes that are slightly worn........

EI has been around for 50+years so it's classic enough for me.

Yes, exactly. The point of my original question, back on page 1, was to understand the AAU spindle dry-lube - which I'd still like to understand. Discussing the merits of EI, including electronic advance curves, is fine and educational for me but I'm in the "get 'er runnin" camp here. Not going to do anything too proactive. The points look good, gap is good, did a "dollar bill" cleaning, absolutely will not disturb the timing until I have a good try to start it as it sits.

OK, now, carry on...

Jim,
I would check the timing statically. It is easy enough to do. Just make sure that you have set the point gap first. Then, there is a plug in the front of the engine. Remove it and turn the crankshaft until the points are close to opening. Peer into the hole from the plug, there should be a hole in the crank in the vicinity. Move the crank back and forth as necessary until the hole in the crank lines up with the hole in the crankcase. Most folks stick a screwdriver in place to hold it in place. Ground the alligator clip on your continuity light on a cylinder fin and put the point end on the ground side of the points. The bulb should be off. Assuming it is, with your other hand, using a flat blade screwdriver in the notch of the points cam, rotate the points cam to the end of its travel, the continuity light should go off just as you reach the end of the points cam's travel. If not, adjust until it does. You can rotate the entire points plate, or use the eccentrics on the plate itself. Shouldn't take more than 20 minutes

This is a genuine weak spot with replacements for the outer bush the biggest problem. It is sintered bronze and often won't hold a secure press fit. They wear, come loose in the case, and have a negative effect on ignition reliability because the oil seal can't cope and the points get oily. IMO, sloppy cam bushings are a good reason to split the cases because for a good repair they should be line reamed. Also, often an oversize one has to be made because the housing in the case has worn.

So Jim, the way you check this is to set your piston at TDC compression stroke and then see how much you can wiggle side to side and up and down the end of the point cam and bolt. It will usually wiggle a little but if it wiggles a lot, you need to think about new bushings.

Absolutely, but don't bother with an old set of points, replace them first.
Then all you have to do is:- repeat once you have it firing, repeat after a couple of hundred miles, remember to oil the little felt thingy (but not too much or you will f**k the points), clean and adjust points every 22.73 miles (better than the old Villiers motors, they were every 21.73 miles) or "at intervals" according to the book, retime again every 1,000 miles (yeah, the book says every 2,000 but this was from the era where Philip Morris said tobacco was actually good for you). Replace points and condenser "regularly" whatever that means . Oil the AAU pivots "regularly", but again not too much or ......

or alternatively ..........................

That's a strange comment, most EI's can be repaired quite easily.
I must have done about 30 Rita's over the years, as for Boyer and the encapsulated ones,
they are fiddly but normally it's the output device that packs up and can be replaced.
Funny but the chances of an EI failing in service are far less than say the points leg breaking
off the points, try repairing that on the side of the road...... The answer i suppose is 'carry a spare'
but then the same can be said for EI eh? The 'black box' is a similar price to an AAU unit.

I wouldn't bother with new points if the old ones can be cleaned up. The nylon heel on the new ones wears quickly. The old ones last with a smidge of ignition grease on the points cam and an oiled wick. If your points do not have the wick, get one. I used to buy used original points for next to nothing at swap meets. Folks assumed that a tune up automatically meant changing them. Not so, the usually have plenty of life in them. I don't buy them anymore because I have plenty to spare. Good luck with your project.

Ed from NJ

No Al.
It is not the points bouncing or fluttering as they do at high revs but the entire cam shaft flicks up when the load from the valve springs is released
And that little flick can be enough to cause the points to flic open so you get another spark
As the cam gear wears more & it is the outside one that causes the grief the cam sill move down as the valves start to open then up as they close so you get sparks all over the place .

So the fault being with the bushes supporting the pinion and not the points.

A change of bushes on any bike (single or twin) would likely never need replacing again with the miles these bikes tend to see now.

Ed, you're right, I will check the static timing. The plug - is it the one on the upper RH side? I can't find anything in the owner's manual or workshop manual that identifies that plug. Does lining up the crank hole give me an index point for full advance or idle? The workshop manual procedure that uses the witness marks on the generator rotor to set the timing for full advance.

It is a relatively large bolt facing towards the front and upwards in the front. It is on the same side of the engine as the primary cover. The plug in the front on the timing cover side is held on by 2 screws. It is for the optional tachometer drive. It is not what you want. The hole in the crankshaft is at maximum advance. The hole is considered to be much more accurate than the lines on the alternator rotor (you have to get your lingo right!). Obviously, you can check the lines on the alternator rotor when the hole is in the right position. The lines on the rotor are for checking timing with a strobe (timing light). Personally, on a single, I find it quicker and easier to check it statically. In your case, you don't have the engine running yet, so you have to do it statically. By the way, there is a mistake in my description, the continuity light should be to the feed (spring) side of the points. Good luck!

Ed from NJ

Yes, I understood what you were trying to say about the continuity. I found the plug and got the crank hole lined up. So if that is the maximum advance then I need to get the cam rotated against the advance bobweights and springs. Any suggestions on how to do that? Do I have to take the breaker plate out to turn the advance and lock it in place? I can't get much of a grip on the cam itself. Also, I took off the cover to the, ahem, alternator, and those marks are off by about 1/4" from where it lines up on the crank hole.

Jim

Is the rotor pointer in the correct hole?

With engine at full advance position, use a pair of small needle nose, one side in the notch and the other against the low spot on the point cam to rotate it against spring pressure to full advance. Have your test light hooked up and powered and watch for it to turn on or off depending on how you have it wired. Say for example your test light is connected to the point spring and have the bike powered up with the key on, the light will illuminate upon point break. If at this point you can wiggle the point cam a bit and make the light go on and off, you are very close and good enough to start it up.


First verify that you are at the correct spot. If the marks are still off, the rotor has probably loosened on its core. This makes strobe timing inaccurate and also sounds like a bad/expensive lower end noise. It could also be a wrong rotor.

The bushes, the gears, the AAU, the points, the springs, the capacitors etc ALL need maintenance to get
reasonable operation, although it will never be as good as electronically sensed/controlled ignition. That's
why they don't use them anymore!

Whether it is this or something else... I once had a partially sheared rotor key give me false timing readings and it cost me a set of Triumph 650 pistons on a fresh top end... Trust, but verify your timing. The crank and piston in compression stroke don't lie.

DJinCA

On Unit singles with the plug in the driveside case (69 onwards) for checking the timing, the crank only has one hole and when lined up its at the fully advanced position so you only have to get the piston on the compression stoke. Its very accurate unlike the alternator rotor.

OK, well it seems like I need to eliminate some unknowns. No problem but I am otherwise busy for the next few days. I will get back with answers.

But, one more question first. The hole in the crank flywheel that lines up with the port in the crank case - I don't see that mentioned in the workshop manual? In the spare parts list it is called the "timing aperture." Is there a reference that discusses this?

Thanks - Jim

Sorry Nick, I was being “tongue in cheek”, all the maintenance is why I went to electronic ignition in the first place.

You need the later manual

https://www.bsaunitsingles.com/Arch...70%20Workshop%20Manual%2000-4176%20x.pdf

PC is acting up so can't open this file and scroll but its in there somewhere. But regardless you remove the cover and with a 4mm allen key you slowly move the crank until the 4mm allen key finds the hole or use the mk1 eyeball, then adjust the crank finely to get the allen key perpendicular to the flywheel by eye. No special tool needed.