Broke down on way home from Work today...

[Rob Valdez 79 R65]

I pretty much ALWAYS burn my arm when adjusting the dwell.
Perhaps a welding glove?

Do you have a timing light?

[Barry]

I adjust dwell by sound turn back to where I had previous, full lock clockwise and it idles good.Burn Arm on Exhaust.. put front cover back on, will not start?Take off cover bang knuckle on Shock, add oz of Blood, Bike starts ? ?Notice condensor wire that goes to coil has/had been pinched and is quite brittle.Replace w/cable from parts bike, starts and runs. Button up bike.Go for a ride, idles good, but does not give good power and pops and sputters....Reminder always add blood..  

Sounds like you are getting there so a little blood is a badge of honour.

Just for clarification dwell is a measure of the length of time that the coil has to charge up. Dwell hardly matters much on an airhead because on a twin the coil has plenty of time between sparks to charge up enough (that is reach saturation). You don't need to worry about dwell as long as the points are opening up enough to give a good spark. Anywhere between 0.014" to 0.020" will work fine but it makes sense to target say 0.18" to allow for wear on the points heel closing the gap a little between services.

Adjusting the points gap changes both dwell and spark timing .

Rotating the bean can adjusts only the spark timing and not dwell.

[jg928s4]

Now that I know it runs need to go back to the points when time permits.  Just wish I had the special points tool, got to be a contortionist to lay down, get my head between the forks  and front of the engine and look into the bean can to gap the suckers.  Any "Pointers"?

[Rob Valdez 79 R65]

Just wish I had the special points tool

Are you talking about this special points tool?



It only works on pre-beancan Type 247's (our bikes are Type 248).

The easiest way to set the point gap on the beancans is to remove it from the bike and do it on your workbench.

[Barry]

The easiest way to set the point gap on the beancans is to remove it from the bike and do it on your workbench.

I agree. It's much easier on the work bench and there is no disadvantage in doing so as if you changed the points gap the timing will need adjustment anyway. Another thing to be aware of is if you set the points gap with the outrigger bearing plate removed the gap will change when it is refitted.  On the bench it's not too difficult to set the gap with the bearing plate in place where as it's near impossible with the bean can on the bike.

So all in all it's really no more work to remove the bean can.

[Rob Valdez 79 R65]

On the bench it's not too difficult to set the gap with the bearing plate in place where as it's near impossible with the bean can on the bike.  

And measuring the gap with the bearing plate in place is much easier with a set of tapered feeler gauges like these:


_{inage borrowed from MikesXS Supply}

[Barry]

And measuring the gap with the bearing plate in place is much easier with a set of tapered feeler gauges like these:

Yes I have a set like that and I also remove them from the holder so that they can be used individually.

[jg928s4]

Bad news, when I removed Bean Can found a few little parts between it and the bottom of mounting point of front cover.  A little spring, piece of metal, the bean can inspection coverplate and a little plastic piece.  The Bean can sounded like a dampened baby rattle when I removed it as well.  I looked in the inspection point and saw similiar spring, I removed Point carrier to look inside and there is broken metal, missing part etc.  Pretty Jacked up, surprised the Bike even started.  Anyone hear of this failure before?

[Barry]

Anyone hear of this failure before?  

No never heard of the advance mechanism coming to bits before.

Are you sure it's actually broken and not just the spring having come off leaving the bob weight to flail about ?

I see you are looking for a new bean can but it is possible to remove the points base plate to get at the advance mechanism. From memory there is one screw to remove then the base plate has to be rotated to release it from crimps in the side of the can. On my bean can at least it was held in very tight by the crimps and in order to rotate the plate I had to make special tool similar to a pin wrench.

[jg928s4]

One of the points where spring mounts to weight is definetely broken.

[Barry]

One of the points where spring mounts to weight is definetely broken.  

Except for the springs spare parts are not available for the points bean can. Someone with the right skills could repair the part or make a new part perhaps at less cost than a replacement bean can.

[tvrla]

I've heard that some foreign cars used these same bean cans. I'd look into finding one of those.

I agree with Barry, it should be possible to repair the post, or whatever is wrong with it.

[jg928s4]

spring mounts to post pressed into a centrifical weight.  were post pressed into weight, weight broke.

[fermin]

So if I understand this correctly, on my 1984 with electronic ignition I can replace the 5k with 1K ohm wires, install Iridium resitor plugs and have the most powerful spark money can buy?

[Bob_Roller]

0 ohm caps would be preferred if you are going to use resistor type plugs .

I don't think 1K caps would cause any problems, I unknowingly used resistor type plugs (Bosch Platinum) about 20 years ago, didn't seem to make a noticeable difference .