Timing Boyer / Pazon

If you can accurately mark where the magnet or rotor is at 30 degrees BTDC (is that correct for an Electra?), then maybe your system could work.

Oil from chains isn't the biggest problem in the world though, and the alternator rotor is bigger than the trigger rotor and turns at engine speed, so timing to a mark on it will be much more accurate.

Ian,
The way I see it you need two accurate non adjustable points to check the ignition with a strobe. A fixed static pointer secured relative to the engine case and an accurate revolving timing mark relative to the crankshaft degree showing the required ignition full advance. But this is what you are trying to avoid.

Your idea uses two variable points. First, the rotor which isn't/can't be positioned at any accurate position, rather it is roughly set on installation. Second is the variable plate which is in effect the means of adjusting the correct firing point for the spark. You have no accurate datum to strobe and measure the ignition point.

I understand your thoughts but to me it can't work for my reasons above. Hope this helps. Stan

Ian, 
The timing procedure for Jubilee and Navigator with points is well described in the Norton Twins manual issued by AMC. 

I made an expanding mandrel that fits tightly into the crankshaft starter ratchet. An 8mm stud tightened things and provided the central mount for a timing disc. I thought removing the ratchet rediculous for a timing check. Photo attached. 

Obviously you have to remove the outboard starter sprocket and starter chain. 

Set the timing disc zero position with a piston stop. 

I find the Pazon can then be timed statically. 

And check the timing and advance curve with a strobe. The disc doesn't move if you keep the throttle action gentle. 

Peter 
 

Ian, 

Photo of timing disc on expanded mandrel with pointer.

With electronic ignition set correctly, you can forget about timing going "off" as with points. No need for inaccurate approximate paint blobs on the rotor. 

Peter 

Would it be possible to make a nut like the one in my first photo.  It has an external thread that the timing disc screws on to, second photo.  

A large diameter timing disc will give better accuracy than small diameter disc.  My disc is "adjustable" so I can use a substantial fixed pointer rather than a bit of bent wire.

This may sound like a lot of work for what may be a one-off setting.  My engine is a mixture of new, old and original parts, as they bed it may, or may not, alter the timing. I will check at some point.  Wear and tear might alter things, especially in a well used engine. 

One of the first jobs I did on the Navigator was fit a Boyer system.  I thought this is going to be a messy business, running the engine with the chain case cover off, oil everywhere.  needn't have worried didn't seem to fling oil at all.    

On my web site is a pointer I made from a scrap of aluminium, usable on all lightweights. this gives a fixed point. And stays on the engine. I then found TDC and (30deg) of the crank/rotor going round by 'hand' and marked the rotor. So when engine is fired up you can see the (30deg) point coming towards the fixed point with the strobe. I can't remember any issues with chains/oil flying about, or the starter sprag getting in the way.

I don't think your blob appearing in the hole is accurate enough.  My 250 had to be accurate to less than two degrees, just like the book says.

Scribe a line in the white paint, lining up with a notch or line in the plastic baseplate at 30 degrees BTDC, having turned the crankshaft forward to that position.

"There's no point (pun intended) trying to line up with the PCB as it must be able to move to adjust."

Yes, that was quite a stupid thing for me to suggest.

The advance/retard range varies between individual ignition boxes.

The fully advanced timing has to be correct and you don't know how far your Boyer or Pazon is going to advance until you have a strobe shining on the marks and rev it until it stops advancing (or stops advancing significantly).  That is usually around 5,000 rpm.

There is nothing wrong with revving to 5,000 rpm.  

It's noisy- so what!

It moves across the floor on the stand- put the stand on a rubber mat or a cut out bit of old tyre.

The only reason to set your timing according to the instructions is your bike might run properly.

There are loads of reasons not to do any job, if we set our mind to it.

In case anyone did not see Peter's response (The way the forum threads get updated means it appeared in the middle of the thread). Slightly modified, I hope you don't mind.

This is a very important point. If you use the disk mounted on the camshaft end rather than the crankshaft end, then one rotation of the timing disks represents 720 degrees of crank rotation.

As you are trying to set the timing 'spot on' then the inevitable slight jitter you will get even with electronic ignition means you are aiming for a middle range, so maybe +/- 1 degree.

Using the camshaft end means this becomes +/- 2 degrees.

Also remember, when you come to set the timing, The PCB circumference is about 200mm. So one degree on the crank is about third of a mm rotation on the PCB. 

Someone with skill can feel for TDC with a stick and also find where the points open, with fag paper or 1 &1/2 thou feeler blade, within a crankshaft degree.  Lots of people can't.

A strobe is still better, because points timing doesn't always behave itself as you rev up.  For example, any looseness of the moving contact on its pillar can send the timing all over the place at higher rpm.

I get 4.65 mm.  http://www.torqsoft.net/piston-position.html

I did own the lead balloon that was the Norton Jubilee.  Like everyone back then I timed it with a degree disc and something thin between the points.  Of course it worked, but it required a bit of sensitivity!

You've cast my memory back to setting one side advanced and one retarded, because the second set of points made the auto advance inaccessible.  I had forgotten that!

Some obsessives used a battery and bulb.  That was easier, but not significantly more accurate.

A skilled fitter (probably not me these days and not you, by what you say) can find TDC accurately enough with a stick.  You feel for what seems like a period of crank rotation around TDC where the piston doesn't move and use judgement to stop in the middle of that.  Of course if a degree wheel is attached anyway, it's only sensible to use that and a piston stop to find TDC.

Nobody said anyone would set the timing on a Lightweight with a stick.  Some sort of degree marks are the only sensible way.