Auto Advance Unit Electra

Hi Ken, I became a convert to electronic ignition with in-built advance years ago. However, to start with, I did run with standard system on my Electra. 

I followed the advice of the Norton Twins workshop manual for setting timing. Nothing in there to answer your question.

I advise you to screw the auto advance loosely onto the camshaft. Put the points and condenser plates into position with adjuster slots mid position. Secure the two screws and two pillar screws. Use the proper washers.

Now, gap the contact breakers. Then

Turn the engine to TDC.

Loosen the auto advance and rotate it so that the cam is just opening the contact breakers points at TDC. Fiddly. Secure the auto advance in this position.

Now follow the advice on setting timing for Electra. Manual or this forum. You will need a timing disk and a piston stopper.

My experience of the Wipac points is that the securing screw is inadequate and the action of the cam moves the adjustable contact.

You must not assume your auto advance is 22 degrees. They start at roughly 22 degrees when new and then change with use and abuse. Note, the auto advance is stamped 11 degrees. But rotates at half engine speed.

I hope you find some good condensers.

Happy New Year

Peter 

Pazon or Boyer Bransden.

I wrote an article in the Dec 2022 RoadHolder (page 40) on timing the Lightweight engine  (Jubilee-Navigator-Electra) with Electronic Ignition.

If you want to time it using the original points & Auto-Advance (just to get it going), you need to follow my instructions as far as determining TDC (Top Dead Centre) are concerned. Then, on all models after 1960*, you remove the top plate & Contact Breaker and set the timing in the max advanced position, by moving the bob weight out with a sharp object. Very fiddly, but essential. The fully advanced settings are 32deg BTDC Jubilee, 24deg BTDC Navigator, 30deg BTDC Electra. These are VERY important (& MUST be checked with a strobe once running!).

Once you are satisfied that the lower contact breaker is set correctly to the max advaced position, let go of the bob weight and try to determine at what crankshaft angle the contact breaker is opening when it is retarded. In an ideal world, with all new components, the Advance unit moves the timing by 11deg, which translates to 22deg at the crank (cams run at half engine speed). Thus you might expect an Electra, set to 30deg BTDC advanced, would now show 30-22=8deg BTDC when retarded.

The reality is that slop & wear in the system means that this reading could be anything around that region, but its important to note exactly what it is!. Then you replace the upper contact breaker and set it to the retarded measurement you just obtained.

You must, of course, also ensure the CB gap is 12thou.

Assuming you followed this process correctly, the static timing is set correctly, and all things being equal, the engine should now start. Now the important bit - repeating the warning above - you MUST check the timing with a strobe, to ensure the advance mechanism does not go beynd the factory figures when you rev the engine. You now appreciate, perhaps:

• The importance of obtaining the exact TDC.
• Why people suggest moving over to Electronic ignition.

Good Luck!

*Jubilees 1960 & earlier did not have a removable contact breaker to allow access to the Bob weights. On these engines, one had to manually twist the cam forward to advance it, whilst attempting to set it on either contact breaker. Then, to balance any difference between the cylinders, the only adjustment you had was the points gap. I did hear anecdotally, that if you bent the fixed contact position, you could maintain the 12 thou gap, whilst moving the timing by a couple of degrees to match the other cylinder.

I put the timing disc on the engine sprocket, found TDC set the pointer and used a battery powered strobe. 

Dan