Brightspark Magnetos

The moving point 2 and the housing 1 are earthed, and the static point 3 is live.

The static point 3 is adjustable and held by an earthed clamping screw 4 which is isolated from the live static point plate 5 by an insulating washer 6.

A cable 7 leading from the LT coil is connected to a terminal post 8 on the static point plate 5, as too is a cable 9 which leads to the condenser 10  located in the rear of the housing 1 (Pic. B).

The contact breaker assembly is mounted on the magneto back-plate (by a pair of studs 11) as too are the coils and their pole pieces. The back-plate is attached to the engine crankcase, and the whole affair is then covered by the flywheel, with its magnets embedded in its rim, mounted on the engine crankshaft.

The disc of the flywheel usually has apertures to permit access to the contact breaker assembly for cleaning and adjustment.

However, in the event that the condenser needs replacement, in the past it has been necessary to: (1) remove the flywheel from the crankshaft to gain access to the back-plate; (2) remove the back-plate from the crankcase to gain access to the nuts on the studs 11; (3) undo those nuts to remove the contact breaker assembly to gain access to the condenser 10; (4) replace the condenser 10; (5) reassemble everything; and (6) re-time the flywheel and the contact breaker.

All quite a chore.

However, with the Brightspark Universal EasyCap (and a bit of care/luck), it is possible to fit the new condenser and disconnect the old one without removing the back-plate or flywheel.

In essence the cable 9 for the old condenser 10 is cut, and the insulating washer 6 under the head of the clamp screw 4 is replaced by the EasyCap 12 (Pic C) after it has been shaped and drilled.

So, position the flywheel so that you have access through one of its apertures to the contact breaker assembly.

Remove the cover from the assembly, if present.

Then remove the clamping screw 4 and its washers. Be careful not to drop them inside the flywheel, otherwise you will probably need to remove it to recover them.

In the example shown in Pic D, there are two possible holes for the clamping screw 4, and it was the left one 14 that was used to achieve full adjustability of the points gap using the eccentric peg 15.

Other variants of the housing and contact set may differ.

Now make a mock-up of the shape you require, using some thick card or other suitable material.  Click here to download an initial template in Adobe Acrobat .pdf format. When printing it out, make sure that you use the print dialogue box and that the page scaling is set to "no scaling" or "100%" so that it comes out the correct size.

Fit the mock-up to the contact breaker assembly using the clamping screw 4 and its metal washer, but not the old insulating washer 6. Play around with the shape if necessary until it fits nicely and the full range of adjustment is available without anything fouling your mock-up board.

Again, be careful not to drop the mock-up inside the flywheel, otherwise you will probably need to remove the flywheel to recover it.

Now transfer the shape of your mock-up to the Universal EasyCap, and cut, grind and/or sand the circuit board to shape, and drill the hole. Check that the EasyCap fits and allows the required range of adjustment of the static point plate 5. Again, be careful not to drop anything inside the flywheel.

In this example, the bottom layer 16 of the circuit board is in contact with the static point plate 5, which is live; and the top layer of the circuit board is in contact with the clamping screw 4, which is earthed.

It is essential that the bottom layer 16 does not inadvertently touch any earthed part of the assembly. You should therefore chamfer the bottom of the circuit board along the edge marked 17 in Pic E so that the bottom layer 16 cannot touch the housing 1.

You should also countersink the hole 18 on the underside of the circuit board, so that the edge of the bottom layer 16 around the hole cannot touch the clamping screw 4.

The old condenser needs to be disconnected. In the example shown, the condenser cable 9 and the LT coil cable 7 share a common terminal tag. Using some fine side cutters, you can snip through the condenser cable 9 near the tag. Make sure that you snip the correct cable, and also make sure that the snipped ends cannot touch anything.

Adjust the points.

Replace the contact breaker cover if there is one.

Replace the flywheel cover if there is one.

Job done.