James ML with no spark

[ramwing7]

I have a 1947 James ML that won't make a spark.
I have had the flywheel re-magnetized, installed a new coil, rebuilt the points with new fiber washers, honed the points themselves to remove pits, installed a new condenser, a new sparkplug, and replaced all ignition related wiring and still no spark.  The timing is spot on as best I can understand from the Villiers manual. 
It may be that the flywheel is not going onto the crankshaft far enough, but I don't have a reference to determine this.  It looks like the lighting coils are only covering about half the magnet.  It is about 1.5 cm from the outside edge of the flywheel to the front edge of the ignition armature.

Does anyone have any pics of a flywheel in place or any other suggestions.  I'm pretty much stymied at this point.

[33d6]

The James ML was fitted with theVilliers 9D engine. This 125cc unit was introduced in 1936 and made up to1949 being steadily improved and upgraded over that time. The complete unit is totally interchangeable but not necessarily all the various upgrades. This can lead to interesting problems such as yours.
Before we start could you please provide a little more information such as the engine number and whether it was running when you got it. Do you actually have a manual for it? What is its history? Anything else we should know?
All very dull I know but the more information we have at the start the sooner the problem may be resolved.

[R]

I have a (postwar) 9D, but not in an ML

Does it all look OK externally ?
https://oldthumpers.wordpress.com/wp-content/uploads/2010/12/06092010109.jpg

Could get some pics, but not yet familiar enough to know where to compare ?

[ramwing7]

Attached are some pics
As you can see the engine number is 539/8831.
The bike had intermittent spark before I disassembled it.  By that I mean some days the kickstart generated a good strong spark.  Other days, nothing.
The bike was a project started by the previous owner.
The coil is new.  The red wire connects it to the points.
The condenser is externally mounted and has tested good with a multimeter. It connects to the stationary points by the green wire.
The points show no continuity when open.  Continuity is achieved when the points are closed.
The points are original and have been filed and honed to remove all pits and restore to flatness.
The flywheel is mounted with the piston at TDC and the arrowed mark on the flywheel aligned with the mark on the backing plate (near the high-tension lead exiting the backing plate).  The points open at about 5/16" BTDC.
That's what I know.  That and I have no spark.
Am I missing something obvious?
Thanks.
p.s.  I have two manuals   

[cardan]

It may be that the flywheel is not going onto the crankshaft far enough, but I don't have a reference to determine this.  It looks like the lighting coils are only covering about half the magnet.  It is about 1.5 cm from the outside edge of the flywheel to the front edge of the ignition armature.
Does anyone have any pics of a flywheel in place or any other suggestions.  I'm pretty much stymied at this point.

This doesn't sound right. The pole pieces in the coils should be centred on the magnets in the flywheel, and presumably the flywheel should sit quite snugly with its backing plate. If the flywheel is not riding on it's key, it might be a mismatched flywheel? The tapers should match such that the when pushed home the flywheel is firmly located - no looseness or rocking - even before the nut is tightened.

Leon

[Vreagh]

It may be me and the angle it's pictured but the two wire terminals look like they are under the screw head rather than between the insulating washer and contact carrier.

[ramwing7]

First of all, the pic above was most helpful.  Thanks.

Second, you're right the connector is below the screw head not the washer.  It was the only way I could figure to isolate the point carrier from being constantly grounded.  I'm going to have to locate a different connector to fit over the shoulder on the washer.  Otherwise, the wire contacts the screw and permanently grounds carrier. Going have to be thin connectors because those shoulders on the washer are not very big.
I think my goal is to get no continuity between the points when they are open.  Right?

Also the flywheel on a Villiers 9D is not keyed.

[ramwing7]

I now have connectors that do not touch the screws and are attached below the fiber washer.  The point holding plate is now grounded at all times regardless of the points being open or closed.  The ground seems to be coming through the wire going to the coil.
More research required and I'm going to see if I can find a shop to test the coil even though it's new.

[chaterlea25]

Hi,
That is correct the low tension winding is grounded at both ends, one permanently and the other through the points..
If you remove the wire to the coil you can test the contact breaker , one side should not be grounded when the points are open.
The magnetism creates a current in the closed loop of the primary coil, when the points open the magnetic field collapses
the change in the magnetic field creates the high voltage to spark the plug

John

[33d6]

Thank you for the confirming information and photos.
Further to the advice already given the middle photo seems to show the red wire being crushed with a possible cut through the insulation. Instant failure if it has. It needs to be laid down deep and as close as possible to the back plate. There must be no chance of contact with the rear of the flywheel. I also believe its current location is preventing the flywheel from seating properly hence your problem there.

Villiers also fitted a rubber grommet where the red wire enters the points box so as to eliminate any chance of a short circuit occurring. You now have the additional green condenser wire coming through the same hole. I would think carefully how you could improve the present layout.

The external condenser is an old and successful competition mod. There are a few others I could list if you wish. All aimed purely at improving reliability and dependability.

Finally, wear in the moving points pivot hole causes the ignition timing to wander back and forth. Check yours for wear. Later points boxes are bushed and bushes are available from Villiers Services. Space is tight but if you have the facilities it is possible to rebush the early bronze boxes. Sloppy timing reduces power.

I think the coil is fine, your red wire is the problem.

[ramwing7]

Thanks for the info.  It's helped me understand when the points should be grounded (I think).

I have replaced the red wire entirely and routed it behind one of the lighting coils so there's no danger of flywheel interference.  The green wire will not be a permanent fixture since I have one of the Villier's square condensers somewhere in the mail.  It may be until after the holidays before I can sneak back to this project, but I'll keep things up to date as they happen.

Happy Holidays to all!!