Clipper Ignition Timing
Posted: Tue Jan 28, 2014 7:12 pm
Ignition Timing Reference Pointer 1959 250cc Royal Enfield Clipper
The information below is only intended for novice biker’s having little or no experience on setting ignition timing.
Make a reference pointer (plastic lid) & attach to the stator wiring cable clamp as shown in photo.
At T.D.C. on the compression stroke make the first mark on the rotor lining up with the reference pointer.
The second mark (to the right of T.D.C.) will be for 1/64†or 5 degrees for static timing.
The third mark (to the right of T.D.C.) will be for 7/32†or 30 degrees for advanced timing.
To work out the ignition timing try this, multiply the rotor diameter by 3.142 (Ï€)
My rotor diameter was 70mm x 3.142 = 220mm (circumference of the rotor)
Next divide 220mm by 360 (degrees) = 0.61mm.
Therefore one degree of the rotor circumference = 0.61mm.
Static timing needs 5 degrees so multiply this by 0.61 = 3.00mm.
Transfer this 3.00mm to the right of T.D.C. and that’s your static timing mark.
Fully advanced needs 30 degrees, so multiply this by 0.61 = 18.3mm.
So your last mark wants to be 18.3mm to the right from T.D.C.
When using the manual they ask you to turn the piston back 1/64†from T.D.C. this is ok if you have the cylinder head off, not so easy when the engine is fully built & you do not any experience or have dial clocks / callipers etc.
This is not as difficult as it looks, read it over a few times till it sinks in, the main thing is to make sure your T.D.C. is spot on! Do not go over T.D.C. (Try Hitchcock’s T.D.C. tool)
This works on my Clipper no problems at all.
Alter timing measurements to suit different machines.