Britbike forum Forums Thread Like Summary - timing mark on crank

quick question on timing, im installing a pazon ignition on my 1968 Spitfire engine and when I lock the crank in position with the tool that goes in front of crankcase, is that TDC or is that 34 degrees BTDC with tool installed into groove in crank? thanks

The rotor's not back to front is it? Just a thought...

71 WSM gives 34- 36 degrees BTDC as ignition timing.

If you have the stock ytpe alternator the rotor should have two raised bosses 180 degrees apart, with a clearly scribed line, no 2 is the correct strobe mark. What Koan says ,check its not on back to front.

The thread is regular, a rattle gun will do it.

Don't take it off needlessly, you will be able to feel the raised bosses on the reverse side with your fingers, if they are there.

Or use a dentists mirror and torch.

If you're making you own timing mark, I don't think it matters which hole the needle is in.

If you loosen the rotor nut, be aware it needs to be re-torqued to 60 ft.-lbs. This is necessary to properly pin the crank and shims to the main bearing.

In lieu of a rattle gun, put the tranny in gear and stand on the brake pedal as you tighten the nut.

Your right Mark for 68... Early A65's and A50 cyclones used 37 degrees BTDC timing, the timing tool came in c1965 and had a marking both sides to highlight which direction the tool should be (some aftermarket tools dont have these stampings)

By about 66/67 all timing called for 34 degrees, the factory probably felt this suited the bikes rolling out of the factory as proven by the numbers on the dyno. It was also about 66 that they started using larger port heads (might have something to do with the port change or could just be coincidence) it was about 67 that the strobe timing inspection window apeared on the primary cover.

I beleive early rotors which wouldn't have had the timing marks were narrower than the later one so it would be interesting to see what you have.




I've seen this... God knows why the change...



As your not using a rotor with marks already showing, it wouldn't matter which hole you picked, as long as your line came inline with one pin...

The best way would be to mark with a ruller across the stator and rotor that way you know that when you have made your mark, you know the refrence for it is correct when strobe timing.