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Thread Like Summary
Bob E
Total Likes: 6
Original Post (Thread Starter)
#822892 09/08/2020 10:13 PM
by Bob E
Bob E
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
Liked Replies
#822925 Sep 9th a 12:27 AM
by koan58
The rotor's not back to front is it? Just a thought...
1 member likes this
#822928 Sep 9th a 12:43 AM
by gavin eisler
gavin eisler
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.
1 member likes this
#822933 Sep 9th a 12:49 AM
by gavin eisler
gavin eisler
The thread is regular, a rattle gun will do it.
1 member likes this
#822939 Sep 9th a 02:01 AM
by koan58
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.
1 member likes this
#822943 Sep 9th a 03:05 AM
by Mark Z
Mark Z
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.
1 member likes this
#822969 Sep 9th a 12:00 PM
by Allan G
Allan G
Originally Posted by Mark Z
The timing slot in the flywheel is at full advance (I thought it was 34 degrees Allan).

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.

Originally Posted by gavin eisler
71 WSM gives 34- 36 degrees BTDC as ignition timing.

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

Originally Posted by Bob E
Thanks Mark, of course this rotor that the builder used has NO marks on it. so I will have to make a line to coincide with the pointer. speaking of pointers I have to have the pointer in the right side hole in the case, correct. my case has 2 holes for the pointer

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.
1 member likes this
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