AUTO ADVANCE AND RETARD

brian laud · Post by **brian laud** » Tue Sep 22, 2009 12:30 pm

On a 1956 g80 should advance/ retard unit be keyed to magneto or will taper hold it in place. Magneto has a woodruff slot in the taper but the advance retard unit bore does not have a keyway. i s it the wrong unit as it was not obtained with the bike . When I bought the bike as a non runner it only had a keyed sprocket at the mag end, no advance retard facility at all.

wilko · Post by **wilko** » Wed Sep 23, 2009 2:35 am

The slotted version is a dynamo sprocket. No reason you cant use it as long as the offset is correct. I'm actually using a maggy one on my dynamo!

Stan Palmer · Post by **Stan Palmer** » Wed Sep 23, 2009 8:20 am

Bryan said the magneto shaft had a keyway. My manual mag has no keyway. I guess it would be OK if it did have one, as long as the sprocket on the camshaft was free to enable setting the timing. Perhaps the auto advance ones had a key due to the extra torque possible from the rotating weight of the advance unit.

Stan

clive · Post by **clive** » Wed Sep 23, 2009 11:38 pm

I have two AMC auto advance units and neither has a slot for woodruff key, held on by the rather fancy bolt which also acts as an extractor. And you need it because the taper alone makes a good lock.

ktofthewoefig · Post by **ktofthewoefig** » Sat Mar 12, 2011 12:00 am

An old thread but i Just wanted to add Ive just removed auto advance unit from my 55 single. Found that the shaft had a slot for woodruff key but as stated above there was no slot in the auto advance unit and no key.Edited by - ktofthewoefig on 12 Mar 2011 12:58:23 AM

wilko · Post by **wilko** » Sat Mar 12, 2011 2:40 am

Someones homemade effort i guess. Considering most Maggy's are timed by positioning the sprocket on the taper. Perhaps the taper was worn from slipping sprocket in the past. Which i have come across on different BSA's and J.A.P's.