E: Engine Mounting a Degree Wheel/Timing Disc

[Peter Holmes]

Robert's method gets my vote, its an engineering solution that almost anyone could fabricate without any engineering skills, and very little in the way of tools, just the basics, I have been around Vincents for a good few years, and yet this solution to a problem is totally new to me, very inventive, but also very simple, I like it.

 

[erik]

I have a steel rod with two grooves sitting two o-rings in it. This has the right friction inside the crankshaft. Erik

 

[Graham Smith]

I made my own, but the Spares Company sell one off the shelf.

Like Peter though, I like Robert’s solution.

 

[Comet Rider]

I made my own, but the Spares Company sell one off the shelf.

Like Peter though, I like Robert’s solution.

View attachment 54538

I'm amazed that the VOCSC adds an additional £2.65 to put the two items in the same bag.

I made my own to a similar idea as Robert, but with a tapered plug in the end of the tube, and a little tommy bar on the outside to lock it in place

 

[litnman]

Don't recall who made these but sure are handy for timing with a timing light. Had to add a few bumps of silver solder to tighten up in the crank. No mess with oil since it has a seal in it.

 

[timetraveller]

ClevTrev made them. I agree, very useful.

 

[gmax137]

I had an email exchange with Bill Easter who directed me to François Grossett -- he makes them (or something similar). I understand this allows for adjusting ignition timing with the engine running.

 

[bmetcalf]

Not really, it does allow you to use a timing light to see the spark advance degrees from idle up to full advance. With a Lucas mag, you still have to play with the ATD taper.

 

[BigEd]

The new style BT-H Magneto has slotted fixing holes so that you can make timing adjustments by slackening the three fixing bolts. When first installing the magneto set it in the middle of the slots and then set the engine to get your target firing point. You will then be able to try turning the body either clockwise or anti-clockwise to see if more or less advance improves things. This is useful for static adjustment and also dynamic adjustment using the tool in post #15. I have used the tool successfully a few times. If you find that you run out of adjustment with the slots you can set the magneto back to the middle and move the timing gear a little on the taper and repeat the operation. The BT-H magneto has an "O" ring that seems OK to keep a seal between the magneto and crankcase when the bolts are just cracked enough to allow the body to be turned.
Some of the magneto replacement units used to fit electronic ignition systems, e.g. Boyer, Pazon, etc might also have slots.

 

[timetraveller]

And of course, the distributer used with coil ignition can also be rotated. Easiest of the lot and a bigger spark at low revs,