A 10 K2F manual advance

[mike.loehr]

Thanks to all for the information.Now on to the question of what doesent make sense to me.Pulled right side cover and put my degree wheel on the crankshaft end along with a piston stop pin in the spark plug hole on compression stroke.Determined timing set at 34 degrees BTDC full advance.(Lever set full slack).From what I have read the notch in the cam ring limits the timing retard movement to 15 degrees,so 15 degrees minus 34 degrees is 19 degrees advance fully retarded on start up which kicks like a mule.Is this correct or am I missing the point altogether.,Is this the normal advance?Can you modify the notch for less advance or do I have a different problem.

[groily]

Not quite as you describe Mike.
There are usually about 19% of retard on the MAGNETO, which would be 38° on the crank. Give or take.
The notch which controls the arc of the camring is about 11mm long usually and the ring should use all of it.
If it isn't moving 'full arc' then the cable is somehow limiting it owing to poor adjustment or there is an obstruction.

If you start enlarging the notch to try to increase the RETARD, you'll find the plunger on the cable may disengage, so that's a bad idea. You don't want more advance than you've set the timing at. Shrinking the notch is  tricky game, but shouldn't be necessary unless your notch is very worn.
Most A10s will start OK with about half the retard used. Needs a firm swing not a tentative poke on the kickstart, but most will also start fully advanced if they have to. The less retard used, the stronger the spark as mags work best at full advance.
(I sent a PM (private message) the other day with a bit more info which I don't think you might have spotted.)

[Swarfcut]

 My guess is that the basic timing is incorrect, maybe set up at full advance with a seized cam. The relationship of the magneto drive gear on the shaft taper needs to be set up by the book, once the magneto advance mechanism has been sorted and there should be no need to modify an unmolested cam ring. Best to treat magnetos with respect, hammering magneto shafts is only for the rich, so get an extractor for the drive gear.

 Swarfy.

[berger]

bill is right don't mess your ring i did i ground a bit out and plungy thing got jammed i had to drop a spacer down the hole in the mag to stop it doing this.

[Triton Thrasher]

It’s a bit mad to think there’s a need to extend the range of the manual timing control.