Ignition timing advancing with revs?

[Jackomad5]

Hi, please help!

Currently trying to get my timing sorted on my LML malossi 166, ignition system is LML (separate coil and CDI) (fixed timing)

Timing is strobed at the 3000 ish rpm at 17/18

Thing is when I rev it high and the pipe kicks in the timing waaaay advances to well above 20. Is this normal? Surely this can’t be going on inside the engine.

I will add that I have melted a piston on this previously, however at the time I put that down to the timing simply being set to high to begin with, of course I’m now starting to question if this was the issue.

Appreciate any response! Cheers

[eibargum]

Iam relatively new to Vespas Jack so take all I say with a pinch of salt, I recently fitted a Polini 210 top end on my "apart from SIP road 2" standard PX, I strobed it to 19 degrees and noticed mine advances when revving it.

[Jackomad5]

Well atleast I’m not the only one eibar! I’ve known them to advance slightly when stobed but never to this degree

[Jackomad5]

Anyone any ideas?

[Adam_Winstone]

I had it recently and had to rescue it with a change of pickup and alignment.

[Jackomad5]

Adam, good shout but thing is I’ve swapped stator, cdi and coil all to no avail

[mick1]

loose magnets in flywheel ?

worn bearing (causing crank/flywheel movement) ?

[Jackomad5]

Cheers mick, cant see it. Motor has had new bearings and crank recently.
Sounds then as if this is absolutely something that shouldn’t be happening? As opposed to maybe an LML thing (might just convert to Ducati) Or maybe I’m getting a false reading somehow Aargh

[Jackomad5]

For anybody interested it turned out that it was the pickup or pickup height as Adam mentioned.

Both the LML stators I had gave me the problem. Tried a vespa stator, problem solved. Changed pickup on my LML stator and raised it to match the vespa stator and all is good!

Vespa wins