V50 Monza Advance springs

Just been preparing to reinstall the ignition gubbins and install new dyna s on my Monza. When inspecting the advance assembly noticed that the springs are uneven - one thicker than the other. The thicker one seems sloppy and does not offer much tension and the thinner spring has nice tension. Assumed someone had put in the wrong spring but when new springs came they are the same -odd. Has anyone any insight as to why this is?



Only my guess, but sounds like the different springs are a kind of dual-rate setup. The light spring controls the initial advance and then the heavier one will come under tension and take over.

Hi Martin, the V50III and Monza do indeed use two different advance springs. One has a length of 0.696" has 9 coils and a wire diameter of 0.029". The other has a length of 0.735" has 7 coils and a wire diameter of 0.039". The correct part number for the set is 19 71 98 20. It sounds like your new springs could be correct. I suggest you check them then fit them. All this info came from Guzziology so thank Dave Richardson.

Both springs work in different rev range, doing slightly different job - that’s why. Everything is correct in your case. But it doesn’t mean you’ll be successful in setting both ignition points, as we all know:)

What he said, yes the springs are different and one is “sloppy” so you get a step in the advance curve, initially steep then flattening off.

Thanks all

That clears that up then. All makes sense. I am moving to a Dyna s ignition so have that challenge to come. I think I had my points pretty good previously but it does seem like a very fluid exercise getting points gaps and timing synchronised with one adjustment affecting the other.

Thanks again