Ignition advance problem.

I have after 18 months of dismantling, cleaning, painting etc, started the Guzzi up for the first time yesterday, and would like to thank everybody who has offered advice to me for their help in getting me to this stage. It sounds very nice with the Lanfranconis on although I’m not sure that the neigbours agree . So it was down to fine tuning, and I found that I could not get the full range of advance on the ignition timing, i.e. if I set the timing at tickover to the correct marks I could not get the advanced timing marks to appear despite revving past 6000 rpm. I have two different slightly different looking (rated?) springs on the bobweights, and the bob weights are free. So apart from buying and fitting two new springs, does anybody have any ideas as to what if anything else could be the problem, or do they “all do that?”
ReggieV2013-04-04 10:59:56

But isn’t the timing already into it’s advance curve at idle?I set the static timing using the first mark above TDC and then go for full advance - otherwise you can be as much as 5degrees out.

According to Guzziology on most of the big twins the timing has already begun to advance at idle speed and using these marks can leave the timing 5 degrees retarded at full advance.

The recommended method is to use the static marks to get the engine running then set it accurately using the full advance timing marks.

On my MK111 I set the timing at static when on points and left it at that.
It revved to ,8250 easily with more when well warm so that did for me.
On Lucas Rita it is set at 6,000+ as per the instructions.
Revs the same.

OK, thanks for the info. I will time to full advance and leave it at that.

What Ian said. Stopped bothering with strobe guns when I discovered how much it wanders about anyway due to the play in the drive gears etc., I set it so points open at TDC when crank turned by hand, that’s it. Then go by ‘feel’, if it feels rough / vibrates when you ride it, it’s too advanced, so back it off a gnats (rotate timing body clockwise a gnat’s whisker); repeat as necessary.

Appendix ~ yes the two bob weight springs are different, so there’s two different slopes: NOTE r.p.m. is of BREAKER CAM NOT CRANKSHAFT so 500 r.p.m. is actually 1,000 r.p.m. of crank. So actually no shouldn’t start to auto-advance at that point yet, despite what Guzziology say, unless they’ve misread the r.p.m. as being crankshaft speed, which it isn’t. HTH