The rebuild of my 1976 V700 has stalled a few times for a variety of reasons but I am currently a little worried by the ignition timing. The book value is 10 degrees before TDC on the left cylinder however, if I set this, the right cylinder is only 5 degrees before TDC. At present, I have 'split the difference at 14 before and 9 before but not too comfortable about this.
Anybody have any advice ?
Hi Chris, The figure you have of 10 degrees btdc on the lh cylinder is correct. How are you getting your figure for the rh cylinder? The marks on the generator pulley only work for the left side. As there is only one set of points and everything is geared together, I can’t see how settings would be wrong across the two cylinders (unless that’s how Guzzi wanted it).
Me again. Just a thought. Are you sure you’re timing the left cylinder with the left plug lead? The distributor cap is marked with “1” and “2”. The left cylinder is “2” and it’s the lower HT lead - the one closest to the rh cylinder. No1 goes to the right meaning they cross over. It might be worth putting the rotor arm on to see which plug it’s firing.
Agree with John - I have also tried to time mine with the pulley bolted in the wrong position. It would run but not well.
I have found that if I set the static timing correctly I don’t get to the full advance position when I check with a strobe, so I tend to make sure I get full advance and let the static timing go where it will. That is a function of the distributor advance mechanism and I suppose I should have a look at it some time, but it seems to run well so I am leaving alone.
Guy W told me that he’d once checked both left and right on his loop with a strobe and found a slight difference, which must be due to the cam shape in the distributor. I tried mine but was spot-on between the 2 sides.
Guy never checks em with a strobe Ian, yer must ave imagined it mon ami…hes gone back to his dads method cos he realised he’d got far too anal about it all…
His Dad used to…on tickover…on any vehicle…advance the distributor…until he’d got the highest tickover…then back the dizzy off (retard)…until the revs dropped a few hundred rpm…then ride it…if it pinks…back it off a little bit more…if it doesnt pink…leave it alone…
That is the way I used to time all my old cars and bikes, but since riding Guzzis and reading all the stuff on forums, I got all anal about doing it all “proper.” Time to go back to the suck it and see method, I think! It never caused any problems on Moggies!