I spotted an old thread about using and aftermarket Fiat 500 ignition by DD. Looks cool. One question though.. Are those backplates you have home made? look prety precise to me. I reckon I could knock something up stitch drilling and filing but could it be made from acrylic?
The dwell angle for the original points is around 180 degrees. The points are closed for about 1/2 of a crank rotation.
The Netronics optical pickup can easily be designed to get about the same dwell. See:
Per their documentation, the Accent ignition is also designed to get an appropriate dwell angle.
Some of the magnetic systems provide much higher dwell angles. The coil is charged for more degrees of rotation, which is great for a good spark but taxes the battery+alternator more.
The twins have a barely adequate alternator & tiny battery. So some of those magnetic systems may overtax the battery+alternator.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more
hi dax, sorry i missed this post somehow. my mate round the corner made half a dozen backplates for me from some solid round brass bar. drilled them, did the slots, then pared them off. i suppose you could use acrylic, but it would have to be fairly thick, due to the 2 tiny holes - m2.5 - that hold the pickup on have to be threaded. probably a lot easier to machine brass, as acrylic has a tendency to crack when you file it, unless you're VERY careful. i'm sure i sent you the dimensions for the backplate a couple of years ago. have a look through your old pm's. if it isn't there, give me a shout and i'll measure one up for you
cheers, dd.
GTS250 road registered. TS250 engine, Ramair frame.
GT250 big bang road registered. Both pistons fire the same time. USD forks.
GT285 road registered. Overbored - 58mm and TS125 +2 pistons fitted.
GT10 road registered. '65 T10 engine, GT250 frame.
dollydog wrote: ↑Wed Jun 30, 2021 5:42 am
hi dax, sorry i missed this post somehow. my mate round the corner made half a dozen backplates for me from some solid round brass bar. drilled them, did the slots, then pared them off. i suppose you could use acrylic, but it would have to be fairly thick, due to the 2 tiny holes - m2.5 - that hold the pickup on have to be threaded. probably a lot easier to machine brass, as acrylic has a tendency to crack when you file it, unless you're VERY careful. i'm sure i sent you the dimensions for the backplate a couple of years ago. have a look through your old pm's. if it isn't there, give me a shout and i'll measure one up for you
cheers, dd.
Hi DD
The dims are in the original post/thread I pinched the photo from, so no problem.
