02-03-2020, 01:15 AM
(02-02-2020, 11:52 PM)m in sc_imp Wrote: wasted spark is correct. as said above, each coil is fired every 360 degrees of crank rotation. this means it fires near btdc on the combustion stroke, the next time that cyl fires is near top dead center of the exhaust stroke. in effect, the crankshaft itself is the distributor. so, the coil will fire cyl 1 and 4 at same time, and 2 and 3 at same time. however, cyl 1 may be on the power stroke, cyl 4 may be at the exhaust stroke.
the electronic ignition on the rd350 I posted is actually one for a japanese 4cyl.
now, another one forgot is overhead cam twins, such as cb350, 450, xs650, etc. these have points off the cam shaft in the head.
what I think your missing is that theres multiple coils, and that they are simply triggered at the motor, just in a more analog fashion. in lots of ways, more similar to modern car engines with coil on plug setups triggered by a crank sensor. hope this helps
Yes, as did my CB160, CL160, CL350, SL350 and CB360.
Sportsters ran points off the camshaft before a cam position sensor replaced points in the "nosecone".
Some riders got confused with setting timing, since Sportster cams rotate CCW, although the crank is CW.