#20 PostAuthor: warren3200gt » Sat Oct 03, 2015 9:52 pm
Points worked fine for years and years, setting the dwell angle is the way to go. I had fireworks coming from the 1 & 4 points on the 650. This obvisously caused a bad misfire and hard starting. After faffing with new points and condensor it was no better. After mucho reading up on various forums to find the cause it pointed towards the dwell angle. In essence, If the dwelll angle is too small the points will remain closed for too long. This has the effect of trying to over charge the primary coil windings. The excess power has to go someplace and arcs back across the points. The 650's gap should be .3 to .4 according to the manuals and the dwell should be 185 to 195 deg. With points set to .35 the dwell was only about 130 deg and nothing I did could keep the gap correct and increase the dwell. I decided to set them by dwell and ignore the gap. Once set I adjusted the timing and checked the gap, it measured.55 which is very wide but the misfire had disappeared and it ran smoothly with no misfire. So it would appear it's a case of a gap is a gap regardless of size and its the opening and closing that really matters?
could someone confirm or correct my findings

PUM 488 June 2026
76 Z900A4, 77 Z650B1, 77 KZ650B1, 77 Z1000A1, 82 Z1000J2, ZRX1100R.