140 - 42 jets took shims out(2) but have tried different jets and shim combinations don't make any difference. Have checked diaphragms several times. It sometimes only starts on one cylinder for perhaps 1-2 seconds sometimes and when you rev it up at standstill does not feel as crisp as it should.plugs are a nice color. It does not use water . I run bikes on common land in my younger days with no silencers or air filters and they ran fine without touching jets in carbs. My mechanic friend thinks it's electrical as well as myself. There are no CDI boxes for sale in UK at moment and to get one from usa is big money especially if it's not that playing up.