Brief Description: Hunting for the engine miss ...
Spent the morning hunting the engine miss when running on 1 mag. Today's mystery - the difference in colour of the fuel drained from the carbi bowl and from the gascolator and fuel tank. Fuel from the tank and gascolator still looks at is should for RON 98 Mogas - but the fuel in the carbi bowl is orange. This has been the same each time I test the fuel before the first start up for each day. After the engine has been run, the fuel in the carbi bowl is the right colour ..........
Pulled all the plugs and re-gapped them. They were all around the wide end of the range (26 to 27 thou) so I gapped them all at the narrow end of the scale at 22 thou. All were good colour though the LH plug in cylinder #5 looked a little oily. Replaced that plug but there was no change in the engine missing. That plug is powered by the right mag.
Tested the mags with Peter T - and discovered when the ignition switch is in the R position the right mag is shorted leaving just the left mag is running. And when the switch is in the L position the left mag is shorted leaving just the right mag running. I might reverse this as it feels backwards to me.
The engine miss is when the switch is in the R position (ie running on just the left mag). Pity the possible weak lead/plug runs off the right mag!
More thinking required before the next diagnosing session ....
