[ROVERNET - UK] Mixture problems-resolved, sort of...

[Steven Dibdin]

Hi All,

Thank you for all your responses. I have tried a number of solutions and the results are:

New flame thrower coil with points give the best idle and performance. This must be the first case of Lucas products beating modern electronics. I will call petronix to discuss later on. When left to idle plugs would soot up from incomplete combustion after about 90 secs.

The spark at idle with the petronix unit in place was yellow and quite weak (0.030" gap on plugs as per instructions).

With the points in place it was much stronger and would jump a much bigger gap. Engine idled for 5 minutes with out a change in idle speed or smoothness. 

I Checked plugs after and they were a nice biscuit colour suggesting correct mixture and full combustion. This is with the mixture set as per the manual. Lift pins 1 mm engine note rises then drops on each carb. 

So it would seem the mixture was a red herring, it was down to a weak spark at idle causing poor ignition and rough running. Strange that at higher RPMs the problem ceased. I still wonder if it was down to voltage difference at idle affecting the hall sensor.

Cheers,

Steven