1991 Merc 4 suddenly decided not to start - has been very reliable up till now. Carb / fuel system is fine (checked and re-built carb). <br /><br />With spark plug removed, the spark is orange, not blue. Changed the plug and that didn't help - even tried changing the lead for an old car one and no difference. <br /><br />The stator resitance is 82 ohms and trigger coil is 92 ohms so I think both of these are fine. I don't have the Merc tester so can't test the coil i/p voltage (was getting unpredictable results however there is at least something there).<br /><br />My question - does this sould like a coil problem or could it be the CD unit? Is there any way of verifying which one (if any) is faulty? or does anyone have any other suggestions? <br /><br />(Note - stop switch is fine - in fact I disconencted it so that's not the problem). <br /><br />Thanks. <br />Al.
