Hitchcocks Forum

Hi all.
I'm after some advice please.
I have a 1960 Constellation twin carb model, and have recently been having some misfire issues. I had the condenser in the mag fail a couple of months ago, and a brightspark easy cap was fitted. Been putting some miles on it this week, and all seemed to be fine. New plugs fitted, carb fuel filter and main jets checked and cleaned, but after 20 miles today, mostly 50 - 60 mph, it developed a misfire. It's not losing power completely, but "hesitant" both when accelerating and holding a constant speed. It's been suggested to me that it could be carb icing (it was a bit brass monkeys today, and a fair bit of the ride was quite high up). What do you guys think?
Many thanks
Rob

Footnote...I Did notice the right hand side plug cap wasn't quite as tight a fit as the other side. Could this loose fit be part of the problem?

Hi Rob, When the Brightspark Capacitor was fitted was the armature stripped and the old capacitor disconnected?. If not then the old one may be getting leaky and reducing the spark voltage.

Hi Dennis. Yes the feed wires to the old condenser were disconnected and isolated.

Didn't fit iridium plugs by any chance?

Hi Norm. Standard NGK plugs as always. I am going to try some spare ones just in case I have a dud, but I'm not holding my breath.

Rob you can get a dud plug, I fitted irridiums in my Inter and it was unrideable, put the old plugs back in and they are still in it