Triumph Repair: 72 Spitfire Mx IV. Weber Carb - Cust out when warm, zenith stromberg, weber 32

Question
Hi Jim,
Thanks for the help you have given me to date.
I swapped the carb from the Zenith/Stromberg to a Weber 32/36 DGV with a water choke.
Everything works great (at first.) The chkke appears to engage and disengage when cold & warm respectively.
However, when starting from cold, it runs excellently until I've driven about 1/2 - 1 mile.  Then, it cuts out and won't start again until the engine is cold again.
Any suggestions?
Thanks,
Gavin.

Answer
Gavin,

That sounds like either a) the choke isn't disengaging completely (but you've ruled that out?) or b) there's an electrical connection that's bad/broken.. it makes contact when cold but breaks apart when it's warmed up.  

That sometimes happens with the ignition coil.

A good test would be to pull a spark plug lead and fit it to a "spare" sparkplug and ground the body of the sparkplug when the engine has died.  Have a friend turn over the engine and see if there's spark.  If not, time to go through the ignition system.

If there is spark then it's still something in the fuel system.

Cheers,

Jim