I've recently bought a late Series V with original 1725 engine and standard twin Strombergs.
The car is in lovely condition but has a really lumpy tickover.
Following some good reviews on the forum I decided to fit a Petronix electronic ignition and Flamethrower coil. Unfortunately when I put the distributor cap back on I trapped the wires. The resulting short circuit caused a cloud of smoke and melted the wiring loom. On closer inspection it appears that the only wires damaged are the White wires that run from the coil to the rev counter and from the rev counter to the ignition switch.
I've replaced these wires and the car now runs (still lumpy) but is really difficult to start with the key. With the ignition on I can start the car easily from inside the engine bay (with the button on the passenger side inner wing). Using the key the engine just turns and turns, however if you let it turn a couple of times and then turn the key back to the "normal" position and hit the accelerator at just the right time it will "catch" and fire up. Have I damaged the ignition switch? Is it worth replacing, or does the fact that it starts from the engine bay mean the problem is somewhere else?
Also, if you turn the ignition key too far when turning off the engine it will still run in the fully anti-clockwise position (the position where the radio works) Is this normal?

Any advice gratefully received.

It sounds as if the ign sw is damaged, and is no longer supplying the coil when you turn to 'start'. You could check this by turning the wipers on and seeing if they stop. And the engine should not run when you turn the key left to 'accessories'.
A lumpy tickover is not unusual and if you have fixed the spark system, it's probably the set-up of the carbs. You should aim for a tickover speed of 1000rpm.
The simplest checks are:
1. Balance. Remove the filters. Run the engine at idle and listen to each carb's hiss via a length of rubber or plastic pipe - servo air pipe is good. Then rev up the engine and watch the pistons rise. The louder hiss and the higher piston are the carb doing more work. If the results conflict, the throttle stop on the rear carb may be screwed in too far. Note that there will probably be wear in the linkage. This doesn't matter too much as the rear carb always 'hangs' off the front.
2. Mixture. At idle, raise each carb's piston lifter SLIGHTLY. With the carbs balanced, each should have the same effect, which is that the engine should briefly accelerate, then drop back and probably run slow.
If the above doesn't improve matters, then you have to start checking diaphragms, needle position, jet height, float height and manifold air leaks. Also leaks from the breather valve on the manifold (block it to check if in doubt).

Chris

Thanks for the reply.
I think I'll change the ignition switch (if they're still available, I haven't looked yet.)
I've already played with the carbs, I bought a Gunson Carb Balancer and I think I've got them both pretty close. I've also bought a Gunson Colourtune but I'm having a few problems with that because the idle is so lumpy.
I think I've got the timing wrong (I forgot to disconnect the vacuum advance!) I'll sort the timing out and change the ign switch and have another fiddle with the carbs.
Also my new stainless steel exhaust sounds like it's blowing, I guess that's not helping either.
I'll let you know how I get on.

It does sound like the ignition switch is damaged, but replacements are available at reasonable prices. Trapping the distributor wire should not have caused the switch/wiring melt problem though as the points create an effective short circuit anyway each time they close, and the coil/ballsst is still in circuit. So thats a bit of a puzzle.

I would advise you to inspect your wiring loom carefully and isolate/replace any burnt wires. You do not want a short to occur and cause a fire or accident.

Well that didn't work.
I've reset the timing and I've just replaced the ignition switch, distributor cap and rotor arm. I've removed the black tape from the wiring loom, from the engine bay back to the ignition switch. The only wires damaged were the white wire from the coil to rev counter, and rev counter to ignition switch. I've replaced the damaged wire but still have the same problem starting. I've got the hang of starting it by turning the engine over a couple of times and hitting the accelerator as I release the ignition key (I guess this is the same as bump starting). It starts easily from the button in the engine bay.
Any ideas?
I'll be heading down to Beaulieu tomorrow, if anyone wants to stop by and have a look please do. The car is an Oxford Blue Series V Sport (the one on my avatar). We'll also be taking a black Nissan X-Trail and 2 very excited children.
Fingers crossed for some sunny weather!

I think the only useful thing I can say on the eve of the 2008 National is 'See you at Beaulieu!' (Pale blue SV KEA 419E - as per the frontespiece of the Alpine Guide).