My car suffers from overrun i.e. keeps runnig for 5 seconds or so after I turn it off. I know bugger all about engines so write slowly so I understand in laymans terms, but it's a 1916 (94s) with Kads. Any comments will help, Bill

Generally this is caused by heat. The motor gets hot and will continue to run after the ignition is switched off because the heat in the combustion chamber is igniting the fuel.

Check to see whether you have a fuel cut-off solenoid installed on the carby.

Maybe you can alter the timing to keep the motor a bit cooler (retard slightly).

Different quality fuels make a difference also.

Thanks... I'll try it out.

kads dont have idling solenoids thats half the problem!!!
it happens with my bros motor aswell best cure is give it a good squirt before turning it off!!
cheers
rhys
p.s. or take of the heads and clean the carbon off!

easier way to remove the carbon is to run redex through regularly..ish.
see the previous thread on 'engine run on' probs
put the car in first and release the clutch as you switch off the ignition and squirt the go fast pedal if you can juggle and sing at the same time as this you're doing well

My engine has done this for 10 years - no carbon on the heads last time I looked. But it's a pain in the arse. Kad's dont' have idle cut solenoids to block idle fuel supply when the ignition is turned off. My fix is to 'stall' the engine against the clutch at the same time I turn off the key... works for me!

I am going to disagree here and hopefully not start a fight

I have run a Progressive Weber and twin IDF Webers and neither of these have shut off.
I had run on with the progressive BUT tuned it out.

I have found run on to be mainly caused by
1) overly rich idle mixture
2) too advanced
3) idle set to high

The main people i find that suffer run on is people who run kadrons. I have also heard kadrons run rich.
I have never run kadrons
I would say the problem could be related to kadrons. I dont ever hear from people with Dels or IDF's or IDA's suffering this problem.

Had this problem with a progressive weber. Went away when I adjusted the valves.

Thanks everyone. I've had people tell me it mostly happens with kadrons. I'll try some of those things mentioned. The idle is normal but it may be running rich. Maybe I should turn the car off 5 minutes before I get to my destination... or get used to stalling it. I'm a terrible juggler but I sing alright