Running On

Hello,
my SIII SWB petrol once warmed up and been run for a while will once I turn it off and remove the key will keep running for sometimes up to 10 secs. It starts first turn when cold but once warm will take many attempts to start.
What can I start looking at to rectify this.
Any help gratefully received,
tom

Easiest place to start is the spark plugs, are they the right grade, have they carboned up. Next is the ignition timing.

The usual cause of running on or pre-ignition is carbon deposits in the combustion chamber getting hot or the spark plug getting too hot and igniting the fuel instead of the ignition spark.

never mind how it runs with key or not where the fook is my screen

running on in a series is usually either ign timing out or mixture too rich.. in your case i'd try yer mixture first..i;e is yer choke stickin on

or overheating?

Poor starting when hot is full evaporation from the carb / fuel pipe, as its routed around the hot bits of the cylinder head. Usually if you restart fairly soon its ok, but more than about 5 mins or more it can take a bit of cranking. You can check if this is the problem by manually working the fuel pump when it normally would happen, this should replenish the float chamber and start normally.

how does that explain the running on??
and thats only one cause of not starting when hot

hi

i had the same prob and adjusted the fuel mix ,it was running a little rich and is now fine. and its the easiest to "put back" if it dont do the job but mark the origainal setting first so you can put it back there if you need to and turn the screw as your looking at in in a clockwise direction

Running on usually heat related. Either mixture too weak on ign retarded. Also associated with the popping in the exhaust on overrun. Check points gap / pitting. Replace if required. Set manual timing at 3deg btdc with 12v bulb between points spring and earth. Should be a good place to start with the ignition side if it. 3deg btdc is good for UK octane fuel. You can play with the mixure after that. Worn butterfly spindle on zeneth also causes weak mix.