My engine overrunns. Turn it off and it keeps spluttering.?

Here's a quick fix I learned from some old-timers with my antique truck restoration. When the carbon builds up on the top of the pistons and the combustion chambers, it will get hot and be hot enough to keep the engine running even after the ignition is turned off, its called "dieseling."

To fix it, go buy a bottle of Marvel Mystery Oil, and with the engine warmed up and running at an idle, slowly pour it down the carb. The engine will bog down and sputter, the stop pouring for a minute until the idle speed comes back up, and repeat 5 or 6 times, then pour enough of the Marvel Mystery Oil into the carb SLOWLY so that the engine stalls out. Let your vehicle sit for about an hour, then go fire it up and drive it around until it stops smoking, it will smoke horribly for a mile or two but it will dissolve all of the carbon and get it out of your engine.

If that doesn't work, take out all of your spark plugs and pour a mixture of Marvel Mystery Oil, Diesel Fuel, and Kerosene into each cylinder, let it soak overnight, and then drain out each cylinder, replace the spark plugs and go drive it around, that will also dissolve the carbon build up.

Carbon builds up in the combustion chambers---the pistons will get a little extra run on called 'dieseling'----comes from bad timing and not burning all the gasoline that gets sprayed into the combustion chamber--it continues to run and shake as the carbon glows hot enough to cause that condition. You need a shop to completely check the car out--you can't do it and you should NOT try doing anything silly--you could ruin the motor. Good luck.

if the timing is out, the mixture is too weak,there is an air leak ,the tickover is too fast or there is a lot of carbon in the head(it glows red hot and ignites whatever vapours are left even when ignition is off) then all of these will cause the engine to run on

check the timing for a start mate

It is either out of time or idling too fast.

timing defo