TR2/3/3A Ignition Run-On

Carter low pressure electric fuel pump, Pertronix electronic ignition, carbs seem to be properly set, idle at 800. When I turn the ignition off, the engine keeps running a little, bumpity-bumpity-bumpity - brrrr-thud. If I disconnect the battery, same thing. If I turn the ignition back on while this is happening, it fires back up completely.

I think this is called "run-on." How do I stop it?

Also a general question about Forum searches. If I type in run on, it gives me "run, on" and rejects the search request because it will return too many items. Is there a way to string words together? Do you use quotes? Some other method?

Thanks.

Put you foot on the brake, leave it in gear and dump the clutch as you turn off the ignition.

Mine will do it sometimes as I really can't get it to idle much below about 900 rpm with the cam and all else that I did to the engine. Therefore, I just got into the habit of dumping the clutch. If timed right, you can't even tell it was done.

Also, I pretty sure the search engine will accept quotes and + signs between the words.

If you can get the idle down to the specified 500 rpm, the runon will likely disappear. I can't, though, so I do the same as Art. With a little practice, it becomes habit and you can do it so smoothly you won't know if the engine wanted to runon or not. But be sure to keep your other foot on the brake, just in case it tries to go another turn.

I had the same problem for a while. Try running a tank or two of high octane fuel. This should run hot enough to burn out the carbon deposits that are causing your run on. If the problem comes back on regular, make the switch to premium. Worked for me.

My 1960 TR3a has been running on since I bought it 6 months ago I have tried cooler plugs, lower idle,moving distributor?? both ways,high test gas, even driving at
4000 rpm for 30 minutes (to remove carbon) no change.The car runs extremely well plenty of power next move remove head and check for hot spots ? meanwhile
stalling out works for me
Dave.