Runaway 8N engine

[Priest]

1948 8N front mount 12V conversion. I was out getting some good seat time working a box blade when I hear squeals come and go with no change to engine power, probably fan belt. anyway the engine RPM jumps up like I'm trying to run from the cops, with no throttle response when I move the handle all the way left, then I try the key OFF, still engine is racing so I lift the Box blade and head to the barn. I had to turn the fuel shutoff valve to kill the engine. any advice as to where I should start diagnosis?

 

[Den N Ms]

Priest.Any advice as to where I should start diagnosis?
Yeh, you had better go out and disconnect a battery cable before it melts some wires,burns points or coil up or catches fire.

 

[HCooke]

Run away rpms - check throtle and gov linkage. Won't
shut off with the key - wiring.

 

[Priest]

no problem with the Electric.

The connecting rod between the carburetor and governor came off. So I'm back to more seat time.
:lol:

 

[souNdguy]

if it won't shutoff with the key, you MOST CERTAINTLY have an electrical issue!!!

soundguy

 

[old]

If it would not shut off with the key you still have a problem since gov/carb linkage have nothing to do with engine shut down so you need to double check your ignition system also

 

[Priest]

OK, so I'll admit to an electrical issue if it doesn't shut off with the Key.
(but who among us have NO issues)
tomorrow I'll try to start it with the key in the Off position.
Any other ideas as to what to check? :?:

 

[Den N Ms]

Does it have a 12 volt alternator on it.If so you need a diode or a idiot light hooked up from the ignition switch to the tickle wire to the alternator.

 

[souNdguy]

ditto what den said about alternator / ignition isolation