I have a 47 pont I just switched to 12v and I am having a problem with voltage drop to the coil when cranking. It drops to around 9v when starter pedel it engaged. Any help?
If you switched to a 12v coil, you need one power feed to coil thru a ballast resistor. A second feed goes from the starter solenoid to the coil to feed it 12v while starter is cranking. Coil, when engine is running fed thru ballast resistor, wont have 12vs.
Are you still running the stock 6V starter with the foot pedal start switch? If so, you have nowhere to put a 12V byp*** wire to the coil. A starter ****on to shoot 12V to the coil on start is one way around the problem.
It could be a problem in the starter, wiring or the battery. Connect your voltmeter across the battery and try the starter. The battery voltage shouldn't drop below 10V, if it does your battery may be defective. If that checks out okay connect the voltmeter across the terminals on the solenoid and try the starter again. There should be well under a volt across the solenoid when cranking the starter. If there's a larger drop the solenoid needs replacing. If the solenoid checks out okay then it's time to pull the starter and look at the brushes and bushings to make sure they are all properly installed and working. If all is okay there it might be a bad winding in the starter or a problem with the commutator on the armature.
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