Starter trouble

[Jyrki]

Anyone help me please, I'm desperate! The starter on my 46 Roadie is giving me hard time. The symptoms are like a bad starter drive: many times when I start, I just hear the starter rev up high, sometimes it may crank the engine a couple of turns, and then slip. Sometimes it cranks fine. I thought the culprit was a bad starter drive. I got a new (yes, NEW) starter drive from eBay and installed it yesterday, to no avail.

I am using the original 6-volt starter with 12 volts (I never tried it with 6 volts). During the initial build-up, I replaced two out of three bushings (don't remember which ones) and brushes, and trued the contact surfaces inside the solenoid. I also adjusted the pinion travel to specs by adjusting the solenoid plunger stud.

During the initial start-ups, the starter cranked just fine, over and over. Then, all of a sudden, it began to miss, and the problem seems to get worse. There is no way to adjust the contact pattern between the pinion and flywheel teeth, because of the starter mounting system.

The starter acts like the solenoid was closing the main contacts too early. But like I said, it has been adjusted to specs. PLEASE HELP!!!

[Charles2]

You may want to check your ring gear. If it is missing some teeth then it could be causing the symptoms you describe (if I understand them correctly). This is an easy check; just remove the sheet metal flywheel cover and rotate the engine while looking at the teeth. I hope it isn't the ring gear. That is a lot more work than R&R'ing the starter. Good luck!

[Guest 53and61]

Operating the 6V starter on 12V should be OK, because maximum current through the very low-resistance starter motor at stall will be limited by wiring resistance and the battery's internal series resistance, which will be significantly higher for a 12V battery than a 6V one. But this limiting doesn't apply to the solenoid windings, except that they are protected by the 6V starter pulling the system voltage way down during cranking. I'm not sure you can depend on this protection and wonder if you've burned out the hold-in winding on the solenoid. I'd expect the solenoid to chatter in and out in this scenario, but maybe not. Probably wishful thinking on my part, as your symptoms seem classic for missing teeth on the flywheel as pointed out by Charles, a more miserable problem indeed. Good luck, and please let us know the outcome.

[Jyrki]

Thanks for the feedback. All of it makes sense to me. When I built the car 390 miles ago, none of the ring gear teeth were missing. Of course, there could be now. Unfortunately it is not very easy to unbolt the cover to check the teeth, as I have modified the rear motor mount due to my Super T-10 gearbox. I will try to get another solenoid on loan, and see if that would help. Maybe I should have used a ballast resistor to the solenoid to cut down the voltage/current running trough it. Anyway, thanks a lot for good advice!

[Patrick W. Brooks]

Hello: Have read your post with great interest. It is doubtful the fly wheel is missing teeth, although checking its condition is a good idea. Even if some of the teeth are damaged, which I have encountered, it would be very unusual for them to be damaged so they would cause the symptoms you describe. I would have further suggestions. First, take a push button connected to the positive side of the battery and hot lead to the selenoid to jump around the starter switch hung on the carb. A hot wire goes from the ignition to the starter switch which hangs on the carb and is engaged when you push the accelerator to the floor. This shoots current to the starter and selenoid. It might not be functioning correctly or have a loose wire, etc. Jumping around it is the easiest way to check. If the starter acts the same the problem is not associated with the starter switch. Second, when I convert to a 12 volt starter I always use a selenoid designed for a 12 volt system and not 6 volt. This could be your problem for some reason. I understand 6 volt wiring is actually heavier than 12 volt, which is why a new wiring harness is not required, etc. However, since I have not had the problem you describe you might try a selenoid designed for a 12 volt system and see what happens. I was told by the owner of a starter/generator shop, many years ago, to use a 12 volt selenoid and have done so. I have not had any problems on the several 6 to 12 volt conversions I haved done. Third, the starter might have gotton hot and the internal ground might be bad and this will cause the starter to fail after short use. I know from experience as this happened to me on a 1949 Super convertible. In any event, hope these ideas are of some help. Post your final conclusion for those of us who have read this post. Solutions to such problems are always interesting. Patrick W. Brooks

[Jyrki]

I was able to locate a guy with a 12V solenoid, from a 1953 Buick I think. Once I get it, I will see if it fits, and give it a try.

[Jyrki]

Okay folks, thank you once again for the great advice. The 12-volt solenoid that I got, seems to cure my disease. I just finished the assembly, and cranked the engine a few times in a row, and it works like it should.

Now I still don't know if the 6-volt solenoid was burned or not, or what gives, but at least the 12-volt solenoid seems to work. GREAT! Thanks again!