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PostPosted: Mon Sep 06, 2021 11:03 am
by Jeddarr
Just purchased a 1948 lightweight frame with a 1951 motor. It was restored many years ago and then just sat in a shed. Everything looks in order with new parts. After cleaning the tank, carburetor and new battery I was able to start it without much difficulty. Unfortunately after running a few minutes it’s dies and the battery has to be recharged. I replaced the ignition coil, voltage regulator and condenser. Generator brushes look new. Obviously the battery is not being charged and not sure where I should go next. Any advice is appreciated

Re: Newbie

PostPosted: Mon Sep 06, 2021 1:11 pm
by 250_Sprint
Congratulations. Have fun with it. RIDE IT!

Check all of the electrical connections. ALL CONNECTIONS.
Make sure they are clean of corrosion.
Make sure all connections are tight.
Check continuity of all of the wires.

Don’t take for granted there are no problems with the restoration.
Test the new parts to make sure the parts are good.

If all checks out good, get a 6 volt source which will last longer than the little battery in the bike.
Test the new parts. Make sure they work.

Use a multimeter (even digital ones are inexpensive) to follow the power
From the battery to the generator
From generator to the regulator
From the regulator to the battery

I see you have an ammeter. Take the ammeter out of the circuit. There may be a defect in the meter.

Good Luck.

Re: Newbie

PostPosted: Mon Sep 06, 2021 4:46 pm
by Jeddarr
thanks so much! I will get started. didn't think about the ammeter. the gauge doesn't seem to move at all when I increase the throttle. Wasn't sure if it was supposed to or not.

Re: Newbie

PostPosted: Tue Sep 07, 2021 7:24 am
by HarryM
To keep it simple, you have basically answered your own question. Obviously, your battery is not Charging. Forget Coil and Condenser.
1. It runs for a few minutes until the battery goes dead, I assume it will do the same after you recharge the battery.
2. Polarize your Generator/Regulator. It is common for these to lose their Polarization when not use for a long period of time or when removed for some reason.
Check your battery voltage with Not running (6-6.2 V) and then when running (6.5 -7V) The voltage should be more than when not running. Check with engine running at a higher RPM, may not show higher voltage at idle speed.

Re: Newbie

PostPosted: Tue Sep 07, 2021 8:23 am
by 250_Sprint
A mechanical ammeter needle will only deflect if the charging circuit is working properly, the ammeter is not defective and if the ammeter is the proper ampere range for your application.
Assuming your charging circuit and ammeter are functioning properly, but the range of the meter is +30 amperes / -30 amperes, you may not ‘see’ the needle deflect. The range of the meter is too high for your application. I have a meter from a Ford Model T and it’s range is +20 / -20. These bikes use a range of +15 / -15. The needle would deflect more if the range was +10 / -10.

Make sure all of the wiring is continuous with no breaks.
Make sure all terminal ends are clean of corrosion. Corrosion adds resistance. Elections hate that!
Make sure all electronic devices in the circuit are functioning as designed.
Don’t assume a new part is functioning properly or you may be chasing your tail.
With the engine not running, a 6 volt power source and a multimeter, you can make sure electricity is getting to where it needs to get, then check to see if it is coming out as it should.

I have a battery charger rated at 6V, 1.25A I use as a power source for 6 volt projects.

Good luck. Have fun. Ask questions.

Re: Newbie

PostPosted: Tue Sep 07, 2021 2:49 pm
by Jeddarr
thanks HarryM. the generator is definitely not putting out any voltage when running. Ive never polarized a battery but tried touching a wire from the battery terminal on the regulator to the gen terminal and got a spark but still no voltage from the generator. Is that the correct way to polarize? could it be I need to do that with the neg terminal of the battery? also any tricks on decreasing the leak from the petcock? cleaned it and replaced washers but still leaks at the lever. thanks for all the input

Re: Newbie

PostPosted: Tue Sep 07, 2021 3:16 pm
by Jgeekie54
I will Leave you to the professionals.
Good luck

Re: Newbie

PostPosted: Tue Sep 07, 2021 6:33 pm
by HarryM
Appears you did the Polarizing correctly. The spark is all it takes to Polarize, (Generator & Regulator) this is enough to recharge (magnetize) the pole pieces for the Generator Coils so they will produce a Magnetic Field which the Armature needs to produce a voltage.
Some wiring assemblies contain a Fuse check for one.
If you find no wiring problems at the Generator my best guess is you will need to remove it and have it shop tested.

Your fuel shut off valve unit – If you mean the valve is not shutting off and is an aftermarket assembly, all that I have purchased LEAK (I have 4), gave up and installed New later similar assembly (only one valve control, On/Off/Res. If you use the standard solid fuel line and want to use it with the newer assembly send it to MUTT he will install the proper fuel fitting.

Re: Newbie

PostPosted: Wed Sep 08, 2021 1:43 pm
by Jeddarr
Thanks again. Have to leave town for a few days but will get back to it soon

Re: Newbie

PostPosted: Wed Sep 08, 2021 6:11 pm
by 250_Sprint
Again, make sure all of the wire terminal ends and their contact areas are clean of rust, dirt, oil, and such. Don’t rely on “a fully restored” story.

Remember, the current induced in the armature windings is picked up from the commutator segments by the 4 brushes.
The end of the brush wires need to be clean and tight.
It is recommended, before removing and completely disassembling generator, check the brushes and brush springs.
Polish the commutator with #00 sandpaper.
Make sure brushes are not worn to the point where the brush wire limits intact with the commutator.
…and have fun.