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Discussion Starter · #1 ·
I tried this one last night on the Yahoo BSA forum, but I figured someone here probably knows the answer to this one:

I put a new battery in my '70 Thunderbolt a few years ago when I first rebuilt it and have had no poblems with it until recently. I have noticed in the past months that the battery has been holding less and less of a charge (headlight barely glows when the engine's not running), and recently it has become much harder to start when it's been sitting for a while.
I have always been able to keep the ignition system working well and it usually starts on the first or second kick, but now I have to kick and kick for a while as if it's building up a charge before it fires. I would like to try running it without a battery, and I seem to remember that these bikes can do that from the factory, but I wanted to know If there are any problems caused by running without, and what to do with the battery leads once disconnected?

thanks!

-nate
 

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Are you running points? boyer? sparx?

my 70 A65 requires at minimum 12.3v to fire the boyer. anything less might as well be dead. recharging isnt really the answer if it cant hold above 12.3v

there are several products on the market that will fire your A65 without the battery. whether they fire electronic ignitions I cant say.
 

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Triumps and BSA racers used a factory system that used two large capacitors (Blue Meanies) that held enough power to start the bike and ran off the normal charging system. Harleys used a magneto (doesn't require any outside power source) and the normal charging system to run lites, ect. These system were used to cut weight for racing but have been used sucessfuly on the street. A Big draw backs are: (1) poor lighting at low engine rpm's to the point of the brake lights killing the bike sometimes. (2) runaway voltage at high rpm's blowing the lights out. A much better choice would be to keep what you have. Most likely your battery has just sat around to long and needs replacing. Also use a voltmeter to check your output when running it should be atleast 1volt above battery voltage. (12v system with key off = 13v when running). Also check the electrolite level. Low levels kill battries.
 

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Discussion Starter · #5 ·
Thanks for the quick replies!
I am running points (normally) with out any problem, I just clean and adjust them once in a while and she runs pretty well. I think for this bike I will end up replacing the battery, but the information is good because I will be running without on the new bike (441 bobber, pics soon I swear).
Has anyone tried one of those "Bat-Pac" devices that are supposed to stabilize the voltage and help when starting? (http://bat-pac.com)
I may try one, but I'd be curious to know if anyone has experience with it.

Thanks again,
Nate
 

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Nope.. but it looks like an improved version of the factory batteryless systems. Are you running an electronic regulator or the factory zener diode set up? If you don't have an electronic unit (for battery systems only) get one. They really make for a dependable electrical system.
 
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