TOPIC:

Hey guys, I'm fairly new to world of motorcycles and have come to wizards here for help.

The run-down:
1982 KZ650 H2 CSR
-Bike doesn't charge with all systems running. It can get (barely) above 13V when kept at 7-8k RPM for ~20-30 seconds
-Dyna Coils & Ignition (installed by previous owner), I know about the extra power draw
- 3-phase Perm Magnet Stator, checks out, but is a little nasty. Stator casing (as in the external engine casing) is missing a screw
-Rectifier passes diode test
-Bike DOES charge just fine when headlight is disconnected (above 14V when around 4k)

My conclusion is that the stock charging system isn't quite keeping up with the discharge of the full system + after-market parts. My solution, after some more testing (need to test the power draw of the headlight specifically), is to either buy a more effecient headlight or higher-output stator. Does that sound about right? Any other tests you guys can think of?

Thanks in advance, I've been scowering this website since I got the bike and it's been super helpful so far.

I had the same problem. The Dyna S sucks a lot of power along with the Dyna 3 ohm coils couple that with the running lights and halogen headlight it wouldn't keep the battery at full charge. I went with LED's for the turn sig's and most of the other bulbes. Some like the break light and turn indicator had to be standard for them to work or the brake failure indicator to work. The biggest improvement was the HID headlight. It allowed me to use the other lights but a better choice would have been a LED headlight. I'll be getting one soon and put the HID's in my 69 Ford F250.
In the 70-80's I had a Marshall Halogen setup with a pencil beam rated at 100 watts but no running lights. The Z1's never had them and the headlight over taxed the charging system frying the rectifier and stator. I used a rectifier from a Yamaha 650 twin that was much larger and replaced the stator. The 70's era regulators were junk and overcharged the battery. I got a used one and used it until I parked it in 98. In 13 I got a used R/R combo from The Old Kaw Man that came off a KZ 1000. That worked but still wasn't getting up to full voltage. That's when I took Ed's advice and got a used Mosfet from a Polaris that works well. I got a couple knock offs from eBay that did more harm than good leading me to the REAL Mosfets. I know I need more juice and am looking for a higher output stator too.
Steve

I would make certain the battery is good. charge it with a good motorcycle smart charger then do a load test. The voltage should be 12.6 VDC after charging, but a good battery will be higher. Load test >> headlight high beam on, engine off >> 12.2 VDC. If it drops below that, then the battery may need replacing, especially if it drops well below 12.0 VDC. I don't know how the Dyna S impacts the high beam test. Then I'd check the voltage regulator output. It should be around 14.5 VDC @ 4000 rpms. If the reg-rec doesn't pass that test, I'd then replace the missing fastener & test the stator output, and If the stator & battery are good, then I'd replace the reg-rec. Again, I don't know how the Dyna S affects these tests.


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The stock system should be just fine to run the bike with the dyna coils, and should be able to handle at least another few amps before you have issues. I don't think you're having issues because the stock system is too small, it's more likely that your 36 year old regulator/rectifier and wiring are just worn out.

Changing headlights might 'fix' the problem, but really it would be hiding the problem. First thing I'd do is just give all your terminals a clean, and make sure all your grounding points are in good order. Next, check the voltage output of the alternator (the three wire that lead into the regulator/rectifier) and compare it to the manual's values. If it's too low, then look at replacing your stator. Next, if your regulator/rectifier is still reading out low values, replace that.