Simplifying wiring (small batt.,etc...)?

So I don't plan on using the elec starter at all, can I just disconnect the starter relay deal that comes off the main out lead and seal up the inputs for it? Also, right now I have a large liquid-filled battery that assume is of the stock type and assume it must be mounted upright. I've noticed some guys using a sealed, smaller 12v battery. Does anyone have any recommendations? I'd like something very flat as to hide under the seat pan - how small can I go and what are the required specs?

Sorry for all the questions, I just got into the wiring harness and have a bunch of ideas...
Thanks

Trying to balance the electrical need of the motorcycle's engine might be hard to do as at low rpm most older charging systems are not charging at all until at least 3k. A battery off of a riding mower might work but again how big is the package. You might be able to use at least 12 gauge wire for the battery connections considering that the electric starter will not be used.

www.electrosport.com has overwound stators that are supposed to be able to charge at lower rpms. A few $$ but it might be worth it.

I don't see what model you have, but the '77 KZ650's produce 14 - 15V from 1,600 RPM on up. I can't say what they put out below 1,600 RPM, but a small battery may not keep your lighting bright when you're idling or creeping along in traffic, and it may discharge to an unacceptable level if you do much city driving. The '77 KZ650 FSM calls for a 12v 10AH battery. Ed

Henry, Sorry, but not Knowing your' bike have little to offer. Many chopper/bobber guys go down to 5-7 amp maint.free units, located almost any where.and some eliminate bat, completly. some pre 80's systems kick start w/ totaly dead batterys while others sin=mply try to charge batt. the key being enough oomph to saturate coils and provide spark. then enough resistance to keep from blowing the diodes out of reg/rectifiers. many 550-650's using only 2 legs of stator for charging systemwould crank admiribly but not start.while a couple prods w/kick starter provided life. mine is one. And I welcome any/all suggestions.G

It's a 78 650B-
The previous owner had hacked away at some of the wiring. He also completely removed the left hand controls so I may just rig up some signal switches and hardwire highbeam only (instead of having high/low).

Where should I run the 12ga wires? Batt out to the ignition switch?

I really just want to have a minimal elec system while maintaining reliability and normal day-to-day driving.

I've seen race bikes with total-loss set ups and probably can't go that far, but may go blinker-less, and speedo-less. That would get rid of like 6 lights plus the auto starter would drain less. If I do go without signal lights, the only elec junk I'll need is a batt and regulator I think - would be easier to hide...

gane wrote:

Henry, Sorry, but not Knowing your' bike have little to offer. Many chopper/bobber guys go down to 5-7 amp maint.free units, located almost any where.and some eliminate bat, completly. some pre 80's systems kick start w/ totaly dead batterys while others sin=mply try to charge batt. the key being enough oomph to saturate coils and provide spark. then enough resistance to keep from blowing the diodes out of reg/rectifiers. many 550-650's using only 2 legs of stator for charging systemwould crank admiribly but not start.while a couple prods w/kick starter provided life. mine is one. And I welcome any/all suggestions.G

That sounds interesting...how is the headlight affected by this system. Thanks for the info - this sounds like what I'm looking for....

One thing you may want to consider before eliminating the high/low-beam circuit. I had the high beam filament burn out at speed on a VERY dark curvy road one night, and I can tell you flipping the switch to the low beam saved my butt big time. I really like having that second filament. Ed

650ed wrote:

One thing you may want to consider before eliminating the high/low-beam circuit. I had the high beam filament burn out at speed on a VERY dark curvy road one night, and I can tell you flipping the switch to the low beam saved my butt big time. I really like having that second filament. Ed

DAMN!
Thanks for the tip! I guess I'll get a switch for that too. Apparently one little switch can save your hide...

Henry. a charging system is imperitive. until you've lost power and lights at 60mph on a twisty road,at night, Inedde pucker factor seems like child's play. indead, I think i'll go puke again. excuse G

I use no battery on my 550, just a capacitor. I also run two 55w halogen bulbs for headlights. That's double the stock wattage. Because a capacitor doesn't store energy like a battery, it only stores enough charge for about a split second of running. But the charging system does just fine even at idle. The capacitor is there only to smooth out the charging pulses.

The only KZ's that have this option as a possibility are the ones with permanent-magnet alternators. Your 78 650 is in that category. The only difference is that your bike is a single-phase instead of my 550's 3-phase. But it may still work fine.

One thing you don't want to do in this situation is run a Dyna S. It uses too much power.

Another thing to know; before lightbulbs start to light up, they act pretty much like a short. The filament's resistance goes up only after they heat up and start glowing. Because of this I have to make sure the lights are off while starting the bike. Then just before I turn the lights on, I have to blip the throttle as I flip the light switch. At the moment I flip the switch, the headlights act as a short and the motor will lose power for a split-second. Then the lights will come on and the motor idles just fine. With a capacitor, at idle, you will notice the lights flickering more so than when running a battery.

I did add a special circuit to automatically shut the lights off when the motor stops. This way I don't have to remember to turn the lights off before starting.

At idle, because of the two headlights, the voltage does run a little lower, like 11v or 12v instead of 13v or 14v. This is fine. Contrary to some popular beliefs, you don't need a lot of voltage at idle for the ignition. This is because the dwell time becomes very large and the coils have more than ample time to charge. By having the voltage lower at idle, it ensures the regulator part of the reg/rec is not burning away excess power, so it runs cooler. (This is probably true with a battery as well, and is only relevant to regulators for permanent-magnet alternators.)

Here is a picture of the electronics on my bike.
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I'm using a 5600 uF, 50v capacitor. (I actually have two there, but one is just a spare in case the first one fails.) Because your bike is single-phase, you may need to go bigger, like 10,000 uF, 50v.

From the side, you can't really see any of the electronics. Oh, and no, the 550 doesn't have a kick start. That's a bump-start-only bike.

It's not an issue on a stock 78 kz650, but on my 550 the regulator wiring has to be altered in order to protect the capacitor during motor shutdown.

I have a small sealed battery in my Z, it's kick only as well. It's a 12VX4L-B so 12V 4A, measures 2.5x4.25x3.25". Enough for head/tail light + ignition on my Z1, not much else on there.