How Long will motor run without charging battery?

73 850.

NO headlight, no tail light, no headlamp shell lights, no turn signals, just occasional brake light.


Drawing a fully charged battery to run ignition only.

I STILL can't figure out why my system will not recharge the battery. Working on it slowly, piece by piece, tracing the wires

But until then, the weather here is still warm enough to ride a little.

So, any ideas on how long, ignition only discharge rate, I could ride without the battery bringing me to a stop?

Oh yeah, Tri Spark ignition.

highdesert said:

73 850.


I STILL can't figure out why my system will not recharge the battery. Working on it slowly, piece by piece, tracing the wires

So, any ideas on how long, ignition only discharge rate, I could ride without the battery bringing me to a stop?

Oh yeah, Tri Spark ignition.

Click to expand...

Try putting a multi-meter on the 20V DC setting and put the probes on the battery terminals and reading what the battery holds as is, if good its normally around 12.5. Then start the bike and put the probes on again and rev the motor to 3,000rpm. The input voltage should jump to around 14V DC. If it doesn't then the recifier is the next thing to test or swap out. The solid state type are cheap, around $15. If the rectifier is OK, then the only source can be the alternator itself. You can do a another test on the 2 wires coming off that connected to a headlamp, but to read the output in Volts and Amps check other threads in the forum or speak with an auto electrician. Be careful handling wires with power coming off the alternator.

I have had a analogue Boyer run for about 4 to 5 hours before the ignition breaks down, Boyers are low voltage intolerant, i.e. 10V and thats about it. I understand the Tri Spark goes down to 8V so possibly you might squeeze 6 hours out of a healthy battery?

Mick

Hard to say how far it will run as it depends on a lot of things. Give me a call and maybe we can figure out something. Jim cell 719-821-5708

A typical EI system requires 1.5 amps. You will double that number each time you tap the brakes (20 watt bulb). So assuming an average load of 2 amps, and a freshly charged 10 A-h battery, you can expect 4 hours of operation, at the end of which the voltage will have declined to 9.5 volts. At this point the battery will go south in a hurry, so you might squeeze another 30 minutes or so. If you're not home by this time, you'll be traveling in first gear only at max revs, in an attempt to keep the bike running with the constant 28 degrees of advance that the under-voltaged IE will lock to (ask me how I know).

Rick, thanks that helps.

But why only first gear, and why at maximum rpm if fully advance is 3000 rpm?

Would not any gear above 3000 rpm keep it running then? For a while

My old 750 with points and capacitor would start and run without the battery as long as you didn't turn the headlight on and let the revs dip below 3K. A boyer won't function without certain minimum voltage. If the capacitor is still in-line, it serves to excite the alternator coils and make it begin shooting juice into the wires, but without the battery, I don't think there's enough to start it with a Boyer.

Funny - this is a question I ask myself every time I start my race bike. I run a Boyer with total loss, using a YTZ7S Yuasa, which is 6ah. I can usually get at least a day out of it, which would be about 60-80 minutes of track time, but I never push it like that - I always put it on a charger when I come in. The Boyer will break up at anything below about 10 volts. Pazons are much less fussy about voltage. (I think they are set to run all the way down to about 6 volts.) Because of this, I want one, but I'm too cheap sometimes.

But I will say, when an electronic ignition goes, it goes. You won't be riding the bike home.

Trixie Combat with factory points and with blue can and normal size 9ah battery she would idle 600 rpm until it ran out of gas as sure didn't over heat any.

Ms Peel Combat with analog boyer and blue can and no battery I could kick start at times or get a ~20 mph tow off and run fine, if rev's/volts keep up about 2000/12ish, learned when I kept missing the ground throwing myself at it hard as I could in chiacanes but the battery and fiber side cover got scared so jumped ship down a hill side never seen again. Didn't notice till slowed up on idle too much to wave at farmer friend, noticed just wires hanging out, couldn't kick off
so he towed us off to start fine and get home ok as I watched color LED and kept it mostly in green rpm 1600-1800.

On Ms Peel - analog boyer, blue can and 1.2 ah pocket size battery, Sparx 3 phase 210 watt alternator, she would only idle below 1200 for ~4 min till V's dropped below 10.5 and Boyer gagged - missfired - stalled out. Idle slowly dropped prior to dying. No lights on just ignition draw. If I was vigorous and lucky I could kicker off sans battery but was 50/50. I bet a couple 9V batteries hooked up would make her one easy kick start then alternator would pick up the slack.

Next Peel with 3 wire v sensing charger should idle 500 rpm on optic/digital CD ignition till out of gas. Mainly pensive of low oil pressure flow that slow. In her minimal configuration I'll remove charger 8 lb and put in 4 to 6 ah battery for an event or ATV trail play.

Only first gear would keep the revs up on even the most modest grades. I was also faced with a speed limit problem. Anyway, 2800, 3000, you get the idea. Since then, I aleays check the idle voltage with headlight on before leaving, and use battery tenders, and ride each bike more often. Very disagreeable experience. This occurred on my Victor with a Pazon. Not the Pazon's fault, this one is on me.

When I first put my 850 together I was running it total loss, with a Pazon and an 8 ah AGM battery. All I had wired were brake lights and ignition. I had an LED voltage monitor to keep track and I'd plug it in to the battery tender after every ride. The longest rides I did were about an hour, never any problems. The lowest I got on the voltage monitor was solid yellow, which (I think) is 11.5 - 12.0 volts or something like that.

My 750 with points and original Lucas 2MC capacitor will start and run without the battery but I've never tried riding it like that.

Debby

If you're running a Boyer?

About 35 Miles

>>>>I have had a analogue Boyer run for about 4 to 5 hours before the ignition breaks down, Boyers are low voltage intolerant, i.e. 10V and thats about it. I understand the Tri Spark goes down to 8V so possibly you might squeeze 6 hours out of a healthy battery?

MickML <<<<

The Mk III Boyers where sensitive to voltage, the Mk IVs and the Micro-Digitals are on par with Pazon's and Tri-Sparks, and are considerably less expensive then either. I like the Tri-Spark for it's amazing compactness, I like the Boyer for it's 5 year warranty and consistent performance.

RS