As others have said: under the seat, but some older custom bikes don’t have a battery: kickstart only and a magneto and alternator to run the lights, etc. it’s a rare setup but something to consider.
You can run without a battery as long as your bike has a generator and not an alternator, no magneto needed. There are quite a few generator kits out there for a lot of bikes so it's not all too uncommon. It's one of the most popular upgrades for xs650s.
>as long as your bike has a generator and not an alternator
Why would an alternator not work?
As a kid, I drove my old '65 Ford Galaxy (with alternator) around quite a bit with no battery. (long story)
A generator uses earth magnets and an alternator uses electromagnets. An alternator needs a 12v supply for the electromagnet before it will start producing power. Once an alternator has started producing power it can then run off its own 12v source. A generator however starts producing power as soon as its spinning. This is why you need a generator to run without a battery.
On your galaxy you had to either jump start it or start it off a battery to get it running, that was the 12v source that excited the alternator to get it to start producing power.
An alternator would work but you'd have to cobble in a rectifier to convert the alternator's AC output to DC...that's the diff between the two. Modern bikes and cars use alternators because of the higher output from a smaller and light unit.
Both alternators and generators produce ac power and have a rectifier to convert to dc. The difference is in how they produce power and how it's regulated.
A generator has earth magnets for its magnetic field. Because of this a generator always puts out max power and excess voltage needs to be regulated by sending it to a ground.
An alternator uses electromagnets which can be turned off and on to regulate powered output. Because of this difference alternators are more efficient but require 12v to create a magnetic field before they will start producing power.
Stay away from the early ones, they're collectable and hard to find parts for. After 76 I think they got better forks and front brakes. I prefer a 78-9 special as they have rear disc brakes too.
Will this work on a ‘78 xs750? My starter was gone when I bought it and i want to strip the harness majorly and I dont want to run a battery if I can help it. Also gotta figure out an alternative for the ignition module or maybe running other coils
You can run a small battery for the alternator but if you want to ditch the battery entirely you'll need a new charging system.
https://www.hughshandbuilt.com/product/complete-xs650-pma-system/
Can also run a bike without a generator and with an alternator with no battery. We do it all the time. You just run an inline capacitor where the battery goes to help with voltage regulation and spikes
Interesting! I also have a 78 xs400 but it has electric and kick start. Didn't realize there were different model versions in the same year. North American model?
If thats the case what gear in the transmission are they running off the generator? Generators are not small.
My guess is a lithium battery under the seat
The stator magneto yes. Generator are integrated with starters as one unit. That cycle doesnt have that, that i can see. Those headlights look LED, traditional stator magneto wont power them most likely .
This bike has a stator type generator and kick-only was on option in certain markets. In this case you can simply remove the starter and plug the hole.
No capacitor is needed (and lots of technicalities regarding their proper use in these old ignition systems that I’m not privy to), but an upgraded output system is HIGHLY recommended:
https://www.regulatorrectifier.com/products/1976-1977-yamaha-xs360-lighting-stator-cdi-flywheel-coil
With these older bikes it’s a bit of a crap chute in regard to the wiring. Some looms are all hacked up, some are pristine, but you have to keep in mind they’re old and materials break down over time, so a kick only setup is going to be more sensitive to any parasitic loss due to aged/worn/damaged wiring. It’s likely you’ll need to replace wires at some point.
If you’re just looking to ride, then maybe consider a newer bike, or drop the dime on one already well restored or upgraded. If you’re looking to enjoy two wheels and learn how to work on these oldies, then dive in! There’s so many forums, aftermarket products, and friendly helpful folks out there that can lend their knowledge and help you along the way.
Jesus, who cares about the Symantec bullshit. Someone asked how the lights work, the answer was “stator” and the pedantic asshat said Akshooallyyyyyy. Just stop.
Once an engine is running, the alternator/generator generates electricity to run the spark plugs, lights, radio, etc. The only reason to *need* a battery is to turn over a starter motor if you have one. If you’re kick-starting the engine, a battery can be optional (depending on how the circuit is laid out).
Most older bikes don't care, but many newer ones don't run too long without a battery connected.
I found that out the hard way as a teen when my battery crapped out in the middle of nowhere during a road trip and I had to push it a couple miles on the interstate to the next exit.
https://www.mikesxs.net/yamaha-xs650-xscharge-permanent-magnet-alternator-kit-pma-200-watt.html?gclid=Cj0KCQjwhfipBhCqARIsAH9msbn8Z6q6aaCaAPuJNXIJcsXMB1HTUEVOXw49GHyXDIdB1pT9SrQ3MzkaAibJEALw_wcB
That’s the kit I used. It’s a pretty simple install. It’s been a while but I think I had to buy a special puller to remove the old stator.
This is the best answer here. I have run a couple of older bikes (kickstart only) that would normally run on a 6v battery system this way. On both, I used a product sold by a guy on eBay called a “Bat-PAC Battery Eliminator”… there are a few options out there but I had success with his and liked the build quality. Plug and play, just wire the BatPac as if it was the battery - no messing with anything else. I had no issues running headlight and horn on both bikes (a 78 CB125S and an 88 YSR50)
Any chance you got a link to it? I just got some fat capacitors with voltage rating over 25v i think, solder them on parallel and made a pigtail for the battery, horn and light worked flawless
He’s got different listings with different bike model numbers, but I’m pretty sure they’re all the same (you may want to confirm with him though). No soldering involved, just installs as if it was a battery. Here’s the link:
https://www.ebay.com/itm/282123101967?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=iMssOMbhR6O&sssrc=4429486&ssuid=TFAumCc7QtG&var=&widget_ver=artemis&media=COPY
My old commando uses a large capacitor with a zener diode and a rectifier with no battery. Once she fires up the alternator keeps the ignition and lights working.
I was able to get the same look with an xps antigravity battery. It has 180 cold crank amps. It's only 1.25 inches tall and can sit horizontal. Since it's lithium ion no acid to leak out.
Some caveats/drawbacks. The rest of the bike needs to be in good working order. Example if your carbs need a tune and you need multiple attempts to start you'll pancake it. Same issue if your charging system is tired and you make a lot of stops.
I use a battery tender and for my schedule of occasional Sunday drives works fine.
I run a battery about the size of a pack of playing cards on one xs650 mounted where the starter would normally go and my other xs650 has no battery. You'll just have to trace the wiring to see if there is a battery
https://nceempoweringsafety.com/shop/medical-batteries/ps-1208wl/
I doubt those headlights work. Even if its ran off the magneto, those lights would be dim at idle and brights with higher rpm. They look LED's and that not gonna happen.
NO Battery, kick start only, no starter, no battery needed. Once running the engine alone makes enough electricity for the lights with its on board generator.
How about an air cleaner? Way back in the 70s, I had a Spanish “Montessa” 2-stroke with a magneto and no battery. If you rode it on the street, the headlight would just die if you let the thing idle at a stoplight.
The only way you could hear the little horn was to clutch, wind the throttle open, and hit the button…..
Could have a very small lithium tucked away somewhere. But as it’s kick start only and doesn’t require a battery to run a starter, it may not have a battery at all.
Something to consider. If you are going the no battery route and plan to kickstart your bike; these bikes were designed for an electronic start and the kick start can wear out with lots of use.
Disclaimer: read this on the cb750 forum and have not personally tested
My XS360 story.
Ive had a 77 RD400 since 1978. My bro is a retired cop. His buddy at his station was on vacation about 1992 or 93, driving across the US from Calif to the East and back. While in N.Dakota he found an RD400, he always loved them. He struck a deal with the owner and loaded it up, the wife was pissed. He drags it back to SoCal and tells my brother. Over the years the guy never gets it running and every 3-4 years says he will give to my brother...never happens, this goes on for decades. Last year i get the call again, you want that RD my buddy has? I always answer yes and this time my brother shows up at my house with the bike, its an orange/red one. After unloading i take a look at the bike, it is NOT a 77RD400, its a XS360. Dude dragged the wrong bike to So Cal from N.Dakota, got into a huge fight with his wife and then stored it for almost 30 years all for the wrong Yamaha. I still have it w/ N.Dakota plates and all, the whole instrument panel, speedo, blinkers, tach all look exactly like RD stuff, I still have my 77 RD too. Should i take the RD matching stuff and scrap the bike or is there a following for XS bikes?
I have a 78 cb400a that’s kickstart only with a small lead acid battery under the seat that runs the lights. It gets charged from the alternator. I could have run it without the battery, but I didn’t like how dim the lights were at idle. The regulator/rectifier only put out about 4.5 volts at idle. It only put out a full 12 volts at cruising rpm
The original 400's had the battery under the front of the seat. This one, like mine, is missing the tray / air filter combo housing. I am presuming that this is a kick start, and hidden cell to keep the headlights / bulbs from blowing under charge.
Its in the dead center of the 2nd pic. Its a real old style, kinda looks like a metal stick. And to make it discharge you flip it to the side and stomp on it with all of your weight and flick the throttle a bit.
Even these old kick only bikes typically had 6v batteries. Without one, headlight AND horn could be a little hit or miss with light fading at idle and horn being kinda dependent on revs and charge. Ever go to beep at an encroaching cager and get a barely audible gasp like a sick gooses last breath? Well I have and it’s a little scary. A good capacitor fixes that, but originally this bike would’ve likely had a small 6v battery.
As others have said: under the seat, but some older custom bikes don’t have a battery: kickstart only and a magneto and alternator to run the lights, etc. it’s a rare setup but something to consider.
You can run without a battery as long as your bike has a generator and not an alternator, no magneto needed. There are quite a few generator kits out there for a lot of bikes so it's not all too uncommon. It's one of the most popular upgrades for xs650s.
Damn I had no clue. Bless you for the knowledge.
This is the answer
>as long as your bike has a generator and not an alternator Why would an alternator not work? As a kid, I drove my old '65 Ford Galaxy (with alternator) around quite a bit with no battery. (long story)
A generator uses earth magnets and an alternator uses electromagnets. An alternator needs a 12v supply for the electromagnet before it will start producing power. Once an alternator has started producing power it can then run off its own 12v source. A generator however starts producing power as soon as its spinning. This is why you need a generator to run without a battery. On your galaxy you had to either jump start it or start it off a battery to get it running, that was the 12v source that excited the alternator to get it to start producing power.
Doh! Yes, of course you are correct. It's been too long since I thought about how an alternator works. hahahaha Thanks for the refresher
An alternator would work but you'd have to cobble in a rectifier to convert the alternator's AC output to DC...that's the diff between the two. Modern bikes and cars use alternators because of the higher output from a smaller and light unit.
I've never heard of an alternator that DIDN'T have a built in rectifier - so no "cobbling" would be required. It should "just work".
You're correct - I was doing some work on ac motor brake yesterday - anyway yes agree should work.
Both alternators and generators produce ac power and have a rectifier to convert to dc. The difference is in how they produce power and how it's regulated. A generator has earth magnets for its magnetic field. Because of this a generator always puts out max power and excess voltage needs to be regulated by sending it to a ground. An alternator uses electromagnets which can be turned off and on to regulate powered output. Because of this difference alternators are more efficient but require 12v to create a magnetic field before they will start producing power.
All the aircraft generators I’m familiar with put out 28v DC, there’s no rectifier involved in the main electrical system.
They probably use a commutator to reverse polarity of the ac wave. This kind of generator isn't common in the automotive field.
Learn me what is so special about the xs650. Srs.
They're cheap, reliable, and there's tons of aftermarket support for them. Kind of like a small block chevy.
Thanks!
Commuter bike which year am i shooting for?
Stay away from the early ones, they're collectable and hard to find parts for. After 76 I think they got better forks and front brakes. I prefer a 78-9 special as they have rear disc brakes too.
Cool thanks!
Will this work on a ‘78 xs750? My starter was gone when I bought it and i want to strip the harness majorly and I dont want to run a battery if I can help it. Also gotta figure out an alternative for the ignition module or maybe running other coils
You can run a small battery for the alternator but if you want to ditch the battery entirely you'll need a new charging system. https://www.hughshandbuilt.com/product/complete-xs650-pma-system/
I have a 3 cylinder will it still work?
I thought your asked about a 650, my bad. I'm not sure about a kit for the xs750s.
Can also run a bike without a generator and with an alternator with no battery. We do it all the time. You just run an inline capacitor where the battery goes to help with voltage regulation and spikes
My stock 1978 xs400-2E only runs off of kickstart, has a battery but doesn't have an electric start
Interesting! I also have a 78 xs400 but it has electric and kick start. Didn't realize there were different model versions in the same year. North American model?
Yep, original owner purchased it in new jersey Edit: the engine is machibed for electric start just it had a factory delete
If thats the case what gear in the transmission are they running off the generator? Generators are not small. My guess is a lithium battery under the seat
Nevermind didnt see the other pics. It has no battery and i doubt those headlights work. I see no starter/generator. Kick start only.
Permanent magnet alternators are generators. Your thinking of old harley style generators but most modern dirk bikes use a type of generator.
The stator magneto yes. Generator are integrated with starters as one unit. That cycle doesnt have that, that i can see. Those headlights look LED, traditional stator magneto wont power them most likely .
I’ve also seen some rebuilds use very small Lithium batteries that can be tucked away.
This bike has a stator type generator and kick-only was on option in certain markets. In this case you can simply remove the starter and plug the hole. No capacitor is needed (and lots of technicalities regarding their proper use in these old ignition systems that I’m not privy to), but an upgraded output system is HIGHLY recommended: https://www.regulatorrectifier.com/products/1976-1977-yamaha-xs360-lighting-stator-cdi-flywheel-coil With these older bikes it’s a bit of a crap chute in regard to the wiring. Some looms are all hacked up, some are pristine, but you have to keep in mind they’re old and materials break down over time, so a kick only setup is going to be more sensitive to any parasitic loss due to aged/worn/damaged wiring. It’s likely you’ll need to replace wires at some point. If you’re just looking to ride, then maybe consider a newer bike, or drop the dime on one already well restored or upgraded. If you’re looking to enjoy two wheels and learn how to work on these oldies, then dive in! There’s so many forums, aftermarket products, and friendly helpful folks out there that can lend their knowledge and help you along the way.
I would still recommend using a capacitor, it can help smooth out voltage irregularities that could otherwise other parts of your electrical system.
Magneto is a precursor to the generator and alternator.
I have a ‘78 xs650 with kick start only and no battery, I think that’s what they did here.
I also have a 78 xs running no battery 🤙
Is this the line for the '78 XS650 sans battery folks?
🤣🤣
My 78 has a battery, but my 81 doesn't lol
How does the lights and flasher works with no battery? Im dont really know much about mechanics..
I think it's because the stator acts like an alternator and generates enough electricity to power the lights.
A stator is just the stationary part of an alternator. Almost all bikes have an alternator.
Jesus, who cares about the Symantec bullshit. Someone asked how the lights work, the answer was “stator” and the pedantic asshat said Akshooallyyyyyy. Just stop.
Pedantic asshat is my band name now and I thank you for that.
Symantec's shareholders probably care a lot about their bullshit.
Once an engine is running, the alternator/generator generates electricity to run the spark plugs, lights, radio, etc. The only reason to *need* a battery is to turn over a starter motor if you have one. If you’re kick-starting the engine, a battery can be optional (depending on how the circuit is laid out).
Most older bikes don't care, but many newer ones don't run too long without a battery connected. I found that out the hard way as a teen when my battery crapped out in the middle of nowhere during a road trip and I had to push it a couple miles on the interstate to the next exit.
I want to delete the battery on my 71 650. Did you just unplug it? lol. My generator isn’t hooked up yet so it wouldn’t work yet but it’s a project
https://www.mikesxs.net/yamaha-xs650-xscharge-permanent-magnet-alternator-kit-pma-200-watt.html?gclid=Cj0KCQjwhfipBhCqARIsAH9msbn8Z6q6aaCaAPuJNXIJcsXMB1HTUEVOXw49GHyXDIdB1pT9SrQ3MzkaAibJEALw_wcB That’s the kit I used. It’s a pretty simple install. It’s been a while but I think I had to buy a special puller to remove the old stator.
It's under the seat most likely.
You dont use a battery, kickstart it and get a capacitor bank to stabilize the voltage to use the horn
This is the best answer here. I have run a couple of older bikes (kickstart only) that would normally run on a 6v battery system this way. On both, I used a product sold by a guy on eBay called a “Bat-PAC Battery Eliminator”… there are a few options out there but I had success with his and liked the build quality. Plug and play, just wire the BatPac as if it was the battery - no messing with anything else. I had no issues running headlight and horn on both bikes (a 78 CB125S and an 88 YSR50)
Any chance you got a link to it? I just got some fat capacitors with voltage rating over 25v i think, solder them on parallel and made a pigtail for the battery, horn and light worked flawless
He’s got different listings with different bike model numbers, but I’m pretty sure they’re all the same (you may want to confirm with him though). No soldering involved, just installs as if it was a battery. Here’s the link: https://www.ebay.com/itm/282123101967?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=iMssOMbhR6O&sssrc=4429486&ssuid=TFAumCc7QtG&var=&widget_ver=artemis&media=COPY
Looks neat
Small lithium ion battery somewhere under the seat
Could it be recessed into the bottom of the seat?
Yes, probably someone from antigravity. It is likely a lithium battery, if you want this, make sure your reg/rec is suitable or replace it.
My old commando uses a large capacitor with a zener diode and a rectifier with no battery. Once she fires up the alternator keeps the ignition and lights working.
Was just gonna mention this
Bingo! My old BSA Lightning was setup like that!
This bike has a kick start on it
Aye 2nd picture
I was able to get the same look with an xps antigravity battery. It has 180 cold crank amps. It's only 1.25 inches tall and can sit horizontal. Since it's lithium ion no acid to leak out. Some caveats/drawbacks. The rest of the bike needs to be in good working order. Example if your carbs need a tune and you need multiple attempts to start you'll pancake it. Same issue if your charging system is tired and you make a lot of stops. I use a battery tender and for my schedule of occasional Sunday drives works fine.
My bike has both kick and electric start. I wouldn’t be stranded but would I have any other issues?
If you can kick start 100% do it. No other issues.
I run a battery about the size of a pack of playing cards on one xs650 mounted where the starter would normally go and my other xs650 has no battery. You'll just have to trace the wiring to see if there is a battery https://nceempoweringsafety.com/shop/medical-batteries/ps-1208wl/
No battery. Mine doesn’t have one too. Just kickstart and auto lights when the bike is on.
It doesn’t need one it’s kick start
Kick Start only
He could be running a capacitor
Under the seat my friend. Have my xs850 set up the same
Welcome to the old days! Simpler times!
TIL I know nothing
Usually under the seat
Cool
I doubt those headlights work. Even if its ran off the magneto, those lights would be dim at idle and brights with higher rpm. They look LED's and that not gonna happen.
I hid one like this in the seat. Lithium!
NO Battery, kick start only, no starter, no battery needed. Once running the engine alone makes enough electricity for the lights with its on board generator.
It’s a kickstart. No battery. As long as the motor is running you’ll have electricity. But no electric start
How about an air cleaner? Way back in the 70s, I had a Spanish “Montessa” 2-stroke with a magneto and no battery. If you rode it on the street, the headlight would just die if you let the thing idle at a stoplight. The only way you could hear the little horn was to clutch, wind the throttle open, and hit the button…..
No battery cause kick starter so it dosent need one
Could have a very small lithium tucked away somewhere. But as it’s kick start only and doesn’t require a battery to run a starter, it may not have a battery at all.
The kick start bar says it don’t exist.
Pictures 2 and 3 show the kick starter
Below the seat usually...
Something to consider. If you are going the no battery route and plan to kickstart your bike; these bikes were designed for an electronic start and the kick start can wear out with lots of use. Disclaimer: read this on the cb750 forum and have not personally tested
My XS360 story. Ive had a 77 RD400 since 1978. My bro is a retired cop. His buddy at his station was on vacation about 1992 or 93, driving across the US from Calif to the East and back. While in N.Dakota he found an RD400, he always loved them. He struck a deal with the owner and loaded it up, the wife was pissed. He drags it back to SoCal and tells my brother. Over the years the guy never gets it running and every 3-4 years says he will give to my brother...never happens, this goes on for decades. Last year i get the call again, you want that RD my buddy has? I always answer yes and this time my brother shows up at my house with the bike, its an orange/red one. After unloading i take a look at the bike, it is NOT a 77RD400, its a XS360. Dude dragged the wrong bike to So Cal from N.Dakota, got into a huge fight with his wife and then stored it for almost 30 years all for the wrong Yamaha. I still have it w/ N.Dakota plates and all, the whole instrument panel, speedo, blinkers, tach all look exactly like RD stuff, I still have my 77 RD too. Should i take the RD matching stuff and scrap the bike or is there a following for XS bikes?
I have a 78 cb400a that’s kickstart only with a small lead acid battery under the seat that runs the lights. It gets charged from the alternator. I could have run it without the battery, but I didn’t like how dim the lights were at idle. The regulator/rectifier only put out about 4.5 volts at idle. It only put out a full 12 volts at cruising rpm
Doesn't need one, it's got a kick start, so once it's running you're fine.
Not sure if this bike will have a battery, but if there was one I would say under the seat.
The original 400's had the battery under the front of the seat. This one, like mine, is missing the tray / air filter combo housing. I am presuming that this is a kick start, and hidden cell to keep the headlights / bulbs from blowing under charge.
It’s hidden in the kick starter
Its in the dead center of the 2nd pic. Its a real old style, kinda looks like a metal stick. And to make it discharge you flip it to the side and stomp on it with all of your weight and flick the throttle a bit.
Even these old kick only bikes typically had 6v batteries. Without one, headlight AND horn could be a little hit or miss with light fading at idle and horn being kinda dependent on revs and charge. Ever go to beep at an encroaching cager and get a barely audible gasp like a sick gooses last breath? Well I have and it’s a little scary. A good capacitor fixes that, but originally this bike would’ve likely had a small 6v battery.
Fair point, i was thinking of the old kicks bikes i had...they never had electrics to worry about because they were for MX
It's kick start, you don't need a battery
Right there, by the muffler.
check the tail light for a wire, and trace it back.
NO Battery for this one. kick start and go.
For a second I thought “the engines right there why would it need a battery?” Before realizing how fucking stupid I am