Fixed a "hard starting" scooter today with a big ass capacitor.

   #1  

Master-Cylinder

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My buddy's daughter has a Yamaha 50cc Vino scooter at college that just doesn't turn over fast enough for him or her when you hit the button, it takes like a second for the starter motor to get up to speed. He's replaced the battery, the starter relay and had the starter apart to clean the brushes and slip rings/commutator. Still too much of a lag for him. Can't put another battery in it because there is no room, and the one it takes only fits it, and the main fuse is part of the batteries connector.

So I told him to go to the car stereo joint and get a big ass car audio system cap and I'll stick it in. I told him to get a 1 farad, he got a 5000 mfd or what ever half a 1 farad is. It a little bigger than a soda can in diameter and an inch or two taller. It has a digital voltage display on it and some circuitry so it doesn't throw a bolt of lightening when you first connect it.

Fugger works like a charm, hit the button and it spins right up. I also beefed up the wiring to the real and the motor.

I've been wanting to try this for decades, but never got around to it.
 
   #6  

A23

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coulda used that on my FXR...

I had to drill a hole in the backside of the starter and jam an icepick in there to get it to start.
 
   #7  

BilletMan

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OK, this cranky old fuck hasn't completely lost it! Yet. That's a fantastic fix! Fuckin Aye, high five....:up::up:
 
   #8  
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My buddy's daughter has a Yamaha 50cc Vino scooter at college that just doesn't turn over fast enough for him or her when you hit the button, it takes like a second for the starter motor to get up to speed. He's replaced the battery, the starter relay and had the starter apart to clean the brushes and slip rings/commutator. Still too much of a lag for him. Can't put another battery in it because there is no room, and the one it takes only fits it, and the main fuse is part of the batteries connector.

So I told him to go to the car stereo joint and get a big ass car audio system cap and I'll stick it in. I told him to get a 1 farad, he got a 5000 mfd or what ever half a 1 farad is. It a little bigger than a soda can in diameter and an inch or two taller. It has a digital voltage display on it and some circuitry so it doesn't throw a bolt of lightening when you first connect it.

Fugger works like a charm, hit the button and it spins right up. I also beefed up the wiring to the real and the motor.

I've been wanting to try this for decades, but never got around to it.
I've got one of those big caps with the voltmeter sitting in the garage.
How did you wire it into the starting circuit?
Thanks,
 
   #9  

BilletMan

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My Honda CB-350FOUR will crank on the battery and not fire sometimes when cold. This dates back to when my DAD bought one in 1973.....The engine doesn't start with electric starter, but fires immediately and enthusiastically when you just kick the starter lever after trying with the electric starter....
 
   #11  

Austin_F

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so the 1 farad cap could have been too much, or it wouldn't hurt anything?
 
   #12  
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After you turn the key off, it take aboot 30 seconds for it to discharge. I told him to turn the key on, wait half a second to charge up and then hit the button.
So not only parallel to the battery, but switched on by the key. [so the cap is not energized all the time]
That's the part I'm not clear on. Did you put a relay in the circuit?
 
   #14  
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My Honda CB-350FOUR will crank on the battery and not fire sometimes when cold. This dates back to when my DAD bought one in 1973.....The engine doesn't start with electric starter, but fires immediately and enthusiastically when you just kick the starter lever after trying with the electric starter....
Low voltage to the ignition system, we get stuff like that every now and then. If a motorcycle has the headlight on allah tyme and no cut out when the starter button is pushed, it can cause that. Especially if the brake light is stuck on too.
 
   #15  
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so the 1 farad cap could have been too much, or it wouldn't hurt anything?
I wanted him to get a 1 farad, the more the better. The cool thing with the one we installed, with the LED readout on, it looks like a bomb is strapped to the bottom of the scooter. The cap is mounted between the lower trim panel and the floorboard, it fit like a glove, just the end with the display is visible.
 
   #23  

DaCat

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Cool fix MC. Is there no parasitic current draw when the system is standing?

I would've thought it would drain the battery after a few days, even more so with a display.
 
   #24  
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Cool fix MC. Is there no parasitic current draw when the system is standing?

I would've thought it would drain the battery after a few days, even more so with a display.
Not really anywhere for it to go/drain, unless it fails completely, the scooter has a kickstarter for back up. . Everything electronic is filled with capacitors. After the key is turned off, the caps display shows a slow discharge until it gets to around 8 volts and then goes blank. These car audio caps are more than just a big ass capacitor, you can see a circuit board under the protective cover, just can't see it well enough to she whats there. It may decouple itself if it doesn't sense a change in status.

And, who hasn't made a simple RC circuit for a timer?

And still, to this day, there are old Triumphs and the like with a battery eliminator, which is nothing more than a cheap $5.00 capacitor. Guys have been using them for decades. I think it all started when those old turds were made into hard tails and they would break the old 60'~70's batteries internally from road shock and vibration. I put one on some old sled a couple years ago because the guy wanted to go "authentic 60's rat bike", it was.
 
   #26  
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:up: I get it now, I wasn't seeing the connection after the ignition switch.
It's not connected to the ignition switch at all. It connected pretty much right to the battery, it has full battery voltage to it allah the tyme. BUT, it appears if something isn't making a bit of demand on it, it goes dorment. I say it is connected right to the battery but not really since the connection to the battery is not accessible. The positive lead of the cap is soldered to the positive (battery) side of the starter relay wire, because it is easy to get to. The negative lead of the cap is grounded at the starters ground. But, it is, for all intents and purposes, absolutely the same as being connected right at the battery, potential wise.

My cable TV box turns itself off If you don't change the channel or volume or anything. It shuts off after four hours. A screen pops up stating push any button or cable box will turn off, or something like that.
 
   #28  

Austin_F

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So comparing 1 fatad to half a farad, whats the difference? More amps?
 
   #29  
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So comparing 1 fatad to half a farad, whats the difference? More amps?
I used to know all this stuff 40 years ago. The way to properly size it would have been to measure the amount of peak/surge power the starter needed to get going. And since we only had a day to dick with it, I told him to get a 1 farad, he cheaped out and got a 1/2. From my days with car stereos, a bigger cap was always better. A one farad cap at 12.5 volts may have 78.125 joules of energy, a 1/2 farad would have 39.063 ish. It's all aboot the instantaneous dumping of power. A capacitor can shoot it's load instantly, a battery can't.
There is a long haired math equation use can use if you really want to know.
 
   #30  

DaCat

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It's not connected to the ignition switch at all. It connected pretty much right to the battery, it has full battery voltage to it allah the tyme. BUT, it appears if something isn't making a bit of demand on it, it goes dorment. I say it is connected right to the battery but not really since the connection to the battery is not accessible. The positive lead of the cap is soldered to the positive (battery) side of the starter relay wire, because it is easy to get to. The negative lead of the cap is grounded at the starters ground. But, it is, for all intents and purposes, absolutely the same as being connected right at the battery, potential wise.

My cable TV box turns itself off If you don't change the channel or volume or anything. It shuts off after four hours. A screen pops up stating push any button or cable box will turn off, or something like that.
Your TV box has a micro-controller in it and that goes into sleep mode, it's different to a cap connected across the battery. The processor circuit draws micro amps in sleep mode.

If I were you I would measure what the current draw is from the cap connected across the battery after it goes into 'sleep mode', maybe also measure when it's awake.

I would suspect the cap to discharge the battery if the bike isn't used for a while (a few days, maybe a week).

I could be wrong and you do in fact have an intelligent cap... more intelligent than me, but that won't be very surprising anyway. :razz:
 
   #31  

DaCat

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So comparing 1 fatad to half a farad, whats the difference? More amps?
What MC said is pretty accurate. A 1Farad cap has double the oomph of a 0.5F cap.

In a more scientific method: when you short the terminals after it has been charged, the blue spark is louder and brighter on the 1F cap :wink2:
 
   #32  
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Your TV box has a micro-controller in it and that goes into sleep mode, it's different to a cap connected across the battery. The processor circuit draws micro amps in sleep mode.

If I were you I would measure what the current draw is from the cap connected across the battery after it goes into 'sleep mode', maybe also measure when it's awake.

I would suspect the cap to discharge the battery if the bike isn't used for a while (a few days, maybe a week).

I could be wrong and you do in fact have an intelligent cap... more intelligent than me, but that won't be very surprising anyway. :razz:

Once it has filled with electrons, it should be good. It, and the battery, will seek an equal level (potential) and just sit there... until something fails.

You never charged up a capacitor and left it laying around for someone to pick up, or tossed a live one to someone?

Back in the old tube type CRT TV days, you take the back off to replace a tube and had to make sure you didn't get lit up by a capacitor or two, even days or weeks after you'd unplugged it.

Speaking of tubes, remember when every drugstore or hardware store had a tube tester and a cabinet full of tubes? Or shooting the CRT with a gun at the dump? Can't have that kind of fun now days.
 
   #33  

DaCat

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Once it has filled with electrons, it should be good. It, and the battery, will seek an equal level (potential) and just sit there... until something fails.

You never charged up a capacitor and left it laying around for someone to pick up, or tossed a live one to someone?

Back in the old tube type CRT TV days, you take the back off to replace a tube and had to make sure you didn't get lit up by a capacitor or two, even days or weeks after you'd unplugged it.

Speaking of tubes, remember when every drugstore or hardware store had a tube tester and a cabinet full of tubes? Or shooting the CRT with a gun at the dump? Can't have that kind of fun now days.
:lol: Good times for sure... we would even put the electrolytic caps into the mains plug points. We have an on/off switch on our mains plugs, so when the appy gets back to his desk after lunch there was fun to be had. How a shard of metal never got into an eye or something is beyond me.

As for the internal resistance of a cap, it will self discharge after some time. Batteries do this too :wink2:

No worries, if it works then you have a winner, all good :up: :up:
 
   #35  
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:lol: Good times for sure... we would even put the electrolytic caps into the mains plug points. We have an on/off switch on our mains plugs, so when the appy gets back to his desk after lunch there was fun to be had. How a shard of metal never got into an eye or something is beyond me.

As for the internal resistance of a cap, it will self discharge after some time. Batteries do this too :wink2:

No worries, if it works then you have a winner, all good :up::up:
One of the other thing we would do in shop class is lock the trigger on on a belt sander before we put it away, in hope that the next guy who used it would just plug it in without checking. One of my shop teachers was missing 1.5 fingers from a table saw incident. Maybe he wasn't the best choice for an instructor.
 
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The safety guy at my old job only had 2 fingers on one hand. He got his hand stuck in the feed rolls on a rotary die cutter. He told the story a few times, but always left out the part that he was high as fuck when he did it.
 
   #38  

DaCat

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I get a safety call out a few times a year. Just had one 2 weeks ago. Dude put his hand into a moving machine and the rollers peeled off the skin and meat off 3 and a half fingers.

Can only imagine the mess, the machine was clean when I got there.

We'll see if the safety upgrades get accepted, quite a chunk of money to prevent people from being completely stupid. It will definitely change the functioning of the machine with lots of nuisance trips in the beginning until they get used to it.
 
   #39  
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The wife's son is a full bird manager at a big, good name grocery store. He had some dipshit employee driving the fork lift that his hand on the front roll cage. Dipshit employee mashed his hand between roll bar and the block wall, fucked it up pretty good.
They are trained to keep their hands on the controls, and not to try to be cool when driving. He did not witness the accident, but it was pretty obvious what happened by the smear on the wall.
And the staged "slip and fall" stuff he sees is pretty funny. Every aisle is recorded on video, roll back the video and watch the acting.
 
   #40  

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Back in the old tube type CRT TV days, you take the back off to replace a tube and had to make sure you didn't get lit up by a capacitor or two, even days or weeks after you'd unplugged it.
Same thing with video game monitors. One of the biggest suppliers (Electrohome) had a model (the G07) that had the HV capacitor on the wrong side of a fusible link. A blown fuse left the cap fully charged. A long shafted screwdriver with a ground wire clipped to it gave a pretty good pop. This was the cap that leveled the flyback transformer.

The focus circuit (B+) was on the HV side of the PCB. There was an adjustable potentiometer that you turned to adjust horizontal width (basically changing B+ voltage level). If you stuck a small metal screwdriver in the coil to adjust it, inductive current would shock the shit out of you. If you managed to avoid the shock (low impedance body mass), the screwdriver would get searing hot in seconds. Video game repairs aren't for wussies! A plastic screwdriver set was sold for such adjustments.
 
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