Topic: Any Electrical gurus out there? stator problem

[CrAiGzEE]

Hi All,

some how inbetween trying to get my cb466f on road a mate has dropped his CT125 asking me to convert it to 12v. I have done plenty in my time and this one has turned into bigger than Ben Hur. normally i just convert it to a full wave and add a pitbike regulator.

I tried to use the standard magneto/stator setup but had no luck due to the complicated stator setup. so I thought Id start from square 1, I purchased a Chinese 125 ATV stator off ebay for 10 bux and fabricated up a plate so it would bolt to the standard housing.

Reassembled filled with oil and gave it a kick, no spark. Pulled out multi-meter and measure the voltage as I kicked it, was getting about 60v out it, So I thought yah it works.

Now after hours and hours of research I seem to have got no where. some of my theory are as follows.

The CT125 uses what i understand to be an inductive ignition system, The Other uses a Capacitor discharge ignition. And now presume that there is a difference in potential difference between the two. So I thought that maybe this new set up does not generate enough voltage to intern allow the coil to fire, so I ran the coil directly off the 12v battery and what do you know it fires. so there goes that theory. Can anyone explain a concept i am missing.

Ill put up a copy of the wiring diagram and if someone could explain the way the stator works that would be greatly appreciate it. I'm going round and round in circles and basically going mad with frustration

thanks in advance

[b52bombardier1]

My guess is that your year of the CT125 uses the same kind of ignition that is in the six volt CT90, ST90 and CL100 bikes - battery power to the ignition coil.  Then the stator power goes through a full wave bridge rectifier such as the modern silicon DigiKey part number GBPC2504-E4/51GI-ND rectifier to recharge the battery - replaces the inefficient original Honda selenium rectifier. Note that there is no voltage regulator on these older Honda rides.  The battery and the wattage consumed by the bike's lighting keeps the voltage from going too high and boiling the battery electrolyte - a "balanced" voltage regulator, by another name.

  I have no idea how your new stator is constructed or wound but the output of the original stator and permanent magnet setup in the flywheel was rather meager in terms of wattage output.  The day those permanent magnets in the CT90 flywheel left the factory back in the 70's was the strongest they'd ever be and only made 62 watts at 5000-6000 RPM . . . not a lot of power. And a good bit of that is wasted as heat in the rectifier. So I'm always perplexed when people want to "upgrade" (?) to 12 volts.  I have plenty of good luck leaving my bikes at six volts though I usually have to work on achieving clean electrical system grounds, repairing dodgy connectors and getting rid of that toxic selenium rectifier.

And what twelve volt appliance or lead-acid battery can stand the wildly varying system voltage (with change in RPM) on these bikes anyway?  Two years life span on a battery is about all I get and there's just not enough capacity or regulation to safely run even a cell phone charger.

Rick

[strynboen]

i have  used a atv stator ..and rotor ..on my Yamaha fs1..it vorks just fine..only prob vas the pick up vho is autside the.rotor trigged by a magenet..just take all parts  and mowe over even the flyvheel..took the konic part of the flyvheel and moved it over in the atv part..goit tons of power and stabiliced 12 volt and cdi ignision ...all the best..but easyer to find a Ducati/scooter/derbi senta system..vho have cdi pick up sensor inside the flyvheel..it make montage easyer..an is a low cost system