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section8 12-06-2008 04:04 PM

rd200 starter not working
Hello everyone. Im new here. I just bought my 1st bike. I got a 1975 yamaha rd 200. its awesome. The only thing not working is the electric starter. I push the button and hear a click in the voltage regulator but thats it. im wondering if the problem is in the voltage regulator. does anyone know the wiring info on these or if you own one can you look for me???please???mine has a couple wires going to a harness and a red power line going to a fuse. theres a ground right to the -terminal on battery.there are also 2 metal tabs on the side with a screw on each. the top tab has a wire under the screw but my bottom one doesnt. is that correct or is something missing.also the top screw has little tick marks on it like scars from a arcing wire touching it.does anyone know what a hot wire to the top screw would do. I dont want to try it without knowing what will happen.thanks and i apreciate any help. Erik

seruzawa 12-06-2008 05:19 PM

Make sure your battery is in good condition. Then check the wiring for loose or corroded connections. A poor battery will cause the relay to click, but the starter won't turn. Or it could simply be a bad starter or relay or corroded switch in the handle. If you can get a manual it should have a troubleshooting procedure for your specific bike.

pplassm 12-06-2008 06:52 PM

Ok. Here's my recollection on these bikes. Early two-stroke Yamahas had a starter/generator intstead of the separate alternator/starter systems that newer bikes have.

The starter/generator uses the same brushes and coil windings to generate electrical power and to start the engine. Usually, the brushes are the culprit and they are replaceable. You may have to clean the gaps on the commutator as well.

Good luck!

sachiwilson 12-07-2008 09:45 AM

Are you sure you're hearing a click in the regulator? Often when the battery is dead, the click is the starter solenoid trying to push the starter gear into place. It doesn't have enough power to do the job properly, so it just clicks.

section8 12-07-2008 09:46 AM

Thanx. I did get a manual and it explains ste starter/dynamo and how it works but no troubleshooting on why it might not work. The bike is in near perfect condition with 9000 miles so i thought that was low for wearing out brushes.that coupled with the screw tab with no wire on the regulator and the click noise is why i suspected that. i guess ill try replacing or at least looking at the brushes and i'll get back to tell ya'll how it works out. In the meantime, if anyone with the same bike stumbles across this post could you maybe see if there is a click in the regulator when you push start because the regulators job relates to after the engine is running so i wouldnt think it should click since its not part of the starting procedure.well unless there is a relay clicking in it to send power back to where it comes from, maybe through the wire i suspect should be on that screw tab?! I'll test if any current comes from that screw tab and get back to ya. oh and my shop manual has no real info on the regulator other than what it is and why. THANX so much and sorry im such a blabberhand.

mscuddy 12-07-2008 10:39 AM

I had a '68 180 twin and a 73 200 twin that suffered from starter problems due to the crank bearing on the generator/starter side being shot. The armature would rub on something inside the cases, and smoke the windings. A new crank bearing and armature cured the issues. Don't tow any B25 BSAs up a big hill or you'll be sorry....

section8 12-07-2008 12:38 PM

Thanx everyone!!! The battery is new and fully charged. the battery is staying charged running the bike with lights and blinkers on so i doubt its the brushes cuz they also do the charging but im not sure as ive only run the bike an hour or so total. mscuddy, what are b25 BSAs and are you also in the iboats forum? would your starter try to start or just nothing? i put a multimeter to the screw tab that has no wire on it and it picks up a voltage surge when i push the start button so now i really think its the regulator or part of it. I just wish there was a pic of the dang thing in the shop manual so i could rule it out. Are there any other signs of a bad crank bearing and armature? I'll probly have it looked at just in case.Is it something i could probly do with average tools? I had to become my own outboard mechanic last year after 3 motors so im getting handy with two strokes and feel more confident in my work then the few boat mechanics i let kill my motors. if anyone has an rd with electric start im still interested in what your regulator is wired like(its a metal brass looking box right behind the battery)Thank you guys sooooo much.

pplassm 12-08-2008 05:38 AM

Again, sounds like your commutator is dirty. See part number 1 here:

yamaha starter generator partsmanual fiche rd200a 1974 1975 rd200

On the outside end of that rotating mass of wire and brass (amature) are a series of brass contacts where the brushes contact the assembly. That is the commutator. Debris from the brushes accumulates in the spaces between the brass contacts, causing them to short.

Remove the stator, and clean the gaps in between the brass cotacts with a razor blade or other small piece of metal. Hopefully this will restore operation.

mscuddy 12-08-2008 08:35 AM

Good thing it's got a kickstarter! hahhahah. But seriously folks, does the battery keep a charge after your ride it around for a few days?

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