rd charging system

sportydriver · Posted: August 9, 2005, 8:22 pm Post subject: rd charging system

Does anybody know if there are certain years that apply to the rd350 Permanent Magnet charging system. I was also wondering, I looked at the Australian site, if anybody knows how much modification has to be done. The Aussies didn't elaborate.
There is also a "battery eliminator" on E-Bay that is supposed to work on the RD type charging system. You lose the electric starter, but how hard is it to kick anyway? Anybody ever tried one of these systems?
Sporty

spickett · Posted: March 27, 2007, 6:05 pm Post subject: Re: rd charging system

Here is what I got when someone advertised on Ebay for plans to do this.
Hi Scott heres the info

A bane of the 650 is the charging system. It consists of a temporary (or electro) magnet alternator which needs external excitation to produce voltage, a mechanical voltage regulator, and a battery. The alternator's magnets are made of soft iron and are therefore only magnetic when a current is passed through them. Hence the tern "temporary or electro" magnet. The alternator has brushes which, like brake pads, wear out in doing their job. They are part of the stator and are pressed onto the slip rings of the rotor by small springs that expand as the brushes wear. When they've worn to their limit and the springs can push them no further, the brushes lose contact with the rotor and the alternator ceases to produce current at that moment. The fact that it's still turning is irrelevant.
The voltage regulator can also get out of adjustment, allowing either not enough or too much current to get to the battery. Not enough and the battery will go flat if you use more current than is being replaced. Too much and the battery can boil. Either one will leave you stranded.
Bikes that have a system like the 650 are usually medium to large street bikes with lots of lights. The alternator needs to be able to power all electrical equipment at the same time and the current required for that is way more than what's required when nothing is on. That's why bikes like that have an alternator that switches on and off as needed. Cars have a similar system. Why then is the charging system on a 650 so prone to failure when the one on your car isn't? I don't know, but fail they do.
Far too many owners of 650s wrestle with these problems but wouldn't it make more sense to eliminate them all completely?
any bikes have a permanent-magnet alternator. As the name suggests, the magnets in these babies are permanently magnetised, being made of hard steel. As such, the magnets of the rotor and stator need only be passed over each other for current to be produced. The faster the alternator turns, the more current. As the alternator cannot be switched on and off, they employ a large capacitor to dissipate excess voltage. The less electrical equipment there is in use at any time, the more voltage there is that needs to be radiated out as heat.
Some smaller bikes and particularly bikes that tend to be raced have this type of charging system. I have adapted such a system from one of these bikes onto my 650, which is the point of this story.
The alternator is from a Yamaha RD-250. The RD-350s and 400s are the same, as are the RZ-250s and 350s. However, I'm told that those delivered to the US market have a system like the xs650 so to do this, you must locate a bike that was delivered to some other market. British or Canadian bikes have the system you're after, so start there. Why Yamaha would differentiate on this is unknown. Perhaps the RDs and RZs were never raced in the US but they are (or at least were) very popular for racing in the Land down under
What does being raced have to do with it? Bikes that are raced are generally stripped of all excess weight and one thing that's not needed on a race bike is the battery. If the bike has a permanent magnet alternator, the battery can go.
To adapt an alternator off an RD onto an XS-650 requires a little work, but nothing too hard. Firstly though, you must be able to recognise one when you see it. I've never seen an RD with a temporary magnet alternator but I imagine they'd look very similar to the 650's. It could even be the exact same one. The one you want though, is inside out. That is, the rotor is external and the stator is internal. Also, being permanently magnetised, the magnets will attract a piece of steel anytime - even when the alternator is apart and sitting on a bench. So, look for an alternator that has it's rotor visible, and test it by holding a piece of steel near it's magnets. That done, see that the attached wiring is in good shape. Speaking of which, there'll be a fourth wire. It's for the ignition but you won't be needing it.
When adapting any alternator onto your 650, the critical thing is that the Morse taper on the end of the crank is the same and the RD's is. However, because the RD has a crank that's diameter is a little smaller than the 650's, the rotor won't go all the way onto the crank. Don't panic, it goes on far enough. The woodruff key is also slightly thicker on the RD and the round side has a slightly different radius. You must use the key from the RD, not the XS. Take both keys to a machine shop and tell them you want the thicker one ground to the dimensions of the thinner one, all but for 2mm along the straight edge with half the difference coming off both sides, not all of it on one side. Also, have the radius of the round side of the thicker key matched to that of the thinner. The machinist will probably do that first.
Now the rotor fits the crank, but what about fitting the stator to the case? The RD's stator is bolted to a cast plate that attaches to the crankcase. It has holes for the wiring to pass through and a couple of lugs and tangs, one of which has the ignition on it. If your 650 is to remain a 360 degree motor, it may be possible to use the RD's ignition since it's there. However, the ignitions of 2-strokes don't advance and retard. There might be some way of controlling that with a "black box" but since mine's a 270, that never entered my mind.
You need to have the stator plate machined to the correct diameter to fit in those lugs on the 650's case, and also have an area around the circumference machined flat on the backside (facing the motor). This is so the plate will sit on those machined lugs on the crankcase that once took the original stator.
Now the stator fits the case but it goes in a little too far and there's still no way of bolting it on. The 650's stator had two screws securing it to the motor but the RD has three. You'll notice the three elongated holes in the stator plate. They are of no use to you as they are nowhere near the screw holes on the 650's case. To locate the new holes in the plate, you could put the original stator over the new one and use it as to template to drill. You could also get some screws and machine the heads off and have pencil points put on. Then you wind the screws into the case with the points facing out. Place the stator plate into position and tap it onto the screws and you'll have two punch marks on the back of the plate. Before doing either one, remember to rotate the plate so that the wiring can exit through the hole to the backside of the plate and through the cut-out in the case to where the sprocket is.
Now the stator bolts to the case but it still goes on to far. To correct this, a spacer must be made. Put the rotor on the crank and take a measurement from the edge of the case to the rotor. Take the rotor off and measure from the edge of the rotor to the centre of a magnet. Add these two together. You want the centre of the stator magnets that distance from the edge of the case.
Once you have the thickness of the spacer, you can make it two ways. You can have two spacers turned up that look like wheel spacers (but much smaller) or you can make a complete ring that sits on the machined surface of the case. This is my preferred method and the easiest way is to cut that thickness off the bottom of the original stator, since you won't be needing it anymore. This must be done accurately to get the new stator to sit squarely on the case. Take it to a machine shop. I made a new LH side cover and mounted the stator to it measurement was around 5mm. Last thing to do is make some timing marks. I used the stock mark on the rotor and stamped my own marks on the LH side cover. You'd put yours on the stator plate. As mine's a 270, I also made another mark for No. 2 cylinder on the rotor.
OK, you have a permanent magnet alternator on your 650 but that's not the end of it. You can keep the battery if you like but I wanted to go without it. If you choose to keep the battery, I don't know if you need a voltage regulator or not. I imagine bikes like the RD have one, but instead off switching the alternator on and off, it instead directs current to the battery when it gets low or the capacitor when the battery is fully charged. I'm not sure about that, but it sounds logical to me. If you wish to keep the battery, then you should probably buy the entire system from the RD. It's voltage regulator probably has the rectifier built in as well.
I used a Boyer-Bransden "battery eliminator". Ask for the one for a 3-phase, permanent magnet alternator. It comes with a wiring diagram and should be fairly easy to install. I say "should be" because I didn't install mine. Not one part of the electrical system on my bike is original. Not only has the alternator been replaced and the battery removed, but I'm using a one-off Boyer ignition for a 270 degree motor. Don't bother asking them to make you one - they won't. I had to buy all the parts and have it assembled on a custom made board. If yours is a 360, a regular Boyer will work fine. If it's anything else, go for a Newtronics. Because they retain the advance/retard mechanism and so take up space in both sides of the head. I needed something that could live all by itself in the right side, as the left side is taken up by something else. As well, all the switches and lights have been replaced and the entire bike wired from scratch. I can only say that a regular Boyer ignition and their battery eliminator come with complete instructions. I said in an earlier post that my bike has full lights. What I meant was that it has a "fully functioning", albeit minimal, lighting system. She has only a headlight, a tail/brake light, a Speedo with no idiot lights, and a horn. I wanted it devoid of all electrical complexity and to have the 'minimalist" look. It was designed that way from the outset. To simply replace the 650's alternator with a PM type and change nothing else is still well worth doing. If you wish to retain all the electrical equipment (idiot lights, indicators, etc) you may still need the battery but I'd try going without it. You'll certainly need it if you retain the electric starter. At the very least, you won't have to change brushes again or risk being stranded by worn brushes or a bad regulator. If you go without the battery, you don't need to buy one, replace it every so often, check it's water, etc. You can also use the empty box as a handy storage space for waterproofs or whatever.
It's highly possible that the alternators off other bikes could be used as well. The Yamaha Zeal is one worth looking at. Being a 4-stroke, it's ignition would be more compatible with the 650. For my next project, I'll be looking at the TRX-850. There's no saying it'd fit but if it did, they have an ignition for a 270 degree motor. There are now a few of them in wrecking yards. I've been told that the alternator off a Honda CBR-250 will fit. That is, the rotor fits the crank's taper and the woodruff key is identical bit instead of being secured by a nut, it has a bolt. You'd have to have the threaded section cut off your crank and a hole drilled and tapped into the stub. That's only possible if the crank's out of the bike and - better yet - disassembled. How the stator mounts up to the case I don't know.
Is it worth all the trouble and expense? Ask yourself some questions. How much do you love your 650? Do you want to improve it? How long do you expect to keep it? How many miles do you do? Has an alternator let you down already?

If this doesn't help then you can try my aproach and that was to make my own from one out of a John Deere Tractor.

If you call Sparx electrical in England, they may have a three phase high output bolt on Unit ready to go just like the one they sell for the triumphs. they said it should be ready by the first of the year but I have not checked back since.
Good Luck

yamaman · Posted: March 28, 2007, 4:01 am Post subject: Re: rd charging system

could you repeat that please, didnt quite get it the first time! Very Happy

my race bike has a RD-RZ flywheel (with a custom stator plate) and pick up coil (needs some customising of the engine cover) , that runs into a custom black box and a RD coil. This deletes the battery and the advance mechanism. Works awesome!

beys · Posted: March 28, 2007, 12:49 pm Post subject: Re: rd charging system

Hi spickett, would you please size down your pics a bit, the thread would be much easier to follow. Thank you.

I'm running an RD alternator since 3 weeks and as far as I can see, it works perfectly.
I fitted it this winter after the original rotor was letting me down twice within two years,and it was less a big deal than spickett wrote.
I bought it from (german )ebay for about € 50,-- (~$ 70,--) complete with blackbox.

kalle from the german XS-forum sells the adapter € 15,-- (~$ 20,--) shipped in Germany
www.cokaste.de/4655/4682.html
and bolting on was much easier than at spicketts.

Note, the system I run doesn't work with the original DCI ignition, because the pick-up is in the original stator. But mine has points, as most european XS, so there is no problem.

dpmphoto · Posted: November 18, 2009, 5:01 pm Post subject: Re: rd charging system

I did the banshee swap cost me about $150 only thing i needed machined was the woodruff key,install takes about an hour and all the parts are easily obtained here in the US.

80xs650 · Posted: December 2, 2009, 12:46 pm Post subject: Re: rd charging system

dpmphoto wrote:

I did the banshee swap cost me about $150 only thing i needed machined was the woodruff key,install takes about an hour and all the parts are easily obtained here in the US.

What did the shop charge you to machine the key? Thanks.

tito650 · Posted: December 2, 2009, 7:55 pm Post subject: Re: rd charging system

i'm interested in the john deere set up .. what was the part number or make and modle that came off ? i think i found a couple but not sure .. could u maybe elaberate more on it thanks so much ! Very Happy

tito650 · Posted: December 5, 2009, 6:56 pm Post subject: Re: rd charging system

more info please .... preaty please ? Very Happy

What Happened to 650rider.com?

Yamaha xs650