Regulator Rectifier all the same?

[Anonymous]

I understand how a regulator rectifier works. Converts AC to DC and maintains a constant output of 14.5 volts or so at 5000 rpm for charging. Isn't this what all regulator/Rectifiers do for motorcycles. If so, why can't we just swap one from a GS1100 and put one on a GS450 or vice versa? Maybe a little modifications to the wiring is needed. I ask this because, I'm in need of a new R/R and I can't afford a new one from Electrex. I know that Ebay has tons for sale at prices I can afford.

[focus frenzy]

the big differance is capacity, you could adapt a gs1100 R/R to a gs 450 but not the other way, at least not and have it last very long.

the regulator part works by shunting excess un-needed power from the stator to ground, that is how it regulates the output.
so if you put a regulator designed for 250 watt stator on a bike with a stator that makes 400 watts, it will over heat and fry.
there are several folks here who have done the honda 400/450 swap and the honda regulator can handle the power but has a couple extra wires to deal with.
a good idea is to use a regulator /rectifier from a KZ1100P (police) high capacity! it would take a act of god to cook one on any stock statored GS.
the problem is they are difficult to find used and very expensive new.

[Anonymous]

Ok, thanks. I didn't even think about capacity. It's starting to all make sense.

[argonsagas]

You could try this:

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=35594&item=4506655385&rd=1

or this

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=35594&item=4507149388&rd=1

or this

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=35594&item=4506741235&rd=1

Note that it is usually best if the seller says it works, as you will not likely get a guarantee of performance.

Honda units have an extra wire, as mentioned above.

On many GS series bikes, the r/r s from early 80's middle displacement engines 400/450/500 may have the same bolt fitment, so they bolt right on, although you WILL have to modify the wires and fittings.

[Keith Winter]

First off most of our bike's are all 250 watt charging systems. This is because it takes the same amount of power(in watts) to run most of our bikes. The only time the size of the bike makes any differance is if it's a big touring machine, with all the electrical options that these bikes may have. Think about it, what electrical components on a 450 are different than those on a 1100? Headlights, taillights, turn lights, are all the same. The only thing that might be any different is the ignition, and thats a very small amount, in watts. If you have a 18 pole stator, you have the same output, regardless of bike size. The big thing to look for is the wiring system in your regulator swap. On some stators the AC wires branch off and 2 wires go to the reg. This type of reg uses the same components (Zener diodes and Thyristors) as the DC reg's. The AC reg's work by "clipping" the ac sine wave peak, and shunting this peak to ground there by limiting the ac. The other type of unit works with the rectified ac and does the job by bleeding off some DC. A Zener diode for this works in it's reverse breakdown voltage. A 14 volt Zener diode will conduct, in it's reverse voltage, anything over 14 volts. If your system is putting out over this voltage to the battery, the Zenner will conduct, this turns on the thyristor, and shunts the exess voltage to ground. It's a little more complicated than this, but basically, this is how it works. Also you have to remember that when current goes down( as with a good, fully charged battery) the voltage will go up. This is why if your battery is crap, you can't get a proper read on your charging system (DC). It's interesting to note that you can go to any electronics supply store and, for about $15, buy these components and make your own regulator, and rectifier for another $20, and have them REALLY heavy duty.