Kokusan Electrics on 1977 GS550

[Druff]

I have a 77 GS550 and was planning to upgrade the Rectifier, Stator, possible ignition and coils...

Electrosport (and everywhere else) suggests 12 pole Stator and matching rectifier BUT when I removed the covers the Stator has a Kokusan Rotor and an 18 Pole Stator... Kokusan Ignition/points too.

Is this common and do I need a different Rectifier than the suggest for a 77GS550?

Any thoughts or input welcome. D

[koolaid_kid]

First, welcome to GSR.
Second, while I can't answer the ignition question, the 18 pole stator and rotor is a good upgrade. Since this mod has been done, I suggest checking out your regulator and rectifier. It may have been swapped out for a combination Regulator/Rectifier already, another good upgrade.
You will need to follow the wiring trail from your stator to your rectifier, or regulator/rectifier, as the case may be.

[tom203]

Some PO upgraded to 18 pole stator- be happy, it has slightly more voltage at low rpms. Why don't you test the charging system before buying stuff? here's a quickee test, report your results and you'll get honest advice

http://members.dslextreme.com/users/storagecliff/images/electrical_odd-n-ends.html#A20

Do you have a seperate rectifier and regulator or was that upgraded to combo unit?

[Druff]

It was bad, bike ran for 30-45 mins once hot it shut down, battery was dead. Its been torn down to the frame for a complete rebuild-redesign. Ive rewired the whole bike and removed alot of excess wiring (like the lovely white-green and white-red that I spent a day n half chasing). So I figured replace them and have a much better running motor. Seems the Kokusan set up was 'stock' on some 77 versions but uses the same rotor, stator etc from an 80 L/M version... been chasing my tail trying to figure it out. I just need to make sure I get the right R/R, I cant seem to find out the difference between the ESR100 or the ESR090... same output so whats the difference?

[Steve]

It's nice that your stator has been upgraded to an 18-pole, but you need to also verify that the rotor has been upgraded. The easiest way is to simply check the output voltage of the stator. If you are getting 70-90 volts with the engine at 5000 RPM, you have the correct rotor. If you are getting very LOW numbers (maybe 10-20 volts) you still have the older 12-pole rotor.

If that is the case, you need to change your rotor before changing anything else.

.

[Druff]

Rotor has 6 pairs of magnets (I checked with the ole magnet test) which I believe is for an 18 pole stator?

[Guest]

There is no particular "right" model R/R for your bike as long as it is a 35A three phase R/R. The one of choice today is the Shindengen SH-775 series R/R that goes under the alias of a Polaris part number 35A 3PH Series Regulator 105C 4012941 found on a 2011 Polaris R11HR76AG/AR Ranger 6X6 800 EF.