The definitive website
for Suzuki GS
motorcycles
29 years old and counting...

The primary parts that make up the GS Charging System are the battery, the Stator and the Regulator/Rectifier(R/R). It doesn't sound that difficult a problem to deal with until your bike breaks down 300 miles from your house. Then you arrange to get it home, you ran the tests and now you need some parts.

So here we go...

Battery

The easy one to replace is the battery. These are easily obtained at any motorcycle shop, Sears, heck, even Walmart will sell them. You want to make sure that any replacement battery you get has at least the same amperage capacity as the battery you are replacing. You also want to make sure that the battery posts are the correct type. Generally motorcycle batteries have screw-type battery posts that you need, but not all do.

As for the type of batteries, there are the old-lead acid and the newer AGM (Absorbed Glass Mat) types. With the lead-acid you have to occasionally top them off with distilled water. Not a whole lot of maintenance but still something you have to take care of. The AGM batteries are sealed batteries that are maintenance-free batteries. They tend to be a bit more vibration resistant. They also tend to suffer less from "sulfation" which is the primary killer for motorcycle batteries. AGM batteries do cost a bit more than lead-acid batteries but you may find that the advantages outweigh the slight increase in cost.

Regulator/Rectifier (R/R)

The biggest change to Permanent Magnet (PM) alternators for motorcycles is the availability of Series-type v.s. Shunt-type R/R's. Most of your metric bikes have 3 phase PM Alternators (like the GS) and traditionally these have all be fitted from the factory with Shunt-type R/R's. As technology has advanced the Series-type R/R has emerged which is a night and day difference for your charging system especially as far as your stator is concerned. Less heat generated, Longer life for both stator and R/R and few burned connector. The only drawback had been price, as the after market was the only source of these retrofits. The Series-type Shindengen SH-775 has now emerged from the OEM market with a low price reflective of the mass markets.

There are really few compelling reasons in this GS day of electrical charging to buy anything other than a Series-type R/R. The SH-775 is a very affordable Series-type R/R and can be purchased cheaper than most conventional Shunt-type regulators. They are typically $70 new from Polaris dealers.

It should be mentioned that some Shunt-type regulators having been working for years, but that is generally limited to the smaller bikes that don't have the same heat problems as the bigger bikes. For anything at 1000 cc and above a Series-type R/R is a must. 750 cc is borderline I have little experience on bikes below that but there are many reports of no issues.

It has to do with heat dissipation and the Series-type R/R just doesn't create the same heat in the stator as the Shunt-type R/R will. Yes I said stator heat . Also if you plan on going to LED lights and reducing your electrical loads you will further stress the R/R.

#1 The Series-type Shindengen R/R SH-775

Commonly available from Polaris Dealers. Search the GSR site for recent posts on best price and availability. This is most peoples number one choice for an R/R replacement because of low price, easy availability and Series-type performance. It's only down size is a fairly large form factor (same as the MOSFET FH012) made even larger if you use the mating convectors.

A note from Frank: I have done some looking on E-Bay for the Shindengen R/R SH-775 and found some pretty reasonable units out there. Just make sure that you are getting the genuine article and not some Chinese knockoff.

#2 The Series-type Compufire R/R CF55402

(only part number applicable to 3 phase PM alternators like GS Suzuki)

The Compufire is my favorite as it is the smallest Series-type R/R available here in the US and is a MOSFET Series-type design which results in slightly superior performance to the SH-775 in terms of lower power dissipation, higher (low RPM) output voltage and lower OFF state current draw. General results should apply to any Series-type R/R not just the Compufire.

For additional info on R/R's please see the forum link here

Stators

There is nothing really complicated about a stator. After all it's just a big copper winding. For that you can go to your local Suzuki shop, Electrosport,com or other places on the web. You do want to be careful though about getting a used stator. It may have been overheated, damaging the insulation but where it is not visible to the eye. So be careful when buying a used stator.