Rectifier Upgrade to fix Stator Coil Issue :
All credit goes to onewizard and others who have successfully retrofitted the Polaris SH775 Series Regulator. There are plenty of texts and posts to read about the matter which can be daunting at first. Piece it all together and the upgrade is clearly beneficial. This post is however working with a Ninja 650 (2012-2016) and the location of the regulator is different. The sockets and wiring are the same however.
A little info
Stator coil seems to be the Achilles Heel in the 650 platform. The OEM Regulator is a shunt type regulator which only works in a rather inefficient way. To put it in simple words the shunt regulator keeps the stator loaded at near maximum at all times during operation. The excess current not needed by the motorcycle after subtracting electrical loads is grounded. This eventually leads to the stator shorting or burning a few poles due to aging of the insulation material due to the heat generated. Its like a dam reservoir is open 100% but only a bucketful of water is taken from the outflow and the rest is wasted downstream.
In retrospect the series regulator varies the output current by referencing the voltage across the load. The series regulator will not draw current if there is no load. If load increases it will react to the change to let in more current until the desired voltage is maintained. Therefore the series regulator is much more efficient and the benefit of this is that it does not unnecessarily load the stator coil to provide current. This results in a much more prolonged life of the stator
This is what the burned out stator will look like, a few poles blackened out.
Brand new coil from a 2016 N650, note that the coil is slightly different and there is no epoxy coat over the poles to dissipate heat better.
Before you begin
- Disconnect and remove the battery from the motorcycle and put it on a battery tender to keep it charged up.
- Tools and misc stuff needed for a neat job :
Air blower (to blow the dust away before you start taking apart the gas tank, airbox)
Sellotape (to cover the exposed throttle body, pcv tube, secondary air valve intake at top of the cylinder head cap, fuel line from dust)
Wire Strippers,
Soldering iron (solder wire, flux paste, de soldering wire etc )
Insulation tape
Heat Shrink tubing
Electrical Insulation spray
Multimeter / Voltmeter (ac/dc)
Components needed to be bought
Polaris SH775BA Series Regulator
IMPORTANT NOTE : Buying used will greatly save cost like I did buying from ebay.com, but make sure that in the product image you can see the SH775BA stamped on the rectifier itself. There are plenty of cheap chinese unbranded regualtors that look the same but will not have this part no stamped on them. Stay away from these as their construction and reliability is completely unknown. Brand new polaris rectifier is around $160 [ part no : REGULATOR-3PH,35A,SERIES,105C (4012941)]
New Stator Coil for the 650 OEM recommended.
The OEM stator is a delta wound stator with much more copper against the aftermarket replacements which use a Y winding pattern to save on copper costs.
Triumph Link Lead
This can be ordered from
T2500676 Triumph Link Lead, Regulator $10.00 - 2WheelPros , they also ship internationally partnered with a shipping service.
Stator Cover Gasket
Since Kawasaki India pretty much sucks hardcore, they did not have a single gasket in the entire country in stock. So I made my own with laser cutting done on gasket material. The stock gasket is a graphite coated reusable gasket so if you pry off the gasket carefully you will not need a new one. Mine was damaged in removal so needed a new one. This gasket material is normal and not reusable.
I am not covering the stator installation and testing as its completely shown in the workshop manual, along with the ac voltage check across the three pin socket coming from the stator itself.
POLARIS RECTIFIER UPGRADE
On the ninja 650 the rectifier is located in the middle of the chassis directly below the steering lock.
To get to this you will need to remove the gas tank, the airbox, the secondary air valve.
Before you remove the airbox use the blower to blow away any loose dust as the throttle body will be exposed to unwanted matter.
After the airbox is removed, use sellotape to cover the throttle body ports, as well as the tubes connected to the engine and also the secondary air valve intake port on the cylinder head. Also cover the fuel line. I also removed the ECU to avoid dangling it on the side, also covered the ecu socket with sellotape.
After the secondary air valve is removed, it is possible to take out the rectifier. You have two 10mm bolts to loosen to remove the rectifier. There is a clip on each bolt to keep the wiring above the rectifier tidy and in place. Do not forget to install these back during reassembly.
Now remove the stock regulator from the socket, and then cut the female socket on the wiring harness to an approximate length below. This length will allow you to go stock if you want to sell the motorcycle.
Then take the triumph link lead and cut these two connectors off. The postive and negative dc lead each split into two wires which we dont need.
CONNECTING THE NEW SOCKETS
Before joining the wire slide the heat shrink tubes over each wire and push them away as far as possible from the point of wire join as solder heat can cause the heat shrink to.. shrink.
To join the wires I joined them interwoven and soldered them (inline wire splice), then wrapped in electrical tape and then the heat shrink was moved over (shrunk later after testing), the wires from each side had about an inch and half of exposed wire so that the solder and connection is strong enough. While joining the wires please keep some sort of metal sheet below the work area to avoid dropping solder on the motorcycle components. Also make sure to wear safety eyewear and not breath in the solder fumes.
Now take the triumph lead socket with three pins and connect the three black wires to the exposed black three wires from the wiring harness, order is not important.
Then take the other two pin socket of the triumph lead and join the brown wire from the lead to the white wire from the regulator. Both the white wires from the wiring harness end up as one so its okay to join them as one. The black ground of the socket goes to the yellow black wire from the bike.
This is what the new socket setup looks like. I then wrapped all the five wires with an eletrical insulation tape to keep the wires tidy.
Spray the female sockets with an hydrophobic insulation spray like this. Then couple them to the newly installed rectifier.
Now connect the polaris rectifier and install it back. This regulator causes a bit of a problem to slide back due to size of the sockets getting obstructed in the little space in the chassis. Move the rectifier in gently and dont damage the connectors while doing so. Here's what I mean.
After putting back everything together, reinstalling the battery, voila, Success ! 14V on my onboard voltmeter !