How To: Charging System Upgrade 40 Amp 3 Phase

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Low Down Chop Shop
Here is the complete How-to on a upgrade install of a Compu-Fire 40 Amp 3 Phase Charging System.

This system has SO MUCH more beef to it than the stock 40 amp system did, that the stock one would make you think it was a stock HD 32 amp!!

The other bonus to this syatem over the stock, that I think will cure many issues, is the Ground wire that runs to the battery. The Stock BDM Voltage Regulators only ground is through the mounting bracket that is mounted to the motor mount, and mounted to the frame!!

So to start this off I want to show what this system looks like and how it compares to the stock in muscle. The Compu-Fire 40 AMP 3 Phase charging system provide 25 AMPS at idle and 40 AMPS continuously above 2800 RPM and the voltage regulator output is calibrated to 14.25 volts from idle on up.

Here is a photo of the stock stator/rotor (Right) and the Compu-Fire (Left).

...and here is a photo of the size of the power/ground wires. They are about double the size of the stock ones:

So, Now on to the Install. This is a pretty easy job with standard tools and a air impact gun.

(1) We will drain the primary, and as you can see here I taped a cardboard rig up to drain and catch the leftover oil when the primary gets pulled. This is so it doesn't end up all over my lift and the floor:

(2) After draining, remove the 14 primary cover screws and remove the cover:

(3) Loosen and remove nut and the chain tensioner out from under the chain. Remove the 4 bolts holding the clutch pressure plate on (in my case with the Bandit clutch) and remove pressure plate.

Remove front drive gear nut (33mm) and clutch hub nut (30mm & reverse thread). Slide front and rear assembly, with the chain, off in one piece and put aside:

(4) Inserting the angled end in each threaded hole on the rotor, use two allen wrenches to pull the rotor off the shaft. It is magnetic, so it is difficult to get off with just your fingers.

(5) Loosen & back off the set screw holding the socket, in front of the primary. Back it out till it stops up against the inner primary cover:

(6) Remove the 4 allen screws holding the stator in. Now using a flat screw driver, push in on the plug from the outside while pulling slightly on the inner part of the plug to remove the stator:

(7) ...And remove:

(8) Now, remove the old seal seens how it has to come out to remove the factory spacer that is being replaced. I had to screw a drywall screw into mine on each side about 1/8" deep by hand, so I could get ahold of it with some vise-grips to pull it out. This seal goes in backwards, so it is a bit tough to remove.

(9) At this point, I had to do some alignment figuring and I would recommend that you do too. I measured the thickness of the stock spacer and rotor (.960) and the New Compu-fire spacer and rotor (.980). My bike at this time didn't have the .050 BDM shim behind the clutch hub (not in the 2005 bikes till near the end of the year, or dealer installed) and I was going to put that in for a clearance issue fix. So with that, I needed a .030 shim in the front to keep the chain straight. So, I tapped the new seal in and slid the spacer in place:

(10) Install the new flanged spacer from the kit with a little oil on it and the seal, so that it would be sealed up for the next step:

(11) Now, the New rotor is so much bigger and so close to not fitting that three little tabs need ground off with a Dremel or likewise. These tabs are about 1/8" wide and stick out about 1/16" in 3 spots. The rotor will not even slide on without removing them. Here are the tabs after I took the material off each. It is very little material to remove and will take you about 2 minutes to do them all. Once these are removed and the rotor is slid down inside the primary, the room opens up and there is alot of clearance at that point. BE SURE... To pack a rag or towel in the area to keep shaving out. I wrapped the seal area with tape and then used a shop vac held by the wife to suck up the shaving while grinding. That way none will get in the seal or crank bearings:

(12) Here is a fitment of the new rotor. You can see how close it is:

(13) Now pull the rotor back off and the flanged spacer. Using a bit of silicone, put some on the new wiring socket, on the rotor harness, that gets pulled up through the block. Stick the wires through the hole and using a flat screwdriver, push the socket up through until it is centered (don't pull it through the hole by the wires alone). Now snug down the set screw and install the 4 bolts (W/ Loc-tite) in the rotor and torque to recommended specs from BDM manual. Check to make sure that the stator wires are pushed all the way down inside the groove so that the rotor does not come in contact with them and short them out!!!

(14) Put your flanged spacer back in with some oil on it and CAREFULLY install the rotor without pinching your fingers:

(15) Get your clutch hub, front gear and chain assembly and put it back in place. Red loctite the threads and tighten the nuts back down to specs, install the chain tensioner to specs, and you can go ahead and install the primary cover and add fluid:

(16) Mount the Voltage Regulator in the stock location with the factory bolts and standoffs. Be sure to put a couple star washers under the VR for a good ground even though this unit has a separate ground cable that runs back to the battery unlike the factory VR:

(17) Install the 3 pins of the stator harness, in no particular order, in the socket that came with the kit and plug the stator into the VR.

(18) Route your wires under the bike just as the factory ones were and re-install the protective loom back over it:

(19) Pull the two wires up through the very small opening between the starter and trans where the factory wires came up through making sure that they are back away from the BELT!!! :

(20) Re-install the loom here also to protect the wires, snap the power wire into the fuse holder and connect the power and ground to the battery. With that said, the job should be all wrapped up.

I would recommend this on any bike, for those with the stock EHC or the Wire-Plus unit. This should will work with the factory EHC just fine and should have no affect on it, but check with your local BDM dealer.
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Low Down Chop Shop
I put a Karata open primary on my 2004 (which is the same as an 03) and it is pretty much the same as the 2005 for the most part. Actually it is the same, to say the least.
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