This document shows how I install a new charging system; alternator, diode board and associated wiring; and the electronic ignition sensor, aka, electronic points. I show how I remove these components in this document.

• 12 BMW 1983 R80ST Remove Alternator, Diode Board & Electronic Ignition Sensor

Earlier I removed the starter motor to test it and also the crankcase breather hose. I install those at this time, but you don’t have to do that if all you are doing is replacing the charging system and/or the electronic ignition sensor.

Parts

I chose the Euro MotoElectrics Type I system which is a direct replacement for the stock BMW charging system capable of delivering 240 watts at 14.3 volts. The 1983 R80ST uses the 107 mm stator.

EME now supplies a complete charging system kit, EME Part# EDL1-ALTKIT107 that includes all the alternator parts including the stator cover with installed brushes that is NLA from BMW, wiring and a solid state voltage regulator along with mounting hardware for the diode board and stator cover and a new front crankshaft seal. The front crankshaft seal (Part# 11 14 1 255 011) is also in the EME engine gasket kit, (EME Part# GSK-EngineKit421), and I already installed it, so I have a spare one.

I decided to install the EME supplied remanufactured electronic ignition sensor, (EME part# BeanCanReMan), aka the “bean can” (BMW Part# 12 11 2 413 906), and the wiring from the electronic ignition sensor to the ignition control unit that mounts on the frame (BMW Part# 61 12 1 244 176).

I also replaced the crankcase breather hose and hose clamp.

Here is the list of parts that EME provided at no cost in support of my auctioning this bike and donating all the proceeds to the Motorcycle Relief Project.

Part #	Description	Qty
EME EDL-1 107 Alternator Kit	12 31 1 244 642 (240 watt / 17A )  Rotor 12 31 1 244 641: Stator 12 31 1 243 002: Stator Housing 12 31 2 322 417: FILLISTER-HEAD SCREW, Stator Housing 07 11 9 932 098: WAVE WASHER – B5, Stator Housing 12 31 8 002 348: FILLISTER-HEAD SCREW, Rotor Bolt 12 31 1 243 003: BRUSH HOLDER PLATE-w/ Brushes & Springs 12 31 1 244 062: Diode Board 12 32 1 244 409: Voltage Regulator 12 33 1 357 639: Wiring Set Alternator 12 32 1 243 178: Wiring Set Diode Board 61 12 1 243 224: Charging Current 12 31 1 358 130: Ground 11 14 1 255 011: SHAFT SEAL, Front Crankshaft Seal	1
61 11 1 243 646	ENGINE WIRING HARNESS, Bosch Alternator	1
61 13 1 244 464	RUBBER GROMMET, Battery (+) Cable	1
EME Battery Cable Kit	Negative ( – ) 61 12 1 244 475 Positive ( + ) 61 12 1 243 473	1
12 11 2 413 906	IGNITION SENSOR-Refurbished By EME	1
61 12 1 244 176	WIRE IGNITION COIL, ICU To Ignition Sensor	1
11 15 1 337 258	VENT HOSE, Rebreather	1
11 15 1 460 935	HOSE CLAMP – D=19, Engine Rebreather Hose	1

Tools

I use a soldering gun to solder the three stator wires to the terminals on the stator cover.

I use a oil filter wrench to help install the rotor.

Video

Here is a short video summarizing how I do this work.

VIDEO: 1983 BMW R80ST Install Alternator, Diode Board & Electronic Ignition Sensor

Install Starter Motor & Crankcase Breather Hose

I removed the starter motor to test it and fortunately it worked. You can read how I remove it here.

• 12 BMW BMW R80ST Remove And Test Starter Motor

Since the starter solenoid screw terminal connects the diode board RED DC output wire to the battery (+) battery cable, I install the starter motor. As the old adage goes, installation is the reverse of removal.

I also install a new crankcase breather hose that is next to the starter motor. I orient the hose clamp as shown so it won’t interfere with the wires that will attach to the starter solenoid and so I can get to it with a screwdriver.

Install New Stator Cover On Stator Coil

The stator cover comes complete with the brushes installed and all the terminal hardware. I need to solder the three stator phase wires to the terminals on the stator cover and attach the “Y”, or center tap, wire to the “Y” screw terminal on the stator cover before I install the stator.

I route the three stator phase wires through the hole next to the stator phase wire spade terminals. I push the wires into the slots on the tabs and then use needle nose pliers to crimp the slots so they are tight on the wires. Then I use my soldering gun and solder the wires to the slots. After I solder the wires I use wire cutters to trim the ends of the wires.

I remove the nut, split washer and spade terminal from the “Y” screw post on the stator cover. I route the “Y” wire with the ring terminal through the slot and mount it on the screw terminal. Then I add the spade terminal, the split washer and the nut and tighten the nut with an 8 mm box end wrench. I also tighten the nuts on the brush terminals at the top of the stator cover.

Install Diode Board Ground Wire

The EME kit comes with a new BROWN ground wire that attaches to the diode board. The original diode board did not have a ground wire as it did not use the rubber diode board mounts. But I install the ground wire as it’s a good idea to ensure a reliable ground to the diode board to avoid problems.

The lower mounting holes of the diode board are insulated as the metal strip along the bottom carries DC current to the output terminals and insulation keeps the metal strip from shorting out against the inner timing cover. Therefore, the BROWN ground wire has to go on the upper right mounting bolt. This is very important if your motor uses the rubber insulating mounts as the ground wire will be completely insulated from the diode board if you mount it on the lower right bolt.

I install the ring terminal on one end of the ground wire under the starter motor front mounting bolt and the other ring terminal will go on top right diode board post and be secured by the diode board mounting bolt. I cleaned the paint off all four diode board mounting posts so it will get a good ground through the posts as well.

Install Voltage Regulator Sub-Harness and Diode Board

The voltage regulator sub-harness connects to the voltage regulator mounted on the right side of the frame using a black plastic plug.

The harness includes the BROWN and BLACK wires for the alternator brushes.

There is a BLUE wire that connects to the voltage regulator so it adjusts the current flowing through the rotor coil to modulate the output of the alternator, and a BLACK wire that closes the starter solenoid sending power to the starter motor. These two wires are connected to a white plug on one end.

The back of the diode board has two sets of spade terminals: three horizontal ones in the middle and two others on the left side as shown in the picture below.

The three horizontal terminals connect to the three YELLOW stator phase wires wrapped in the white sheath. The BLUE wire in the voltage regulator sub-harness connects to either of the two terminals on the left side of the diode board.

After I attach wires to the back of the diode board, I route the YELLOW stator phase wires through the holes in the inner timing cover so they are on the right side of the engine near where they will attach to the spade terminals on the stator cover. I install the voltage regulator sub-harness grommet in the slot in the front of the inner timing cover.

I attach the diode board to the mounting posts using four Allen bolts with wave washers. I make sure the upper right bolt goes through the ring terminal of the BROWN ground wire.

Now I route the BLACK wire in the voltage regulator sub-harness through the top center hole in the inner timing cover and connect it to the spade terminal on the starter solenoid.

There is a small hole in the front of the voltage regulator sub-harness grommet. I put some silicone seal on it to keep it from allowing water to get inside the front engine cover and onto the diode board.

Install RED DC Output Wire & YELLOW “Y” Wire on Diode Board

The EME EDL1-107 kit includes a RED DC output wire that attaches to one of the two vertical spade terminals on the left side of the diode board. Each spade terminal is a different size to accommodate different size spades BMW uses for this RED wire on different model bikes.  I route the wire through the lower left hole in the inner timing cover and then over to the large screw terminal on the starter solenoid. I will install it when I install the battery (+) cable wire on the starter solenoid screw terminal.

I install the YELLOW “Y” wire on the horizontal spade terminal on the left side of the diode board. It attaches to the “Y” spade terminal on the left side of the stator cover.

Install Battery (+) Wire To Solenoid Screw Terminal

I install the battery (+) cable included in the EME battery cable kit on the large screw terminal on the starter solenoid. The battery (+) cable has a grommet that fits into the rear slot in the inner timing cover. I install the new rubber grommet over the large ring terminal. You can use dish soap, WD-40 or tire lubricant to make it easy to slide the grommet over the terminal and down the insulation. The grommet has a leg on it and it should point toward the terminal. It will become clear later why the grommet is oriented this way on the battery (+) wire.

I attach the battery (+) ring terminal on the starter solenoid screw terminal followed by the RED DC diode board output wire ring terminal, then the split washer and nut.

Since the distance from the starter solenoid screw terminal to the rear slot in the inner timing cover is short, I loop the battery (+) cable so I don’t put a sharp kink in it. This inverts the grommet which is why I installed it with the leg pointing at the ring terminal because now the leg goes inside the inner timing cover where I want it.

I tighten the nut on the starter solenoid screw terminal and then apply dielectric grease from the packet included in the EME kit.

Check Wire Routing To Avoid Rubbing on Metal Edges

I review how the wires route through the holes in the inner timing cover and rearrange them as necessary so none of them touch the edges of the holes which could chafe the insulation on them and short them.

Install New Rotor

I install the rotor on the tapered crankshaft nose. I clean the taper on the inside of the rotor and the crankshaft nose using brake cleaner and a clean blue shop towel to remove all traces of oil and grease from them. They will lock onto each other if they are absolutely clean.

I also put a bit of engine oil around the edge of the rotor that mates to the front crankshaft seal. The oil lubricates the seal and helps keep the lip from being damaged by the rotor when I install the rotor on the crankshaft.

Test Rotor Is Mating Correctly On Crankshaft Taper

To test if the tapers on the rotor and the crankshaft are clean, I tap the end of the rotor with a rubber hammer after I seat it on the crankshaft nose. Then I twist the rotor. If the tapers are clean and have mated, I can turn the engine by twisting the rotor. If the tapers are dirty, the rotor will slip on the crankshaft nose. The rotor slips, so I didn’t get it clean after all.

I cleaned both tapers with brake cleaner again, but again the rotor slipped on the crankshaft taper. So, I used metal polish on the crankshaft taper and got a lot of dirt off it. I thought I had gotten it clean, but I hadn’t. Again, I cleaned the crankshaft taper with brake cleaner and a clean blue shop towel. This time I can turn the engine with rotor, so the tapers are completely clean.

Torque Rotor Bolt

Now I install the rotor bolt with the split washer. I use the oil filter wrench to prevent the rotor from turning while I torque the bolt to 15 Ft-Lbs.

Clean Rotor Slip Rings

The copper slip rings have tarnish on them so I clean them with metal polish. I removed quite a bit of tarnish.

Install Stator and Housing

I carefully install the stator coils and the cover over the rotor so I don’t nick the insulation on the stator wires. I push up the brushes with my finger as I slide the cover and stator over the rotor slip rings. I secure the stator cover with the three Allen bolts. I tighten them in sequence to pull the stator evenly into the three shoulders on the inner timing cover. I watch the rotor as I pull it into the shoulders to be sure it is going in straight and even on all three shoulders.

Attach Wires To Terminals On Stator Cover

The rotor coil brush terminals are at the top of the stator cover. One wire is a BROWN ground wire and the other is the BLACK power wire.

The left brush terminal is not insulated and the right one is. The BROWN Ground wire goes on the uninsulated left spade and the BLACK goes on the insulated right spade terminal. The BROWN terminal has a “D-” label under it and the BLACK terminal has a “DF” label under it.

I attach the YELLOW “Y” wire to the “Y” spade terminal on the left side of the stator cover.

Then I attach the three YELLOW stator phase wires from the diode board to the three spade terminals on the right side of the stator cover. The wires can connect in any order.

I route the stator wire bundle along the edge of the stator cover so they are clear of the mating surfaces on the inner timing cover that the front engine cover butts up against so it won’t cut the wires.

Here is the installed diode board, alternator and associated wiring.

Install Electronic Ignition Sub-Harness

The electronic ignition wiring sub-harness connects the electronic ignition sensor  underneath the alternator to the ignition control unit that mounts on the right side of the frame under the gas tank. The small plug goes to the ignition sensor and the larger plug goes to the ignition control unit. The white plug connects to a white plug on the main wiring harness.

Each plug has a wire bale. In order to insert the smaller ignition sensor plug through the hole in the inner timing cover, I found it was easier if the bail was removed. I use a screwdriver to pop the bail out of the slot it fits into.

I route the ignition sensor plug through the loop in the battery (+) cable and then through the hole in the inner timing cover. I found it was easier to route it if I remove the RED DC output current wire from the diode board. Then I install the bail back onto the plug.

Install Electronic Ignition Sensor

The ignition sensor, aka the “bean can”, has an O-ring to seal the bean can in the inner timing cover so oil won’t leak into the front timing cover. I put some engine oil on it to lubricate it so it’s easier to install the bean can.

The crankshaft has a coupling with a slot and the bean can has ears that fit into the slot. I orient the bean can ears to align with the camshaft coupling slot.

The bean can wires and black cover go on the right side when mounting the bean can on the camshaft coupling. I push bean can into the hole in the inner timing cover. I rotate the bean can back and forth until I feel the ears engaging in the the camshaft coupling slot. Then I insert the Allen bolts with the large flat washer and wave washer against the head of the bolt.

NOTE:
If the bean can ears do not engage in the camshaft coupling slot, they will push on the camshaft and prevent the engine from turning. So, I ensure as I tighten the Allen bolts that I can turn the engine.

I route the bean can wire around the left side of the stator cover and connect the bean can plug to the ignition sub-harness plug. The bean can plug has ears on it so it only goes one way when mating with the ignition sub-harness plug.

Before And After

This is what I started with.

And this is the final result.

Revisions

2022-05-09  Corrected mistake about location of BROWN ground wire & updated YouTube Video.