Making Your Own Lighting Coil
I got this from another website:
Here is the address: http://home.comcast.net/~pgailunas/stator.html
I do not have permission to use it yet, but it's a great post.
Hi You have stumbled on my Honda Xr lighting and stator coil winding page. This page is under construction!
KA1OKQ's HONDA XR-80 & XR-100 roll your own lighting page.
Do you remember the trail bikes of the 70's? Most of the classics had a headlamp. As a kid it was a blast to take a night ride on the local trails. Well the lights have disappeared on all but the larger 250 cc and up trail bikes.
What's a kid to do? Roll your own!
I searched high and low for Do it your self lighting info for the small XR's and it doesn't exist. The vendors of " dual sport" kits are really reluctant to share any info as they are protecting there business. Hey, they gotta eat, right?...... So do I.
This page contains a step by step guide to winding your own stator coils on your XR-80 or XR-100. My bike is a 2000 XR-80.
Before you start you are going to need to acquire a few items:
A flywheel puller.
I purchase mine from Sloan's motorcycles for aprox $ 9.00
A new gasket for the flywheel cover.
I purchased mine from Sloan's motorcycles for aprox $ 5.00
1 lb of 18awg magnet wire
Mouser Electronics P/N 501-mw18h-1lb, aprox $9.00 mouser web site
A head lamp assy from the vendor of your choice.
I chose a BajaDesigns 55 W halogen unit. The folks at BAJA Designs Included some split tubing to beef up the fork tube diameter to accept the head light assy. Cost $ 88
A headlight can also be obtained from.
Dennis Kirk or from Parts Express at your local dealer. Get a halogen unit its worth the extra dough.
A regulator assy.
I bought mine from Baja Designs for $ 14.00
All factory wiring on the stator is done on terminals that are molded into the corners of the plastic stator frame overmoulding. They are electrically connected together internally in the plastic in pairs. There are spare terminals just for this purpose. Check them out with an ohm meter and you will see they are connected. All of our wiring will begin and end taking advantage of the " spare " terminals. One terminal is connected to ground.
Clean the bike. Remove the Seat side panels and Gas tank. Wash the frame down good. Dirt is your enemey.
Remove the flywheel cover / chain guard Clean the goo out of the chain guard while you have the cover off.
Use a 17 mm wrench remove the flywheel nut. I used an air impact wrench. If you don't have an impact wrench you will have to fashion a holder. Pull the flywheel. Note that the threads on the flywheel and puller are left hand thread. They are also very fine and can be easily damaged. Lube the puller with WD-40 before threading it into the flywheel. When you're done store the puller carefully. Don't let it clank around in your toolbox. You will ruin the threads and it will destroy the next flywheel you try to pull. Carefully set the flywheel aside where the magnets won't pick up metal chips. Now you have exposed the Stator Assy. You will notice that there are 5 laminated cores that do not contain coils. We will be winding our magnet wire onto these cores to "Roll our own Alternator"
4. Follow the wire harness up the frame and un plug it. There are only 2 wires. Carefully remove the harness for the clips in the frame and pull it clear of the frame.
5. Remove the Stator / Trigger coil assy from the engine. The stator / trigger coil assy is held to the engine with 2 large flat head Phillips screws. You will need a hand impact driver to loosen up these screws as they are incredibly tight. After removing them I noted that they WERE NOT loctited. Pull the stator assy from the engine and carefully remove the rubber grommet from its slot in the engine case.
Stator removed from the bike, before modification.
Follow the wire harness up the frame and un plug it. There are only 2 wires. Carefully remove the harness for the clips in the frame and pull it clear of the frame.
6. Remove the Stator / Trigger coil assy from the engine. The stator / trigger coil assy is held to the engine with 2 large flat head Phillips screws. You Will need a hand impact driver to loosen up these screws as they are incredibly tight. After removing them I noted that they WERE NOT loctited. Pull the stator assy from the engine and carefully remove the rubber grommet from its slot in the engine case.
Stator before modification
8. Lets get ready to wind the coils. Before we start, we are going to be constructing a Series Wound AC Alternator by winding magnet wire on the cores. All of the cores are wound in series. There will be no cuts in the wire. We will wind one core and move right on to the next core until we are done.
We will be winding each post with 65 turns of wire. In order to get all of the wire to fit the wire must be wound very tightly and snuggly. A sloppy job winding will result in fewer turns on the core and less output voltage.
An important note: You must note the direction that you wind the first core. Lets say you wind the first core Clock-wise when you have reached 65 turns. You will start wind the next core CCW then core 3 will be CW and core 4 CCW and core 5 the last core will be wound CW. If you wind all of the cores in the same direction it will not work.
Note It is important to count the turns properly. I marked an X with a sharpy marker on one side of the stator. Each time the X came around I would call out the Turn #. When I counted 10 turns and my helper wrote the count tally on a piece of paper.
I had my helper hold the roll of wire. It is important to get the coils tight and neat. On the first level of wrap I used a Popsicle stick to pack the coils together on the bottom of the form. The first layer sets the form for all of the layers above. If you don't get the first layer neat and tight the entire coil will be loose and sloppy.
With my helper holding the roll of magnet wire and we pulled against each other with the magnet wire tight as a piano string. The stress on the wire causes it to form around the coil form very nicely. We never let off of the pressure until the coil had 65 turns and the winding started on the next lamination.
Here is a test probe pointing at the ground terminal
9. The Existing Magneto coil obtains its ground from a terminal that has a strap leading to one of the stator fastening bolts. Conveniently there is an extra terminal for you to solder your magnet wire. If you have an ohmmeter handy you can locate this grounded terminal. This will be the start of the first coil. Magnet wire must be stripped by scraping the enamel insulation off with an exacto knife.
Here is a test probe pointing at the ground terminal
Start winding your coils and remember to alternate Clockwise / CCW from one coil to the next.
10.You have finished winding the last coil. Bring your wire over to an unused terminal and cut it to length. Scrape off the enamel and solder it into the terminal.
The stator, with the new windings. Do not use the terminals that you will need to hook your the original magneto coil.
11. Honda has tucked 2 unused pink wires inside the wire harness that exits the stator assy. If you slide the white tubing back you will find them. Pull them down and tuck them into the white tubing so that they are long enough to reach the terminal on the stator. You will want to solder both pink wires to the terminal that is electrically connected to the output end of your last coil. This is the output to the regulator and lights.
12. After you have carefully soldered the pink wires in you can reassemble the stator assy to its frame and carefully install it into the engine. Use caution every step of the way to be sure that all wiring is free and not being pinched. Tighten the flat head screws securely.
The stator, with the new windings, installed back into the bike.
13. The pink wires provided by Honda are to short to be useful at this point. I spliced on 2 feet of 20 awg red wire to these leads to lengthen them. I cut one pink wire an inch shorter than the other so that the splices would not be rubbing against each other. The goal here is to neatly splice these wires and solder them. I insulated my splices with shrink sleeve tubing. The new longer wires will slide into the black tubing with the magneto wires. I cut my lighting coil wires about 5 inches longer than the factory magneto wires. I placed some small shrink sleeve over them as they exited the factory engine harness and terminated them with a Molex 2 pin toy car connector. I used a connector here so you can disconnect the engine harness and remove the engine from the frame without cutting any wires.
14. About now you must be asking yourself “ Why are there 2 wires coming from the alternator” I used 2 wires to keep the voltage drop across the wires low. You will be pulling 55 to 75 watts (4 to 5.5 AMPS!) at 14V through these wires. You want all the power available to the bulb and not wasted as heat in the wiring.
At this point you now have your wiring up into the frame. You will join both alternator wires together on the mating Molex connector. I used 16-awg wire from the mating connector to the regulator and the lights. I picked up ground for the light and regulator at the ground bolt on the frame for the kill switch and CDI box.
The Regulator is a “ Shunt” type regulator. The regulator is connected from the alternator wire to ground. The alternator you have just built is capable of producing in excess of 48V when the engine is wound up. The halogen bulb is rated at 15V max. 48 v would easily destroy the bulb. The Shunt regulator reduces the voltage by shunting excess current not used by the headlight bulb to ground (frame). If your bulb burns out or you disconnect the bulb with a switch the shunt regulator is forced to absorb all of the energy produced by the alternator. It will get hot and eventually burn out. If you plan to switch the light off be sure the regulator is on the bulb side of the switch and not the alternator side.
It is hard to find a place to mount the regulator on the bike. I mounted my regulator inside the plastic headlight frame.
More detail to follow check back later.
COPYRIGHT (C) 2002 Peter J Gailunas 415 Fourth Range RD Pembroke NH 03275