1994 Honda XR650L

Here's another one of my bikes. It's a '94 Honda XR650L.  I had always had a low opinion of these beasts until I decided I wanted one.  My '99 Yamaha WR400 was taking a beating on the long adventure rides we do from time to time with Dixie Dual Sport.  I needed something that was dirt worthy but could handle extended miles on pavement and not need so much maintenance.

The picture above was taken right before I bought it.  I got the bike used on December 30, 2007 with 9400 miles on it and I was instantly disappointed in the power it had.  The thing was a complete dog.  It needed work.  At this point in mid-summer 2008, it still does.  But the changes I've made have had an enormous difference in it's fuel economy, range, rideability, comfort and practicality.  The bike was a mess.  From a distance it looked clean.  Up close there was years of gunk built up in places and it took powerful cleaning solvents to make it shine.  But it shines now.

My first ride on it took me through the Ocala National Forest where I almost ran out of gas at 60 miles on the trip odometer.  I got lucky and some quad riders gave me some gas and it was enough to get me to a station.  I averaged just over 30 mpg.  The bike hits reserve at 2 gallons with 0.6 left so at 30 mpg, that doesn't leave much room for error.
New tank- check.
Chain and sprockets were shot.  New set- check.
Tires were bald.  New set- check.
The stock handlebars sit in your lap.  New bars - check.
The forks were pretty floppy.  Fork stabilizer- check.
Footpegs were like little nubs.  New footpegs- check.

I read up on Thumpertalk about something called "Dave's Mods".  To try to get some more power out of it, you modify the fuel screw so it's adjustable, re-jet and drill the slide.  It was marginally better.  What's really helped was opening up the airbox.  I took out the snorkel and used a utility knife to remove pretty much the whole top of the airbox.  Ran much better, but fuel economy was still crap and it had, well, let's call them "issues".  At full throttle in fifth gear it would start bucking and cutting out.  No jet changes seemed to help.  I just resigned myself to living with it and use the bigger tank to make up for inadequacies.  We men are good at that.

By the time I posted this, it has almost 11,500 miles on the odo- just over 2000 mile since January 1.  I have changed the oil twice, replaced the fork oil and put on Seal Savers to replace the deteriorated fork boots, and got the mods above. 

Just last week, I did the best thing I could have done to make the bike more rideable and fun..  I replaced the stock carb with a Keihin FCR 39 flatslide pumper carb.  Jetting was almost identical to the jetting it came with as a stock WR400 carb. DTM needle, 42 pilot and 150 main.  The thing flat out hauls now.  No flat spots or bucking.  It just accelerates from bottom to top cleanly in each gear and without issue.  Idle is much smoother and it starts like a charm.  To top that off, it now gets 41 mpg.  With the 4.7 gallon Clarke tank, that's 189 miles max range.  Pretty good for a dirt bike.

To make the bike more practical, I added a rear cargo rack and a top box.  For those long adventure rides (and commuting) this luggage is indispensable.

Now, what's left to do?  Top end and timing chain/tensioner.  I'll be replacing the rings and valve guide seals to maybe get a bit more compression and maybe use a little less oil.  The engine rattles coming off the throttle and it sounds like a loose cam chain to me.  That should be it if I'm lucky.  After that, it should be a reliable steed with many years of service ahead of it.  Even though it's already 15 years old.

Here it is, ready to go anyhwere:

Chompin' at the bit...

Looks fast, doesn't it?

View from the back:

This will make life on the road much easier.  I attached the box to the rack using 4 U-bolts.  It's on there solid.

.

Dual-Sport FAQ's

Keith writes:
I read your article and seen your bike on Thumper Talk, and let me just say I am very impressed on your electronics knowlege and how to apply it. You take something that I always looked at as being very complicated, and explain it in a way that it is actually pretty simple.....Anyway I just bought a 1983 XL600R which is in pretty bad shape. The wiring harness was completely hacked up and nothing, as far as the lighting system worked. I have since pretty much rewired the bike and have everything working except for the blinkers. Actually they do come on but I cant get them to blink. And when I do turn the switch on (doesnt matter right or left) the tail light light goes very dim. I have tried replacing the flasher unit and have double checked my ground routing etc. I am kinda stumped and was wondering if someone with your knowledge could point me in the right direction.   I Thank you very much for your time ,  and any input would be greatly appreciated.    Keith.....

My answer:
Keith,
The blinkers not blinking problem is simple.  You are not getting enough voltage through the flasher unit to get it to flash.  The units require a minimum voltage to start flashing.  Try revving the motor with the flashers on to see if it makes the flashers flash.  If you have a 12 volt battery, tie that in and see if the extra voltage makes it flash.
 
Unfortunately, the flasher problem sounds like the symptom of improperly connected wiring or worse, a bad generator.  You will first need to check the resistance across the generator coils.  .  If you have a manual, it should tell you what the normal resistance range across the coil is for your bike.  If the resistance is too high then you probably have a broken wire, if it’s too low it’s possibly shorting.  If the stator is still good, that’s good news because you just have it wired wrong or a bad connection or a bad battery.  I know you checked the wires but obviously something is wrong. If the bike has a battery, make sure the polarity of the current from the generator is correct. If it’s not, it will work right sometimes but it will do weird things other times. 
 
 If you do have a battery, then all of the ground wires for lights, horn, etc., should be connected ultimately to the negative terminal of the battery.  They should not ground to the frame. 
See if the battery is still good.  A bad battery will also wreak havoc and cause strange behavior.
The switch may also be the culprit.  If it (or any of the connections) is corroded, it will cause a power drain.
Good luck,
Rich

---

Brett writes:

Hi Rich, sorry to bother you but im still stuck ill send you a picture of my exact wiring diagram (stock australian) and where i may think there is a problem and where i have spliced. hopefully your bikes wiring will have been the same. when i wire it this way, nothing happens. and it seems to short the battery i think. i have all the parts needed, just stuck at this point. i would like to keep the original harness if possible. can you identify my problem? thanks so much for your time ps. feel free to use this on your sites FAQ if need be http://gallery.oldholden.com/Brettv/wrf-wiring+comments.JPG.html

Alright Brett, here's the deal:

Looking at the wiring diagram you sent, I can see why you are having problems. But we can fix it. It looks like the bike is just lacking a battery and that's what you are wanting to add to the bike.

Let's figure out what's going on before we change anything. Take a look at the diagram at the area between the YLB plug and the voltage regulator (where you did the splicing.) The yellow (Y) wire supplies the main power to the wiring harness. It goes up to the switch unit and the switch and switched power is returned through the blue (L) wire. The black (B) wire provides a common ground for the electrics.

You were on the right track but not quite all the way there with your splicing. First, you will not be splicing. You will be cutting. Cut the yellow wire after the point at which it ties in to the voltage regulator (VR). Let's call this "Cut #1". Solder the side of that wire closest to the VR to one of the AC terminals on the rectifier. Cut the black wire between the point at which it comes off of the VR, past the point at which it's grounded to the frame but before it starts to go to the rest of the wiring harness (still in the gray shaded are on the diagram.) Call this "Cut #2". Solder the side of that wire closest to the VR to the other AC terminal on the rectifier. You now have DC current available but it needs to be connected to the battery and back into the wiring harness.

Now solder a wire to the DC (+) terminal of the rectifier and then make a split off of that like on http://www.farplaces.com/wiringharnessfab.htm. One of the wires will join back to the free yellow wire you cut earlier at Cut #1. The other will connect to the (+) terminal of the battery. Solder a split wire to the DC (-) terminal of the rectifier and connect one of the wires back to the free end of the black wire in the wiring harness at Cut #2 and one to the DC(-) terminal of the battery.

(Make sure none of the black wires past the rectifier are still connected to the frame ground. The wiring diagram show the black wire splitting off past the VR and going to the front and back. You may need to make another split off the DC(-) to connect to the front and back wiring harness grounds.)

Don't forget to put in a fuse inline with the DC(+) line somewhere after the battery.

My crude drawing may help:


Joseph writes:

Hello there. Good article on dual sport setup much obliged. Quick 
question, what battery did you use and what are its dimensions?
thanks
 
Joseph
      

Joseph,

It looks like the battery here:
http://www.electronicpartsforless.com/storefrontprofiles/processfeed.aspx?sfid=100806&i=51406608&mpid=36&dfid=1


There are all kinds of brand names out there for this type, I use 
whatever the local battery store carries that's cheapest.

Lucas wrote:

I have just purchased a WR400 that is going to be converted into a supermoto bike. 

I had a question regarding the wiring of the relay in the second diagram.

My answer:

The relay switches on the current to the wiring harness when the engine is running, so you don't accidentally leave your lights on after shutting off the bike. It breaks the circuit from the battery to the rest of the wiring harness. So if you have a battery for the lighting circuit and you are concerned that might happen, the wiring diagram you are looking at will fix the problem.

The "detection" side of the relay is wired in between the rectifier and the battery. So connect one side of the detection circuit to the hot (+) wire in between the battery and rectifier. Then do the same thing for the ground (-) wire between the two. You see the diode? That's to make sure the switch isn't activated by the battery itself and it has to be wired in the proper direction as I indicate in the drawing. The switch side of the relay is wired in anywhere after the fuse on the hot wire. Polarity is unimportant for either side. If the relay has polarity markings however, follow the markings directions.

Installing a Radiator Fan

I did this as an experiment and so far it's working.  Sometimes when I'm running my bike in very slow tight terrain or sitting in traffic (this is very rare but it happens), I can hear the coolant boiling.  This isn't a big problem with a WR400 because it has a coolant reservoir that captures the overflow.  When the bike cools off, the coolant is drawn back into the radiator as needed.  But, I like to tinker and I thought it would be nice to have a fan to see how it works.

I went to Skycraft and bought a 12 volt, 0.6 amp brushless muffin fan.  Something like this would also work well.  It is wired into the main electrical wire before the main switch, so it can run whether or not the lighting circuit has been switched on.  I used safety wires to tie the fan onto the radiator through the tubes and fins on the front of the left radiator.  It is attached directly to the radiator.  The Devol guards protect the fan nicely. 
In the first version of my fan install, I safety wired the fan to the guards themselves but I didn't get as much airflow through the radiators with the fan on as I would have liked.  With the fan directly mounted to the radiator, the fan makes much more of a breeze through the radiator.

I haven't used the fan very often, but like I said, it does make a pretty good breeze blow through the radiator.  Also, I am pleased with the fan's resistance to water so far.  I have washed the bike quite a few times with the fan installed and have been through some very deep puddles.  So far, it's working like a champ.  One time I got some vegetation stuck in the fan and it didn't want to spin.  I cleaned it out and it began working properly again.

Here are the handlebar switches:

Picture of the fan close up:

Picture of the whole radiator:

Fabricating a Wiring Harness

Alright, you've got this far and you actually want to make your own wiring harness.  It's not hard, it just takes patience.  If you aren't already skilled at soldering and crimping, you will be by the end of this.  There's no place for twisting and taping in a dirt bike wiring harness.

What we will cover on this page is how to actually make the connections: tips on how to join the wires and what to look out for.

First thing, you must plan ahead.  Create or borrow a wiring diagram, like I have on my dual sport page.  You have to know where everything is going before you start.  Then you have to decide the routing you will use so you can figure out how long the wire needs to be.  I used a 7-conductor wire as the backbone of my wiring harness.  You can use individual wires but make sure they are well protected so they don't get chafed.  Once you figure out how long the basic harness needs to be, cut it about 2 feet longer than that.  That will give you a foot on each end to work with.

Starting
The way to do it is to start at the front and work your way to the back, all the time trying to position the wires so that you can use shrink wrap.  The only tape will be on the final outer coating at the cruxes (the places where the harness splits to go to the components.)  You want to cut the wires just long enough to do the job but not too short.  You are trying to minimize the amount of wires so they will all fit under the headlight shroud and under the seat.

Butt Splices
Lets look at the basic butt splice.  The butt splice will allow you to make precise cuts-to-length.

Start with two wires coming from opposite directions

Cut them at the same place.

Now they are the correct length for the job

Strip both ends about 1/4 inch

Don't forget the heat shrink

Solder the joint using a butt splice

Heat the wrap to button it up

See, that was easy.  You will do a lot of these making the harness.  Just be sure to stagger the position of the butt splices.  In other words, don't make all the initial cuts like in the second picture at the exact same location on every set of wires.  That would create a large bulge in the wiring harness at that point.  Stagger them a little so you only have one or two butt splices at any given point in the harness.

Junctions: Joins and Splits
Ok, now we're going to get fancy using something called a ferrule.  A ferrule is a little split cylinder of metal that you crimp over two or more wires to join them together.  This allows you to make neat clean wire junctions to make one wire split into two or join two into one.  Here's the basic technique:

Start with 2 wires

Strip one using a sharp razor blade (careful!)

Slide a ferrule over the wires and crimp

Solder for extra security

Heat shrink over the join/split

Now you have a split or join

These are very useful in tying in components to common hot or ground wires.  In this example, if the white wire was a common switched hot wire, you can tie in each component along the white using the same technique all along the wire.  This type of connection make the harness much less bulky than if you try to join them all together at one point.

Zipping it all up
The reason you start at one end and work your way down is so you always have an end to slide the heat shrink tubing from. It's kind of like one of those childhood games where you have to slide tiles around and only have one free space to move in. Always have a place to slide the heat shrink tubing to while you are soldering so it doesn't shrink prematurely.   Also, I like to reinforce the large split points (for example, where all the wires split off to go the the turn signals, horn and lights) with zip ties.  This helps keep everything together and strengthens it.  After you do all that, make a final wrap with electrical tape to protect the few exposed wires at the junctions.

Dual-Sporting an Off-Road Bike

There's a lot of talk these days about making an off-road bike, such as a Yamaha WR426 or a Honda XR400, into a street legal machine.  There are many ways to do this.  One way is to buy a ready-made kit.  I've gone this route and have been unhappy with the cost, quality and durability of the components.  Another way is to do it yourself.  That's what this page is all about.

First things first.  Nothing you do here is going to change the emissions of the bike to make it meet EPA emissions requirements.  If you have a bike built by a large manufacturer, then in order for them to sell the bikes for on-road purposes, they must meet certain emissions standards.  If you are reading this, then your bike probably doesn't meet the standards.  But these requirements only apply to manufacturers.  The EPA doesn't regulate the end user in this regard.

Which leads us to the next topic: state requirements.  No matter what the EPA says, in order to get a license plate for your off-road bike, your state has to sell you one.  Different states have different requirements.  You may or may not be able to get a tag for your bike in your state no matter how street-legal the lights are.  But don't give up hope.  If you are creative and persistent, there may be a way to do it.  Some states restrict these bikes by VIN.  These are the hardest states to get a tag in.  Some states just want your money and don't care what the bike looked like before you put lights on it.  Talk to people in your local area for advice in getting a tag in your state.





We've talked about the legal stuff and now you just want to make your bike have lights so you can get a license plate so you can connect trails without having to worry about getting fined.  This page assumes that your bike at least has a lighting coil already on the bike and possibly a head and tail light.  If you have an MX bike, you are going to have to spend some money and get your stator rewound or get a new stator with a lighting coil.  I am also assuming that you have the ability to solder and use heat shrink.  Don't twist and tape these connections. 

Let's start with a shopping list:

• 18  ga wire (red)
• 18 ga wire (yellow)
• 18 ga wire (black)
• 18 ga wire (blue)
• 18 ga wire (green)
• 18 ga wire (brown)
• 12 volt sealed-lead acid battery, 1.3 amp-hour capacity.  Looks like this:

• Blue LED (High Beam indicator)
• White LED (Tag Light)
• Solder
• Heat shrink in various sizes
• 2- 330 ohm resistors (for LEDs)
• 35 amp 200-volt rectifier
• Heat sink for rectifier
• 4 turn signals
• 2 3-way switches (one for the high/lo beam and one for the turn signals)
• 2 brake light switches.  The rear brake switch can be either a pressure switch that replaces the banjo bolt or a pull switch that mounts to the frame.  The front brake switch should be a pressure switch.
• 12 volt 2-prong automotive turn signal flasher unit
• 12 volt motorcycle horn
• Extra kill switch (will become horn switch)

Now you've got everything you need to make a basic kit.  If you want to go one step further and make the system really look good, you need a real handlebar switch set.  I got a switch set off of an '04 GSX-R 600 off of eBay and it really works nicely.  It replaces the three way switches, the extra kill switch and even the main switch (which I am also assuming the bike has if it has a lighting system already on it.)  These switches can be found new on the internet.  Just don't get one of these:
 
They suck.

Here's a picture of my switch set:


In order to meet most state requirements and to power all of your accessories, you will also want to put a battery in the bike for the lighting circuit.  This will necessitate rectifying the current.  This will also make your headlights brighter and not dependent on engine rpm to keep it bright.  We'll get into all that below.



The first thing you need to know is how you are going to connect everything.  I have put together 3 different wiring diagrams.  The first one is a basic diagram that will do everything you need. You can turn the lights on and off with or without the motor running.  The second is an advanced system that will automatically shut off the lights when the motor stops running.  This is helpful if you don't want to leave the lights on and kill the battery when you shut the bike off but leave the lights running.  The third is an override that allows you to turn the lights on when the motor is off (like the basic diagram) with an auxiliary switch.  I use this for lighting system troubleshooting and if I need the lights on if the motor is off.  Other wise I keep that switch in the off position.
Here are the links to the three wiring diagrams in pdf format.  Read below for more detail on how to use them.
Basic Wiring Diagram
Wiring Diagram with Auto-Shutoff Option
Wiring Diagram With Auto-Shutoff and Bypass Switch
 
Let's Start With the Generator
The generator makes electricity for your bike to make a spark and to power the lights.  These are separate circuits and they are both alternating current.  The bike is wired to use the frame as a ground (common) and the two separate circuits go to various places through the stock wring harness.  We will not mess with the spark circuit.  But we will mess with the lighting circuit.
 
Voltage Regulators
To keep from blowing lights and killing your battery and other components, you will need a voltage regulator (VR).  If you have a bike that comes stock with lights, it already has one.  This is how it works: AC voltage comes from the generator and varies depending on engine rpm.  The VR is wired in parallel with the power and is grounded to the frame.  As the voltage exceeds the desired value, the VR "bleeds off" extra voltage to the frame ground and gets hot.  (Touch your VR during a ride and see for yourself.  Careful!)  This is why VRs usually have some kind of heat sink built in or are out in the air flow- to cool them. 
There will be 2 wires coming out of the VR.  One comes from the generator and the other send current on its merry way to the lights.  The VR is bolted to the frame and grounds itself that way so it can bleed off the undesirable high voltage.

I think this is why so many aftermarket VRs die so young.  They don't ground to the frame and have no heat dissipation capability.  I killed 2 in a short time from this issue.  Stick with the stock VR if you can.
 
The Rectification of the Voldrani
Ok, I know that's a nerdy reference to Ghostbusters but now we are going to think about the rectifier.  If you want a battery, LEDs, a regular horn and to have your lights on without the motor running, you will need a battery.  One problem: batteries make direct current (DC).  Your bike makes AC.  How do we rectify the situation?  (Pun intended.)  With a rectifier.  Go to this link to read more about it from people who know way more about the subject than I ever will.

A rectifier is an electronic device that converts AC to DC.  It uses a bunch of diodes (little electronic "gates" that allow current to flow in only one direction) in a cleverly arranged configuration to do this.  You can get them at Radio Shack but you can also get them from Skycraft.  They are cheap and small and can handle up to 35 amps and up to 200 volts.
Here's a picture of one.  They're about an inch long on each side.


You will have one wire coming from the VR, which is AC.  Connect this to one of the AC terminals on the rectifier.  Now find a good place to connect a ground wire to the frame.  The place where the VR is connected to the frame would be a good spot.  Take that wire and connect it to the other AC terminal on the rectifier.  The rectifier will have (+) and (-) terminals.  These are the DC current positive and negative terminals which will provide power for all the lights and accessories on the bike and will be connected to the battery.
A note about the rectifier capacity:  Your bike makes at the most 15 amps of current unless the stator has been rewound.  So why do we need a 35 amp rectifier?  Better to have the capacity and not need it than to need the capacity and not have it.  The larger the capacity, the cooler they will operate.  I use a heat sink on my rectifier just to be safe.

The Battery
Now that you have regulated DC current to play with, all you need now is a battery.  I don't know why everyone is so keen on "battery eliminators" and NiCad batteries.  The battery I show above is small and inexpensive (less that $20) and is a real sealed lead-acid battery.  They can charge and discharge just like a car battery.  NiCads don't handle these repeated cyclings very well, in my opinion.  And how much juice can you get out of a battery eliminator. Go with a real automotive type battery.

The two wires coming from the rectifier connect directly to the battery- (+) to (+) and (-) to (-).  Then run another wire from the battery terminals to the lights.  The lights will run off the battery and the generator will charge it as it drains.  Use red wires for (+) and black wires for (-).

Here's the battery, rectifier, and relay switch in the air box.  The black wires are the AC power and the two red wires are DC (+) and (-).  The green wires are for the rectifier switch cutoff.


Taking Stock
Let's take stock of what we have done (and spent) so far:

• Connected the voltage-regulated current to the rectifier
• Connected the rectified current to the battery.

How much have we spent:

• Rectifer- $3.50
• Battery- $20.00
• Wires and solder- maybe $1

If this would have been a dual-sport kit, it would be $100 so far, at least.  See, you're saving money and you know how it works!

Wiring Harness From Scratch
Now that we have power, we must distribute it around the bike.  Here's where the shopping list and the wiring diagram comes in.  We need to get power from the battery to the front and rear of the bike and to a central switch unit.  I installed my battery, relay switch, and rectifier in the air box.  They fit nicely in there, they are protected from damage, and are in a central location that is easily accessible.
One way to do it is to run wires everywhere and hope for the best. A better way to do it is to make a wiring harness.  You see the first items on the shopping list is a bunch of 18 gauge wires in a bunch of different colors.  Here's how they will be used in the main wiring harness:

• 2 red wires coming off the hot (+) side which will go to the main switch and back. 
• 1 Black for the ground. 
• 1 Blue wire coming from the front brake switch
• 1 Green wire for the left turn signal
• 1 Brown for the right turn signal
• If you plan to power a GPS or some other accessory, you'll need one more wire in the harness for that
• If you want to install the auxiliary lighting switch to bypass the relay, you will need a wire for that.

You can bundle all these up and wrap them in a spiral or split loom wire wrap, or you can tape them up (not recommended) or, you can get wire already bundled with a heavy-duty outside insulator to protect against abrasion.  Skycraft sells all sorts of bundled wires.  You might have to call them because I don't think they sell 6, 7 or 8 conductor wire online.  However you decide to do it, you need about 4 ft of wire to go from the battery to the handlebars and have enough left over to work with.

7-Conductor Wire

You will use the other colors of wires and additional single strands of wires to make the connections to the individual components.  Whatever you do, make sure everything is soldered and heat-shrinked for insulation and durability. I have learned this from experience.  Click here for more on making wiring harness connections.
Route the wiring harness under the backbone of the frame, over the carb and up into the air box.  (I have mine routed in between the upper engine mounting brackets.)  The front of the harness can be routed under the VR and will come out behind the headlight shroud.

Front wiring harness

Rear wire routing

Rear wiring harness

Neatly tuck in all wires

Whichever way you decide to go, it shouldn't cost you more than $10 for all the wires.  Of course, you may decide to buy more wires than you need to have as extras.  I bought 80 feet of good 18 gauge wire at Skycraft for $4.  The total length of wire you will use will not exceed 50 feet.

Compare this with the cost of my dual sport kit.  The kit cost $400 in 2001.  All I have left from the original kit is a wiring harness and 2 turn signals.  Everything else has broke or died and not from crashing or abuse.  That's one expensive wiring harness!

Tag Light (that's a BRIGHT white LED from Radio Shack):

Turn Signals:

The "Cockpit":

Think I've got enough crap on my handlebars?

Headlight.  The thing on the shroud is the remote GPS antenna:

Speaking of GPSs, here's close-up of my homemade GPS mount and my bicycle computer/speedometer: