Converting a XR 650 to EFI

5 replies to this topic
  • ogre6br

Posted September 15, 2005 - 05:11 AM



Just wondering if anyone has considered or has any experience with EFI bikes??

How difficult would it be to convert a 2003 XR 650 to EFI??

roughly what would be involved to complete the convertion??
What possibly would be gained from the exercise?


  • qadsan

Posted September 15, 2005 - 06:53 AM


Optimum Power has been selling fuel injection kits for the Yamaha YZ250/450's. They sell the parts and other development tools if you're interested in adapting their system to other bikes.


Difficulty is rather sujective in that one persons ceiling is another persons floor. If you've got experience in electrical and systems engineering, then this will be a much easier project than if you have little experience in this area.

There's plenty that can be gained. You'll be able to custom tune the fuel and spark delivery for specific needs. If done correctly with the right sensors tied into your system, you'll experience improved throttle response, improved power, lower emissions, lower fuel consumption, possibly longer engine life, better overall rideability at various temperature / altitudes, etc.

Fuel Injection is coming to our kinds of bikes before this decade is up. More states are testing, implimenting and or readying equipment to smog test motorcycles and emission standards are becoming increasingly difficult with time. One of the ways the manufacturers are going to meet these standards is to impliment some type of engine management and fuel injection system.

Fuel Injecting the XR650R would be a fun project if you've got the time, money and drive to do so. I haven't yet heard of anyone who has done this to a XR650R, so maybe you'll be the first if you decide to pursue it :banghead:

  • bcdirt

Posted September 15, 2005 - 07:43 AM


I found this in the optimum-power GP control frequently asked questions area. Seems like a really interesting idea, although like qadsan said it may be pretty difficult to do unless you have experience with EFI systems. Wouldn't that kind of control be nice though! I'd love to be able to switch engine settings with the push of a button.

From the GP control site:

Q. Will GP Control adapt to a model you don't make a system for?
A. We'd like to just say "no" but given enough engineering support, technical expertise, time and money, it could be possible to adapt one of our model specific systems to some other bike. The OEMs try very hard to keep their operating strategies a secret, so it's no simple task to create calibrations that will improve on stock. There's also packaging and electrical hardware and delivery issues that need to be worked out. We employ some of the finest engineers and technicians in the world to produce products superior to the huge factories, so it's no easy feat.

We do our best to discourage anyone from trying to do this because we know what it really takes, and costs, to create a system that will perform to the highest possible level.

Lots of people call wanting to tackle some really interesting projects. Some are one of a kind, others are looking for a potential business opportunity, some seem easy, others quite bizarre or complex. If someone does elect to proceed, they must do so at their own risk. Our engineering and design resources are fully consumed by the in house GP Control projects. We simply do not have the vast amount of additional resources necessary to accommodate special requests. (Back to menu)


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  • xr_stamm

Posted September 15, 2005 - 07:55 AM


I converted my Ducati to fuel injection and tuned it myself (without a dyno). I would not suggest this for everyone. I work for one of the Big 3 and do this all day long, and it had me cursing at times. Here are my words of advice to those that choose to do this.

1) Build a bulletproof wiring harness. Spend the money on good connectors. Mil-Spec if you can afford it. No bullets, spades, or scotch locks please.
2) Buy a good lambda meter and sell it when your done tuning. Good = greater than $300. NTK, Horiba, Bosch. Don't just use any O2 sensor.
3) Buy a controller that has data logging capability. Why spend $80/hr for a dyno session when you can putz up and down your street for free? Sure it takes time, but you can make it quick.

Keep in mind that you will be riding with a laptop at your side for the first 1000 miles until you convince yourself that all is well and the new injected beast can be trusted. Leave the umbrella at home, it rains. Leave the laptop at home, the bike screws up. It is a rule. Trust me.


  • qadsan

Posted September 15, 2005 - 08:46 AM


Good points about the wiring harness and especially the connectors. That's one area that will cause a lot of problems, especially intermittent issues over a period of time if the wrong connectors are used. Good points :banghead:

Did you also incorporate a knock sensor and tie it into a spark advance / retard table?

Sounds like a fun project, but I'm sure it would have plenty of hair raising & head banging moments :lol: :applause:

  • xr_stamm

Posted September 15, 2005 - 12:42 PM


I could put in a knock sensor, but I have opted not to. My biggest complaint on the Duck is the idle. It could really use an IAC motor to trim the air. Overall there are some inexpensive ECU systems on the market to try. I'll offer my two cents if anyone is brave enough....

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