Or almost any other CV carburetor equipped motorcycle!!!


By using batch injection principles you can turn your V-MAX into an up to date
fuel injected superbike, and all for under $1,515.00
And keep your V-boost!!!!!

Check out the kit install and Microsquirt/Megasquirt setup

Here's a few answers to fuel injection that I discovered.

     A lot of people have been asking if they need a trigger wheel for the Vmax. The answer is yes and no.
If you run a batch injection setup like I am on the Roadstercycles the answer is no. All you have to do 
is use the negative side of the #1 coil to control the Megasquirt ECU injection timing. Simple, easy, and
 works excellently. Batch injection means that you just inject continuously like almost all throttle bodied cars built by GM and other car manufacturers. You just adjust your fuel injection as needed. Sequential fuel injection means that you have crank triggers and or cam triggers so you inject fuel exactly at the right moment when the intake valve starts to open. More sensors, more work, more money. The guys at  Megasquirt actually set up a car both ways and realized the extra time and money was not worth the added performance gain which was negligible. I thought about going both ways and decided to keep it simple. I am jazzed at the performance and setup. I hit the starter button and I'm gone. I hope this helps. Also, all fuel injected vehicles have some sort of safety device for shutting off the high pressure fuel pump in case of an accident or lay down. This is something that needs to be added to your EFI project for your own safety and the safety of others. Don't just consider it,
do it.

     Below is a throttle body conversion set up that I developed for the '34 Roadstercycle and
any Vmax motorcycle using stock CV carburetors. If you would like to see the Throttle body
kit in action go to Youtube and check out my videos. Yes, we have applied for a Patent for the 
conversion of  motorcycle CV carburetors into fuel injection throttle bodies.


A Vmax throttle body conversion kit is $199.00 on sale!!!
I do all the machining myself, in my shop in the U.S.A.
The kit does not include injectors, electrical components,
fuel pump, regulator, ECU, etc. It only includes what is in the 
throttle body kit picture which will convert your stock
Vmax CV carbs into throttle bodies. Installation Instructions here.

   With a Megasquirt system like I used you can have a Full Fuel Management System!!! Race, Street, Turbo, Blown, Nitrous, Rev limiter, water injection, and even spark! I would start with just fuel injection first to get familiar with all the settings and how everything works. Make sure you read everything and get familiar before starting your project. The pictures below shows my fuel injection installation on the '34 Roadstercycle. On a stock Vmax engine with a stock air box you would position the fuel block and lines differently to accommodate your particular look and needs. Since I travel to different shows I kept the fuel pressure regulator, fuel pump and ECU visible to be able to show people what parts and pieces are needed to run an EFI system. You can hide a small pressure regulator somewhere and a fuel pump with a regulator built in can be put in your fuel tank. This takes some work but it can be done. That would be the cleanest setup. You will still have to hide the Electronic control unit which are different sizes ranging from the size of a  pack of cigarettes (Microsquirt) to about the size of a VCR tape. This install has the VCR size unit. (Megasquirt I ). 





The above 2 pictures are of the new Microsquirt ECU. This is the newest way to go. Small, compact design
that comes with a 3 ft. wiring harness and a serial port connection for programming through your computer. Size matters and smaller is better for motorcycles. This unit is $400. 

     This is a 2004 Honda 600RR in tank fuel pump. It has a built in regulator with the correct pressure and flow for tuned port type injectors. It even has a fuel level sending unit built in. (the wire with the black square) You could also use this if you purchase the correct fuel gauge. Homework time again. This fuel pump assembly mounts in from the bottom of the tank. There are others that will mount in from the top. This was an Ebay item that I bought for around $40.00 just to take a look at it. It was like new. This is definitely a good way to go!    

 Cost of a typical fuel injection installed on a bike:

  • EFI control units  $200.00 (you build it from a kit)  to approx $750.00.  Mine was a $300.00 kit.
  • External 90 psi. fuel pump around $125.00  you can buy used motorcycle internal pumps (Ebay) and install them in your tank and they usually have fuel pressure regulators built in. Remember port injectors take about 45 to 53 psi. Again do your homework for the correct pump.  
  • External fuel pressure regulator $30.00 to $100.00 You need one that regulates down to 45 to 53 psi.
  • Fuel injector hose, rubber about $3.00 a ft.  If you want the pro look with stainless hoses it's going to cost a lot more,
    so do your homework. I just paid $18.00 each for "4"  1/8"npt to -4 stainless hose fittings. 
  • Extra fuse panel. $15.00 to $75.00 Again that's up to your taste. I paid $65.00 for a really nice one. Main fuse, fuel pump fuse, 2 fuses for the 2 injector banks, ECU fuse.
  • Electrical wiring. I'd figure a $50.00 if you do your own wiring. Most of the ECU control unit people have harnesses you can buy. This is a nice clean way to go and quicker than you wiring it. 
  • Injectors about $50.00 apiece, I use 19 lb. Bosch type from a Ford mustang. Remember we are talking about port injectors not throttle body injectors. I use port injectors to turn your CV carbs into Throttle bodies! Motorcraft PN# is E5TE-A3B It will cross over to different part numbers for more flow if you need it.
  •  Air, coolant and oxygen sensors. $100.00
  • Throttle position sensor $60.00
  • Extremely important is a rollover switch or bank angle switch.. In case of an accident this would or should shut off the high pressure fuel pump so fuel would not be pumped uncontrollably if a fuel line
    or injector would be ruptured. This is a necessity not a suggestion.  

So quick middle of the road addition here;  This is just an approximate, DO YOUR HOMEWORK!

Bank or Rollover switch     $100.00   (This is very important in case of an accident, it shuts off the fuel pump)
EFI control unit                  $400.00   (remember you can pay more or less if you can solder and use a meter)
Fuel pump                          $125.00
Fuel regulator                     $50.00
Hoses and fittings               $100.00
(not stainless)
Fuse panel                          $50.00
Wiring harness                    $50.00   (it will be more if you buy one from the ECU sellers)
Injectors  need 4                 $200.00  Motorcraft PN# is E5TE-A3B (I've found them rebuilt for $22.95)
Coolant temp sensor           $15.00
Air temp sensor                  $15.00
Oxygen sensor                    $50.00   (unheated) Read about heated and unheated O2 sensors.
Throttle position sensor.      $60.00
My CV to TBI kit               $199.00      Kit instillation instructions here.
Sub total:                         $1515.00*  (With my CV to TBI kit.)

*If you don't use mine you have to add on some type of  throttle body setup. Here's what I discovered:

GSXR throttle bodies from $50.00 to $300.00 on Ebay,  you have to split them apart, make manifolds to mount them since they are not spaced correctly for the Vmax. Build throttle linkage, redo the fuel lines, since you just cut them in half. Unless you have a machine shop or a friend with a machine shop it's going to be quite a  project. I have a full machine shop and I didn't want to do it. The good side is that the GSXR throttle bodies usually come with a throttle position sensor. So the bottom line is this, EFI is rather expensive to add on, I thought about it long and hard before I decided to do it. But now that I have I've realized it's the only way to go to revive the Vmax! 

If you are going to build a pure Dragbike then you should check out Wildbros  around $5000.00 for a full management kit or Extrudabody to put together a set of throttle bodies from pieces. You still have to build manifolds if you buy Extrudabody parts. Both places sell very nice looking units. Again and I can't stress this enough do your homework it will pay off in the end.

I really hope I've helped sort out some of the mystery of add on fuel injection for motorcycles.  If you have any questions or thoughts feel free to ask, I would love to hear from you and answer your question and post
them so others can learn more about EFI.


Copyright by Fleming Engineering 2008-2013