Hey guys I just wanted to show off my project and start a log. The bike is a 1980 CB650C that I have owned for 8 years and it was my first street bike. I have always fought with carbs on this bike so naturally I want to upgrade to fuel injection. I know that there is a few guys out there with CB750's that have fuel injected them but I believe that I am the first to do a CB650. I already have a start on this project I have most of the components on hand or ordered at this point. I have a Speeduino NO2C on order to control this project, which is a small opensource ecm based off the arduino mega.
Here is the bike partly dissembled but you get the theme of the bike. It is mostly stock with a top end rebuild, mac 4-1 exhaust and the rear frame bobbed.
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I plan to use modified throttle bodies off of a 2001 CBR600 F4i. These throttle bodies have the correct throat spacing for cylinders 1-2 and 3-4 but 2-3 does not line up. The spacing between 2-3 is 5mm to close the stock CBR600 throttle bodies need to be spaced out 5mm, obviously. The correct spacing is 75mm-80mm-75mm. Here is a picture of the stock throttle bodies.
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In order to get these throttle bodies to work on the CB650 a 5mm spacer needs to added in between the throttle bodies. This picture shows a 5mm that I 3d printed for mock up. The final spacer will be turned out of aluminum.
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The fuel rail, the spring connections for butterflies and idle rod need to be widened as well. I have the fuel rail spacer brazed on one side so that once the aluminum spacers are done I will have the correct spacing. I have also got the mount for the spring connection between the throttle bodies in the correct spot.
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Here's some shots of the throttle bodies on the motor. I had to machine some aluminum bushings on lathe that press over the intake spigots on head so the CBR600 boots would fit.
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I plan to use the swirl pot fuel pump from a Honda VT 1300 motorcycle.
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