My Honda CBR 600 RR Motorized Bike Build

Discussion in '4-Stroke Engines' started by CVIN13, Aug 17, 2014.

  1. CVIN13

    CVIN13 New Member

    I started out with a 24" mountain bike that I had lying around. The rear derailer was broken so I decided to get rid of the entire original drive system. I bought an 80CC kit from gokartsusa.com and a week later I had my engine. In addition, I bought a pull start from ebay. Then the build began.
    View attachment 53868 IMG_1727.jpg
     
    Last edited: Aug 17, 2014

  2. CVIN13

    CVIN13 New Member

    Continued

    From the beginning I realized that this build was not going to be easy. It all started with getting the pedals off which was a struggle. I had to buy a puller and they eventually came off. Next I painted the whole bike frame black. Aside from putting the sprocket on the wheel everything was a struggle. All of the parts from the kit seemed to be one centimeter too big for the bike. I had known it was going to be close but I was going for a sport bike kind of look. The motor was nearly impossible to fit into the frame. But, in the end with a lot of persuasion, improvising, cursing and blood sweat and tears I finally got the motor into the frame. I needed to use a 90 degree pipe bend to hook up the carburetor since there was no room in the frame as you can tell from the picture. I bent the exhaust pipe in order to line up the motor correctly. Then I added the clutch assembly to the bike.
    View attachment 53869
     

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  3. CVIN13

    CVIN13 New Member

    Continued

    Next came the issue of the chain. The dang thing would not cooperate. It was either hitting the frame above it or below it. In the end I messed up the chain from the kit and ended up replacing it with a size 41 chain from tractor supply. I finally sized it right and after a long struggle with my push tool I finally had the tensioner and the chain in the right place. Next I took apart the carburetor placed the throttle cable inside, and reassembled the whole thing. Next I put the twist grip throttle on the handle bars along with the clutch control. I pulled off the engine cover and installed the pull start from ebay. Lastly I added the gas tank and fuel lines and was more than ready to give her a spin.
    View attachment 53870 IMG_1755.jpg
     
  4. CVIN13

    CVIN13 New Member

    Continued

    That didn't happen. The dang thing would not start. Now that being said I couldn't just ride around like a normal motorized bike would because I removed the pedals and original bike chain (not that they worked anyway). So I needed to pop start the bike or ,as I had hoped when I bought the pull start, just start it like a lawn mower. Neither worked. Once or twice I got a good pop but never got it running. The pull starter failed and was grinding against itself so I ended up removing it. I was frustrated and it was time to go back the drawing board. What is the trifecta that I needed to get the motor running?
    Fuel, air and a spark.
    Fuel
    Well the fuel line was connected. I was told by a friend that the fuel filter wasn't worth putting on so I removed that. but as far as I could tell the fuel situation was in good order.
    Air
    I took apart the carburetor the air filter was clean and the choke mechanism was working properly.
    Spark
    This is where it got interesting. The wire to the spark plug could be unscrewed from the spark plug cap and I realized the wire was not reaching the screw that linked the wire from the electric box I stripped the wire and put it all back together. Now I knew for sure that the wire was connected.
    I attempted to start it again and got some promising noises from the engine but still no riding for me.
    Then something weird happened. I heard the engine giving off a deeper louder and angrier sound when I tried to start it. With this as my new inspiration I tried hill starting it again and this time the engine roared to life. When I returned from my victory lap glowing with triumph I discovered why the engine had suddenly become louder. The end of the exhaust pipe had come off. It was the cap with the small hole in it circled in red in the picture below.

    View attachment 53871 redline.jpg
    However, the next time I tried to start the bike it would not start and finally I discovered why. The valve that attached the fuel line to the carburetor was a piece of junk. When I disasembled it the small rubber stopper inside was shredded and the little pieces that had torn off had blocked the holes which allowed fuel to flow into the carburetor. I cleaned it out and instead of replacing the valve I just screwed a piece of rubber over the area where it had been. Then it sprang to life again.
    In the process of all of this I had broken 2 spokes on the rear wheel and therefore the wheel had become bent. I replaced the rear wheel with a 26" wheel I took off an old bike. In order to do this I needed to remove the rear break assembly.
    Now it was time for the fun part, adding body panels and a subframe to mount them on.
    I basically started with a board along the bottom and added a foot rest made from a pipe 3/4 inch in diameter and 1 foot long. Next I made the rest of the subframe using scrap wood around the house. Finally I cut the rest of the body panels and attached them to the subframe. I made the head out of wood and did the curved parts with bondo.
    View attachment 53873
    WP_20140816_004.jpg


    Lastly, I painted the whole thing black and this was the end product my own Honda CBR 600RR.
    View attachment 53872
    WP_20140817_001.jpg
    In the end this is more a motorcycle than a motorized bike but hey I think its really cool and I hope you do too!
     
    Last edited: Aug 17, 2014
  5. Ollie

    Ollie Member

    Cool idea, have you managed to find way to start it other than a hill start?
     
  6. CVIN13

    CVIN13 New Member

    Not yet it seems to work well enough as is. I would love to try and figure out a way to make an electric start using an old drill and the pieces of the faulty pull start.
     
  7. Ollie

    Ollie Member

    Yeah, that would be handy. I bet some fat street tyres would look good too. What are your future plans for it?
     
  8. CVIN13

    CVIN13 New Member

    I agree but I don't know if the tires would fit in the frame! And as far as future plans go I'm not so sure. I leave for college soon and I can't take it with me so it looks like its going to be sitting in the shed until next summer. I would love to add headlights and a speedometer as well as a rear break light and mirrors but for now the moneys dried up as has my time. Next summer will be the time for all of that!
     
  9. Ollie

    Ollie Member

  10. CVIN13

    CVIN13 New Member

  11. Ollie

    Ollie Member

    Haha, awesome! :)
     
  12. CVIN13

    CVIN13 New Member

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