Carburetor mounting angle?

Discussion in 'General Questions' started by SuedePflow, Jun 11, 2013.

  1. SuedePflow

    SuedePflow Member

    Hey all. I'm new to the forum and in the process of building my first motored bicycle.

    I'm using one of the common 50cc kits, but I'm putting it on a BMX bike. Due to the size and shape of the frame, I'm mounting the motor under the seat, above the rear tire as apposed to in the middle of the bike. The easiest/bet way to fit the motor there, the intake side leans back instead of forward like normal.

    My question is in regard to the angle in which the carburetor sits. Is this angle critical? Will I have problems with the intake side of the motor leaned back? Any info on the subject is appreciated.

  2. Purple Haze

    Purple Haze Active Member

    The carb has to be level, or close to it, for the float to work correctly.
    SuedePflow likes this.
  3. SuedePflow

    SuedePflow Member

    So, I could mount the motor at any angle that I want and then modify the intake manifold so that the carb sits level? Is that feasible?
  4. Purple Haze

    Purple Haze Active Member

    Yes, that is the biggest advantage of a 2-stroker. Think chainsaws and weedwackers. They use a diaphram carb with no float, but as long as the floatbowl is close to level, the angle of the engine is irrelavent. Of course, if you go to extremes on the angle, exhaust and chain routing come into play.
  5. jaguar

    jaguar Well-Known Member

    I am not sure if it was Mikuni or Dellorto, but one of them lists 30 degrees as the maximum angle from horizontal that is allowable. That may be something universal amongst carburetors.
  6. SuedePflow

    SuedePflow Member

    I reworked the intake manifold yesterday and the carb now sits level. Thanks for the info, guys.


    zippinaround likes this.