Problem:
I just built this bike and I think I'm actually getting it to start, but the torque its outputting is not even enough to keep it running or overpower the internal friction.
3 principles of combustion:
1. spark
☑ Installed aftermarket 3 prong spark plug (tweaked the gap a little with pliers)
☑ Installed new CDI (one that arrived in kit was dead. The spark plug boot plastic fitting was also broken.)
☑ ~6V output at external magneto wires
☑ Consistent sparking when walking bike at speed
☑ Measured a voltage output at spark plug boot (don't remember what it was though)
2. compression
☑ Noticeably harder to walk or pedal when spark plug is installed.
? Engine head unscrewed and reinstalled because spark plug didn't fit in frame the way it was originally angled. Is it possible that, now that I've flipped the head around, the combustion isn't happening dead center on the spark plug?
? The piston head is pointed upward in the center. Is this expected? (#2 and arrow heading toward exhaust)
3. fuel
☑ Carburetor intake manifold fitting is snug (but I don't think it came with a gasket. Do I need one?)
- I used a premium fuel blend (switch to regular?)
- Its pretty cold outside.
- Located at altitude but using stock carb (not much difference when engine is running between choke on and choke off)
- Doesn't seem to start well at all without pushing in (fuel flood knob? you know, that button on the carb) a few times. (Is this expected or not?)
Is there anything I missed? What should I do first, which of these seems most important?
I just built this bike and I think I'm actually getting it to start, but the torque its outputting is not even enough to keep it running or overpower the internal friction.
3 principles of combustion:
1. spark
☑ Installed aftermarket 3 prong spark plug (tweaked the gap a little with pliers)
☑ Installed new CDI (one that arrived in kit was dead. The spark plug boot plastic fitting was also broken.)
☑ ~6V output at external magneto wires
☑ Consistent sparking when walking bike at speed
☑ Measured a voltage output at spark plug boot (don't remember what it was though)
2. compression
☑ Noticeably harder to walk or pedal when spark plug is installed.
? Engine head unscrewed and reinstalled because spark plug didn't fit in frame the way it was originally angled. Is it possible that, now that I've flipped the head around, the combustion isn't happening dead center on the spark plug?
? The piston head is pointed upward in the center. Is this expected? (#2 and arrow heading toward exhaust)
3. fuel
☑ Carburetor intake manifold fitting is snug (but I don't think it came with a gasket. Do I need one?)
- I used a premium fuel blend (switch to regular?)
- Its pretty cold outside.
- Located at altitude but using stock carb (not much difference when engine is running between choke on and choke off)
- Doesn't seem to start well at all without pushing in (fuel flood knob? you know, that button on the carb) a few times. (Is this expected or not?)
Is there anything I missed? What should I do first, which of these seems most important?
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