starter clutch failure
 

I have a 150cc Hammerhead Twister...
This kart is suffering from starter troubles... The design of the starting system in this engine is such that there is no direct gearing engaged during a start sequence, but rather a 'clutch'. this start clutch never grabs... Have any of you experienced this symptom? What can I do about it? Any help is greatly appreciated...

Are there other engines I can install that easily fit, and that don't have this design?

Thanks folks...

D~