problem with bevel gear

[hcrft]

i fired up my bike today. but the bevel gear wont stay attached to the crankshaft. it turns out that this is what i originally thought was a problem with the clutch engaging. do you have any experience with the crankshaft components? the semicircular bond wont stay in place, so the bevel gear spins freely around the crankshaft transmitting no power. looking at the set up, i just dont see how these parts would wear easily, and anyway the engine is fairly new. i dont know if i need some kind of adheasive or what. i plan on ordering the gear, column bolt, semi circular bond, and round spring gasket. but what if its the end of the crankshaft that these parts attach to ? any help woul be grat. thank you

 

[Ludwig II]

Is there a taper involved? It might be as simple as removing the gear, making sure all surfaces are clean and dry, and reassemble with a lot of care and force.

 

[Kioshk]

Woodruff key slipping? There are a few threads addressing this specific problem; do a search.

 

[chainmaker]

This was the very first problem I had with a mb. Turned out the wooddruff key came out and fell behind the gear.

 

[biknut]

It sounds like you're over looking something. It would be impossible for the pinion gear to turn on the shaft with the key in place.

Make sure that when you install the gear it's not pushing the key out of place (a common problem).