Friday, December 7, 2012

Derbi starter clutches

I picked up another yellow Derbi TT this summer.  Found it in a barn out in rural Indiana, and it had been fixed many times by the farmer who owned it.  The seat was screwed on to the seat bracket with self tapping sheet metal screws, and it has a motorcycle tail light.  I finally decided to pay it forward, since it sat in my shed for about 3 months without me touching it.  So I traded it to Travis for a Motron, and we began to fix the problems with the Derbi.  He cleaned the carb, set the points and replaced the fuel line, and it fired up and ran. 

Judging by the horrible scraping sounds and how it would not idle at a stop, but would idle when you would just start it, we inspected the starter clutches.   The face of the clutch where the starter clutches drag was worn away from metal on metal contact, it was depressed about .2mm from where it should have been. 

 The pads were completely gone, a spring was broken, and a large amount of clutch bell was worn away from this bike being endlessly started on the farm by 14 year old boys.

 Since we didn't have any new derbi starting clutches, we just raided a hobbit set, and the only modifications it took to install them was drilling them with a 7/16ths drill bit.

  Here is a shot of the hobbit starting clutches in a derbi starting clutch.  Pretty sure that was the size, anyway.  Now it starts much better and idles fine since the shoes are not dragging the engine constantly.