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. 

Thursday, November 1, 2012

Honda Hobbit PA50 Rear variator and misc

Hello long time blog readers.  Long time, no read.  Here are some pictures that never amounted to a reason to post.  I sold a Hobbit LTD to my friend Max, and then he discovered a clever way to disassemble the rear variator using a planting crate.  It wedges the cheeks open nicely.  You can see the cam on the left was badly worn and in need of replacement.

What is a hobbit LTD?  It's a PA50II in black with hologram HONDA decals.  They are awesome.

Greg smashed his Austro Diamler forks on adventure ride, so we straightened them out.  Some miss information is passed around that these are hydraulic, but they are actually just very good spring loaded forks.  Nothing a little time in the press wont fix.  Very sturdy.

Don't get your blog hopes up, but I might update this thing a bit more frequently, like say... monthly.  See you in December.

Sunday, March 11, 2012

I just needed to write this down

I'm going to make an intake with tapped holes for mounting and use set screws to put in place for that extra flush look. I was thinking about this as I have been using Tomos A3 headers to make intakes recently and they are such large OD that they require a good bit of filling to let a regular socket head cap screw pass. It was an intake for my loyal pp derbi, which is receiving a new metra kit jug. Upon removal of the stock jug, I realized it had a giant base gasket, leaving nearly two mm of gap between tdc and the head. No wonder that bike never seemed very fast, it was restricted to 20mph when I got it with an intake washer, and also had a bracket on it for an orange flag. I strongly suspect it was originally from Iowa before it made its way over to Nebraska where I picked it up. I might just throw the stock jug back on for the time being to see I'm correct on the speed factor. With 15SHA I and pipe I was only able to squeak 36mph from it.

Sunday, February 5, 2012

Yeti in the New Year

After a nice 3 month break from working on mopeds, I'm back at it. A nice little vacation from fixing bikes left me with exactly one runner. I picked up two more Puchs at auction this January. One was a rigid free spirit, with which I have fallen into vibrat-y love. The full rigid is very enjoyable, and after removing the thick head gasket, upjet the stock 14mm bing and a proma pipe, it goes a screaming 33mph with killer low end, thanks to the 14x45 gearing. I've got a nice Demm Smiley tank to put on it as soon as the petcock arrives. This bike will be my rally backup, and guest rally loaner.

I spent some time working on Rickety Cricket, my freespirit with negrini tank. Got the hydraulic forks installed and the disc brake is ready to stop me. I'll finish the tank mounts soon, and begin to recover the seat. This bike should be blasting with a Kstar70cc kit and simo pipe.

The Derbi was coaxed back to life after the primary coil took a dump at bomb bourbon run. The pietcard cdi was pretty easy to install, although the timing didn't match up with the woodruff key, so I'm running sans key with the stator rotated about 45 deg clockwise. I had to hook up my timing light to get it at 1.8mm btdc. I might scoot it up a bit to 1.6mm, but for now it is working great.

The weather has been so warm that we have been riding bunches this January and February.
See you guys all in Nashville in a few more weeks!