Mick

[rob w]

Back to the drawing board for the "fork stop bumbers". Contrary to what I was told in the information about this material, the 90-95 durometer urethane is too soft and will not machine as well as I would like. That $50 did'nt taste very well. Well, at least now we know, the next step harder will take us out of urethanes and into plastics.
Mission not aborted but delayed.

 

[john durrill]

Rob,
 think nylon might work? we have some plastic that is used on the boom's on the line trucks. It looks like it would work .
 its white but looks to be a nylon material.
It gives some but holds its shape. if I can find a piece big enough ill chuck it in the lathe and see how it machines. if it looks like it will work ill send you a piece . you may be able to find some stock in black of the same material
John D.

 

[rob w]

John, You're right about nylon, it would work fine here, except it is normally white.
I have two things in mind, UHMW and Delrin, I thing Delrin is the one that comes in black.

Side note: John, what size Lectron would you recomend for a 175, and have you ever tried a Lectron carb on a Sachs 125?

Thanks
Bob



 

[john durrill]

Rob,
 on the 175 I would use a 32 if your using it for trails and enduros and a 34 or 36 for mx.
 the smallest they make a lectron in  is 30 mm. I have one on my 175 conversion . it is huge in size ( Physical size) you would have some problems clearing the pipe on a 125. we had to put a small dent in my pipe and cock the carb about 5 degrees. then use a mikuni cable fitting that lets us angle the throttle cable to the side to make it work.
 if you have a D cylinder on the 125 you might be able to do a Lectron easier than on a B cylinder.
 take a look at the pictures of the intake manifold we made and of a close up of the engine installed to see what I mean. if you do the Lectron on the 175 then you would have one to play with to see what would have to be moved or adapted on a 125 for it to work.
 The 30 mm is a bit small on the 175 but would work well on a 125. it detuned mine and that's what we were looking for. we got a 32 mm for Peters 175 piner and its working well. if you don't change from the stock pipe I can give you a close set up for the needle on the 32 mm. A 34 would need a bit richer needle as it has less vacuum drawing on the needle orifice. I think Al is running a 3/4 on his 175 with a 34 mm Lectron.
 we will give you any info we picked up on tuneing the Lectron doing our bikes , just drop us a line.
John & Peter

 

[Mick Milakovic]

Rob and John,
Thanks for all the leg work.  I'm sure eveyone can tell this project is in good hands.  Good luck and keep us posted!

Mick Milakovic
Delphi, IN
765-268-2570

[nonwing]

Try Delrin.  It comes in two flavors.  One is white the other is black.  The black has graphite or a similar substance in it.  It machines well and will handle a lot of pressure.  I've used the black type it for swingarm bushings.  The machinist who referred me to this stuff says alot of machine tools use this instead of brass or other metallic bushings.

 

[Kip Kern]

If you need the fork bumpers, or any other small plastic/rubber piece, I have had a lot of luck with getting in touch with  plastics/rubber companies and having them make molds and pumping out bunches of them.  I have had a lot of luck finding places to do this for many other Penton/KTM parts, i.e. gaskets parts, etc,  All it needs is someone willing to take the time and "run with the ball."

 

[BrianTaylor]

You can buy nylon in Black we sell it all the time

Brian Taylor

[cardojr]

rob, i've got a chunk of mystery material about 1/2 thick x 10" square (i'm assuming nylon or derlin)-it's white. we use it for material slides for lumber-- it cuts nice-don't know how it machines-it's yours if you want it-let me know-thanks ron card (the other rob meat)

 

[nonwing]

Hi Rob:

My username has nothing to do with hockey LOL.  Among my other addictions I'm a nonwing spint car fan.  Can't stand those barn doors on the roofs!

 

[nonwing]

I need to learn to spell as well... Spint car fan should be sprint car fan.

 

[john durrill]

Rob,
here you go, right from JP himself
http://autos.groups.yahoo.com/group/PentonRestorationandTechGroup/files/Carburetion/amal%20125%20carb%20specs.jpg
John D.

 

[scooterdude]

Hey Guys,
Anyone have a 1980 KTM 250/400 they want to sell? The KTM dealer who bought my Jackpiner for the showroom put me on the hunt. Condition is not important( needs a project )
Thanks,
Jeff