125 sachs porting

[brian kirby]

quote:Originally posted by Mike Lenz

 If you dont know I put a Sachs cylinder on a 73 Jackpiner to try and make a good shifting reliable vintaqe Penton 100

I am familiar with what John D had to do to put the 175 top end on the Sachs bottom end, but how much was involved in putting the Sachs top end on the KTM bottom end? Is it as simple as bolting it up? This might be a good setup for the MT 100cc Works Revenge races, especially since they allow 7" of rear travel, put it in a 74.5 frame and lay down the shocks.

Brian

[Ernie Phillips]

quote:This might be a good setup for the MT 100cc Works Revenge races

Too heavy.

Stick with the SoCal berkie.  You'll race 4 laps on a smooth vintage track.  Who needs 7" rear travel.  And, loose 10 pounds yourself[8D]

Ernie P.
Chattanooga, TN

[brian kirby]

You are right it would be heavy. I do have that other '72 Berkie parts bike/project frame that I could pretty easily set up a laydown rear shock setup using those max travel shocks Works Performance built for the XL250.

Brian

[firstturn]

Brian,
  I do have a 1974/5 laydown shock frame that needs work that I am not going to use.  Let me know if you are interested.

Ron Carbaugh

[brian kirby]

Ron,

I might be interested, does it use a special airbox?

Brian

[Mike Lenz]

Brian,  You have to weld/machine some more metal onto the rear of the cylinder for a base gasket match, make an exhaust manifold spacer and re angle the header pipe end of the pipe if using a Sachs pipe, not required for a KTM 125 pipe. I also reworked the intake setup to not only open up the intake for a 32mm Bing, but to also clear the cases. This is required even with the 28mm bing I used on the 100. I also used the clutch/primary gear from a KTM 125 which is geared lower and lightened, along with the all alum clutch plates and disks. That removes ALOT of engine weight and spinning mass weight. Other than the tranny being a little heavier you wind up with an engine that is similer in weight to the Sachs I would think. you also want to gear it way down or better yet make it a five speed to miss the huge gap from first to second and the neutral between second and third. Did some other things like milling the head, stuffing the crank and porting (well Ron C did that). You wind up with a good shifting reliable engine with a clutch you can abuse without it going away.

Ron, Well as I stated we won it three years in a row and apperiantly scared the others away with your cylinder, even with my petite frame gracing its chassis! Actually, I let one of my boys run the first motos and I ran the second. Since I am not going to use it in the forseeable future you can have it back if you want it.  I did make the base gasket and intake changes needed for the KTM engine, but I think it would still fit on a Sachs lower end also. Maybe a swap for the 125 cylinder if you find a spare???

[firstturn]

Mike,
  I do not need the 100 cylinder, but if I find an extra Pro 125 Cylinder I will shoot you an email

Brian,
  This is a bike I bought years back and it needs some frame work (from rust), but is basically compete with a stuck Sachs 125D engine.  I will send you a email with more details.  It would make a good project as it has the correct swingarm etc.

Ron Carbaugh

[brian kirby]

OK Ron, if you dont already have it my email is bkirby84c at yahoo.com

Brian

[gooddirt]

[8D]