Issue link: http://trailridermagazine.uberflip.com/i/792642
I'm now at a point where the engine is ready to assemble. I've reworked each and every com- ponent (cases, jug, head, crank, piston, main sha , lay sha , kicker sha , shi se- lector, clutch, etc.) and laid them out in egg trays, then just walked through the assembly process. e egg trays are great for keeping parts organized to pre- vent mix-ups while you're doing a build. e bottom-end went together great — on the second try. Both Sachs and early KTM engines require quite of bit of shimming in many places and while the shims are depicted in the parts and service manuals, the amount of shim- ming required varies quite a bit from one set of cases to another. e same man- uals also call a series of measurements for the shims that need to be made pri- or to assembly, but to a large degree it's something of a trial and error process. My fi rst time around with this one, I over-shimmed the main sha , resulting in some resistance when turning, so I pulled it apart and got it just right, zero axial play and no resistance. I also had more fun than anticipated with the top end. I started out with an unbranded piston, which had some features I just didn't care for. Primarily, the anti-rotation pins for the rings were both in line with the intake port, which resulted in a noticeable bite on the port on the compression stroke. I circled back with my primary Penton parts supplier, Al Buehner, and he hooked me up with new Wiseco, which fi t perfect. e en- gine is now buttoned up and I will give it a leak down test before it's mated with the frame. For the few minutes it takes to do a leak down test, it's well advised while the motor is still on the bench. You can skip it and then run your ass in circles trying to fi gure out why you are dealing with erratic performance issues that you can't seem to quite nail down. Too many of us skip this step, then start throwing money at the carb, ignition or other things when their bike doesn't run right, only to do a leak down as the last step. Save yourself some aggravation and get it behind you at the bench. As for a leak down test kit, you can purchase one February 2016 33