TIMING
              Now for the fun part. If you are installing a C.H. Ignition system  with the CTC and are satisfied with the way your engine currently runs at
  full throttle, you will just need to lock your timing plate at the full  throttle position.

   The easiest way to lock the timing plate is to drill (#36 drill) into the side of the  plate and tap for a 6/32  set screw. It is better to pull off the prop hub and timing
  plate to do this, but you don't have to. Just drill straight in until the drill bit touches  the aluminum timing plate bushing. Now run in a bottoming tap in until  it stops.
  Be careful and do not strip the threads. Now you tighten the set screw and material  at the  bottom of the hole will lock the timing plate.

   If you would want to go back to the throttle coupled system you will have to remove  the timing plate and  clean things up as the timing plate will probably bind up even
  when you loosen the screw. You can use a  bolt in place of a set screw. If you do not  have a tap you can drill a hole and use a sheet metal screw. Just  screw it in and
  lock the plate.

              If your engine is set-up with a TCSA mechanical system or you need to set the  timing for your CTC  equipped engine just follow these steps to set timing.

              To install the CTC module, just unplug the pulse switch and plug the CTC   between the pulse switch and  the ign box. The Deans plugs are correct for a C.H.
  Ignition. That is all there is to installing  the CTC module.

   If you have a C.H. Electronics ignition module with the CTC built-in, just plug it in the same way you would  an ignition for a TCSA equipped engine.

   The CTC module or the complete ignition module can be wrapped in foam and tied   down.
              For an engine using TCSA. set the timing to 28-32 deg Before Top Dead  Center (BTDC) at full throttle  and 2-8 deg BTDC at idle. This is approximately 26
  degrees of total movement. To adjust the amount of  movement, move the push rod  in or out on the bell crank. To adjust the timing, change the length of the  pushrod.

              For an engine using a CTC equipped ignition set the timing by at 28-32  degrees BTDC.
              Most of the Sachs engine builders have settled on 30 degrees BTDC.
              Ask us about other engine recommendations. The setting depends somewhat  on fuel altitude and outside  temp.

              The only way to set timing accurately is with a degree wheel.
                                      
              A degree wheel print-out link is at the end of this page.
              Buy a 6 inch protractor and a paper clamp at your local discount store. Drill   the protractor for your prop  
              shaft then cut out and glue the degree wheel to the   protractor.
              You can also use a piece of lite-ply or what  ever you have around the  shop.
              Attach a pointer to the clamp. Now you have a timing kit.

              Here is another way I have found TDC for many years. Leave the spark plug in  and bring the engine up  on compression, let the compression bleed off, on some
  engines you may have to loosen the spark plug  a little. You will notice you have  about thirty degrees of free travel as the engine toggles back and fourth  past TDC
  right in the center of this free travel is T.D.C. With the timing pointer clamped onto to a cyl  head, set the degree wheel so that the free travel at TDC is equal on both
  sides of zero on the timing  plate.

   We have found the average engine to have about 20  to 30 degrees of free travel, if  there is more than  this check your engine. Do this several time to make sure your
  pointer is on the zero mark when the  engine is exactly on TDC.

   Keep in mind the pointer and zero degrees do not have to be set at the top of the  engine, this is only a  reference.

              Making sure you do not disturbed you timing pointer, put a spark plug in the  plug cap, ground the plug,  hook up the ignition and turn it on. Turn the engine over
  and make sure you  have a spark at the plug.  Turn the engine slowly and see when  the ignition is firing. Set the correct timing by moving the timing plate.

              DO NOT RUN THE ENGINE WITH THE DEGREE WHEEL INSTALLED.

              Now set up and start your engine. Observe all Warnings and Safety  Precautions and use a helper to  restrain your airplane.

              We should always wear a heavy glove when starting model engines, as we do  not heal up a fast as we  used to. Keep in mind any engine with the right (or wrong
  conditions) can hurt you.

   Let your engine warm up and bring it up to full throttle and hold this setting for at  least thirty seconds. You  may have to set your carb a little richer on the low needle
  to get the correct throttle response. Now tach  your engine at fun throttle. Record  this figure.    If your R.P.M. is O.K Leave as is and go fly.

        When you have your engine set where you want it check the timing with a degree  wheel and record this  for future reference.