A.R.D. Belt Driven Magneto For Triumph Unit Twins
1) Remove the original timing case. Remove the point breaker cam which drives from the exhaust cam. Remove all wires from the points, tape them or otherwise isolate them and put them aside out of the way of the new installation. These wires are no longer a part of the ignition system.
2) Remove spring clip and oil seal from the case just removed and install them in the A.R.D. timing case cover. (We suggest you replace the seal with a new one). Check installation of seal to be sure it is installed exactly as it was in the original timing cover. The upper seal has no spring clip. The Triumph cover and the A.R.D. cover are exactly the same except for the magneto drive.
3) After installing seals in the A.R.D. timing cover, install the new timing cover exactly as you would install the old one. Use the original screws, and a sealer recommended by your Triumph dealer as required.
4) Insert the lower drive shaft with the belt on over both pulleys. DO NOT BEND OR STRETCH BELT. Now insert belt, (use original bolt that held point breaker cam to the end of exhaust cam shaft) into the lower drive pulley and tighten.
5) After tightening bolt in step 4 above, back it off so that the pulley is free to turn on end of exhaust cam shaft.
6) Remove distributor cap from magneto head. Turn the pulleys CLOCKWISE until the points of the magneto are just beginning to open. At this point note the position of the rotor in relation to the pins inside the distributor cap. The pin that lines up with the distributor rotor is the one that will fire now. Trace the high tension wire from that pin and connect to right or left sparkplug and then connect the other wire to the other plug.
7) If you connected the wire that will fire to the left sparkplug, this will be the one you will time and vice versa. Let's assume you will use the left one. Rotate the engine to locate compression stroke on the left engine cylinder and set the piston 7/16" before top dead center ON COMPRESSION STROKE. The position will be 36 degrees before top dead center on the degree wheel. Recheck step 6 to be sure points and rotor did not move while you set the engine.
8) Tighten bolt on lower pulley (step 4) then tighten the two set screws on the lower drive pulley after making sure of the timing by rechecking. Replace the distributor cap on the magneto head. MAKE SURE SCRIBE MARKS ON MAGNETO HOUSING LINE UP WITH SCRIBE MARKS ON THE DISTRIBUTOR CAP to be sure cap is properly centered. Replace belt drive cover and the installation is complete.
9) The screw with two nuts on side of magneto housing is for grounding kill button switch. DO NOT CONNECT ANY HOT WIRE TO THIS TERMINAL. A push on momentary switch to ground (frame) will short ignition and stop engine when connected to this terminal with a length of wire.
Note: If using Hunt type magneto with dual outlet ignition coil and no distributor rotor and cap, use Joe Hunt instructions for magneto in conjunction with these ARD cover installation instructions. (See 334-01 ARD Cover Kit for Triumph Unit Construction Twins.)