How to Set a Magneto Using a Buzz Box
- Rotate crankshaft until desired amount of ignition timing is lined with timing pointer.
- Find out where #1 cylinder segment is in the cap and mark on outside of generator case with marker.
- Find out where last cylinder segment in firing order is in cap and mark on outside of generator case.
- Line up all intermediate oil pump drives and gear drive so as to place the rotor approximately ½ the way between #1 cylinder segment and the last segment in the firing order when the ignition is firmly seated on the manifold or block surface.
- At this time you should check the play between the intermediate shaft and the ignition or the block and the thrust face on the gear. Some play or clearance must be present. If not when you tighten your ignition down you might be jacking your oil pump gear thought the bottom plate of your pump.
- Just snug up the bolt/nut on the retaining retainer so you can move the ignition with a slight amount of resistance
- a.On a Mallory, hook up the buzzer to the orange & yellow primary wires and turn it on. The buzzer may be buzzing now or it may not--not to worry at this time.
b. On a Vertex, hook one wire to primary terminal & the other to ground.
- Determine which way the rotor rotates and hold back against it with your thumb, applying a few ounces of pressure.
- Turn the outside case of the ignition against the rotation until the buzzer just stops. You might have to do this 2-3 times to get the feel of it, but the mag will fire just as the buzzer stops (this is when the point opens).
- Tighten up the ignition clamp bolt/nut until the ignition will not turn.
- To check if you're right there in the ball park ignition wise, reach up and grasp the rotor and turn it the way you did before. It should buzz when back pressure is applied to rotor; and quit buzzing with reduction of pressure.
- Be sure to turn off buzzer or the 9v battery will discharge.
How to Leak Down a Barrel Valve
- Adjust Butterflies Air Gap
- Block Off all Injector Lines & Returns except for Hat Nozzles
- Connect Dual Gauge Tester to Outlet of Compressor
- Set Air Compressor to read 100psi on Supply Line Gauge
- Connect Tester to Inlet of Barrel Valve
- Read % Leakage on 2nd Gauge
- Adjust Linkage on Barrel Valve for Desired Leakage
Engine Cylinder Leakdown
- For most accurate results, engine should be up to operating temperature.
- Remove all spark plugs.
- Rotate crankshaft until piston being tested is at top dead center of compression stroke.
- Screw the spark plug adaptor hose into spark plug hole, making sure the o-ring is seated properly.
- Connect leakdown tester to a good source of compressed air, preferably a filtered and water trapped source.
- Adjust the regulator on the leakdown tester so that the supply line can be set to indicate 100 pounds. If you use more or less than 100 pounds, the ratio between the gauges won�t be correct.
- Connect the spark plug adaptor hose to the coupler of the leakdown tester.
- Read the leak down percentage on the opposite gauge.