MAGNETO IGNITION

MAGNETO
The flywheel magneto used on this model of engine is made up of three component parts; flywheel, stator plate with coil, and breaker assembly. The breaker box mounted on the right hand side of the crankcase contains the points, condenser and ground switch.

BATTERY IGNITION

IGNITION COIL - 12 Volt
Engines furnished with battery ignition, instead of the standard magneto ignition system, use a conventional 12 volt ignition coil. The same breaker point assembly is used for both types of ignition, but the flywheel and fan end bearing plate differ. The following "Breaker Point Adjustment" and "Timing" procedures apply for both magneto and battery ignition systems.

1. With engine running at operating speed, pinch neoprene breather line so that it is completely shut off

2. Hold tubing closed, for a period of not more than 20 seconds, and then release. 3. If oil leak continues, repeat procedure after a 5 minute interval. If this does not remedy the condition; stop engine, take off inspection coverbreather assembly and wash in solvent.

IGNITION SPARK
If difficulty is experienced in starting the engine or if engine misses firing, the strength of the ignition spark should be checked. Remove spark plug from cylinder head and connect ignition wire to it. Turn engine over several times by means of the rope starter sheave, as illustrated in Fig. 9, and observe the spark at the plug gap. If a good strong spark occurs, the ignition system can be eliminated as the source of trouble. If there is a weak spark or no spark at all, follow instructions in "Breaker Point Adjustment" paragraphs. Also check ignition wires, spark plug, condenser and coil.

BREAKER POINTS

REPLACEMENT and ADJUSTMENT
The magneto breaker points, Fig. 10, are contained in The breaker box on the right hand side of the engine. A push pin, actuated by a striker plate mounted to the camshaft, operates the breaker points at half engine speed. When ever points are replaced, inspect push pin for possible wear and replace if necessary.

If oil leaks from breaker box, refer to "Crankcase Breather" for cleaning of breather valve seat. At least twice each season or when ignition spark becomes weak, remove breaker box cover, inspect the points and check the gap opening. If there is evidence of pitting or pyramiding and it becomes necessary to resurface or replace points, it will also be necessary to readjust the gap and retime the engine. f

STATIC TIMING PROCEDURE: See Fig. 12.
1. Disconnect coil primary wire at bottom of breaker box. Remove breaker box cover.

2. Timing mark on flywheel can be observed thru the hole in back plate of flywheel shroud, just to the left of the breaker box. Since breaker arm operates at half engine speed; line up flywheel timing mark and pointer, with engine on compression stroke. The compression stroke can be determined by turning starter sheave in a clockwise direction and watch for breaker arm movement by push pin in breaker box.

3. Connect one lead wire of the timing light DF-81-S1 to ground and the other to the terminal stud at bottom of breaker box. (With points closed, the timing light will be on)

Replacement of points: Turn crankshaft over so that breaker push pin is at its inner most position (low point of camshaft striker plate). Mount breaker assembly to crankcase by means of brass fulcrum pin, and tighten pin to 22 inch pounds torque (do not overtighten). Be sure breaker arm spring is squarely mounted (if spring is cocked, points will be out of line). Mount lockscrew with washer and proceed with point adjustment and timing.

The normal breaker point gap is 0.023 inch at full separation. However, the fixed running spark advance of 18° is regulated by the point opening, and thus a slight deviation from 0.023 may occur when obtaining an accurate spark advance with a timing light.

With reference to Fig's. 10 and 11, adjust breaker point gap as follows, and then proceed as per instructions in Timing paragraphs.

1. Turn engine over by means of the starter sheave until breaker arm push pin is at the high point of the striker plate (maximum point opening).

2. Loosen contact support plate lockscrew very slightly Oust enough so that plate can be moved).

3. Place a 0.023 inch feeler gauge between the points.

4. Insert screw driver in adjusting slot and open or close points as required, until a slight drag is felt while sliding feeler gauge between points.

5. Securely tighten lockscrew and recheck point gap.

TIMING MAGNETO or BATTERY IGNITION The fixed running spark advance of 78' is regulated by the breaker point opening and reasonably accurate timing is obtained by simply setting the breaker point gap to 0.023 inch, as explained in "Breaker Point Adjustment". However, static timing with a continuity light, as illustrated in Fig. 12, is more accurate and advisable. The timing light is Wisconsin Motor part number DF-81-S1

A pointer is located in the crankcase, just to the left of the breaker box, to visibly check the advance timing mark on the rim face of the flywheel.

4. Slightly loosen lockscrew on contact support plate (just enough so that plate can be moved).

5. Insert a screw driver into support plate adjusting slot and close points so that light is on, then turn screw driver slowly in the opposite direction until the light just goes out. Retain points in this position and securely tighten lockscrew.

6. As a final check; turn flywheel counter-clockwise until timing light is on. Then, slowly rotate flywheel clockwise, and stop immediately when light goes out. At this point, mark on flywheel should be in line with timing pointer in crankcase.

7. Assemble coil primary wire to terminal stud and mount breaker box cover.

MAGNETO SERVICE INSTRUCTIONS

If engine will not start or if it is hard to start and does not run properly, make the following tests to see if the magneto is at fault:

1. Check carefully for loose, corroded, broken or worn ignition wires.

2. Check the spark; refer to "Ignition Spark" and "Spark Plug" paragraphs.

3. Check points for cleaning, alignment and adjustment. If badly worn or corroded, points and condenser should be replaced. Refer to "Breaker Points".

4. Magneto coil replacement should be done by a competent mechanic using adequate test equipment. The coil can be tested in the following manner and without removing the flywheel: Position flywheel so keyway is at the bottom. Remove the coil primary lead from the terminal connection at the breaker box and the spark Plug lead from the plug. The coil can now be tested using the primary lead, the high tension lead, and the engine block as the ground connection.