By aevald
Date 02-12-2007 03:49
Edited 02-12-2007 03:51
Hello again GMANIAC, if you have a voltage tester you should check to see that you have voltage to the battery side of the coil once you have turned on the key, also check to make sure that the negative side of the coil has continuity to ground. If not, you will need to track down why you don't, another thing you can do after doing the first thing that I suggested is to disconnect the positive wire to the coil and jumper that terminal to 12volts +, also disconnect the negative wire to the coil, while holding the high tension wire from the coil next to the engine block, touch the negative wire to the - terminal on the coil, only ground this wire momentarily, this should trigger a spark if the coil is working properly. If that test yields a spark then reconnect all of the wires and try cranking the motor over with the high tension lead from the coil next to the block as done previously, this should also cause sparking while the engine is cranking. If you don't see any spark in this second test I would start looking at the points, condenser, cap, or rotor.
One other item to consider has to do with any low-oil pressure shutdown switches. Sometimes machines that are so equipped will have the 12 volt supply to the coil fed through this pressure switch, if the switch is faulty it won't allow the engine to start due to not allowing voltage as it should. This switch is usually a (normally open) contact switch which allows the oil pressure as it builds up to close the contacts in the switch and allow the engine to start. Thus if the engine should lose oil pressure, it will cut the voltage to the ignition system and shutdown the engine.
When you're at this point you may want to go ahead and do a compression test, generally there is a range that is allowable before you need to worry about any major engine repair. Sometimes, what is more important in this instance, is that all of the pressures are with 15 to 20 PSI. of one another. Also do a dry test and then do a wet test by shooting a little shot of oil into the cylinder before testing the pressure, if you notice an appreciable pressure increase with oil this is a sign of the rings having wear. If you have one or more cylinders with low pressure readings and they don't increase any with the addition of oil, check the valve adjustments and adjust.If they still remain low, it is generally a sign of burnt valves or seats.
It also sounds as if you would be doing yourself a favor by trying to get ahold of a service manual on this engine, it will likely also have a trouble shooting section that could help you out immensely. Keep us posted and good luck. Regards, aevald
Plugs out. Ignition off. Finger over the number 1 plug hole. Have someone crank the engine by hand until you feel pressure on your finger (note the direction the distributor rotor is turning while doing this). Then continue cranking in the same direction until the top center timing mark is aligned. I am sorry I don't know where it is on this engine but the lower pulley is a usual place (somebody help me here). Loosen the clamp on the distributer and turn until the cam follower on the points is on a high spot on the cam. Gap the points, usually .015 inches but a responder above says .025 and he may be quoting a manual that I don't have (watch for a built up peak on one point which should be filed off before gap is set)(a new set of points and a condensor is not expensive, probably available at the local auto parts, and recommended). Now you need a test lamp. First test it across the battery. Now ignition to on, one side of the lamp to ground, both low tension terminals on the coil should light the light. If neither does check for an oil pressure switch and put a jumper across it if you find one. Perhaps the ignition switch is bad. Perhaps the circuit is fused and the fuse is blown. If only one lights the lamp. Check that you haven't inadvertantly closed the points. If not take the wire off either at the coil or at the distributor. If the light now lights you have a ground in the distributor. If not you have a bad coil. When you get it so both are hot with the points open rotate the distributor body till the cam follower is at the flat part of the cam. Test at the terminal on the side of the distributor, the light should be out. If not points are bad. If you now take the center wire from the distributor cap and hold it 1/4 inch from the block and open the points with your finger you should get a nice spark. If not suspect a bad coil. Now testing at the terminal on the distributor, rotate the distributor body opposite to the way you noted the rotor turning above until the light just comes on. This will put the engine roughly in time. Tighten the distributor clamp. Note the direction the rotor is pointing, the wire that emerges from the distributor cap there is number one. The plug wires should be installed in firing order starting with one where the rotor is pointing and continuing in the direction the rotor goes. The firing order is probably cast into the engine somewhere. I don't know it but there are only two possibilities 1 3 4 2 or 1 2 4 3. This should be enough to get the engine to run assuming compression and carburation are ok. After it runs you should reset the timing with a timing light and remove any jumper you may have installed to disable any protective system.
Good luck, call back if this doesnt help.
Bill