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Did a teardown; put new rings and crankcase seals among a few other things. Was able to get it to fire on starting fluid, then ran it for ten minutes on fuel mixture with the muffs on. It fails to start on fuel and oil mix, but will start with some help then stay running. Any ideas???? I'm sure there is a long list to check. I have spark and am getting fuel (it seems) but failure to ignite!
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(Compression & Spark Test)
(J. Reeves)
1st - Regardless of what problem one might encounter, always start with the basic troubleshooting procedure. Check the compression which should be in the range of 100+ psi (somewhat less on the smaller hp engines) and even on all cylinders.
2nd - With the spark plugs removed, rig up some type of spark tester whereas you can set a gap to be jumped. On magneto ignition systems.... and also the Battery Capacitance Ignition system OMC engines from 1968 to 1972, set the gap to 1/4". On the solid state OMC ignition systems from 1973 to the present, set the gap to 7/16". The spark should jump the gap with a strong blue lightning like flame..... a real strong blue snap!
NOTE: Checking the spark via using the spark plugs is a waste of time and proves nothing. The above stated gaps must be used for a proper test.
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(Spark Tester - Home Made)
(J. Reeves)
You can use a medium size philips screwdriver (#2 I believe) inserted into the spark plug boot spring connector, then hold the screwdriver shank approximately 7/16" away from the block to check the spark or build the following:
A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.
Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:
..........X1..........X2
.................X..(grd)
..........X3..........X4
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(Proper Starting Method - Fuel Primer Solenoid - Choke Butterflies)
(J. Reeves)
Cold Engine: Pump fuel primer bulb up hard. Increase throttle somewhat with whatever type control you might have UNLESS your engine is equipped with the "Fast Start" feature. Turn key to start position. As engine cranks over, push in key to activate the fuel primer solenoid OR to close the choke butterfly(s). (Fuel is drawn into the crankcase with every upward stroke of the pistons).When engine fires/starts, release the key. Should engine start to die out, push key in (just a tap) as needed to activate primer solenoid OR choke butterfly(s) in order to momentatily increase the fuel flow.
Warm engine: Pump fuel primer bulb up hard. Turn key to start position. When engine fires/starts, release the key. If engine does not fire/start within 6 revolutions, push in key to activate fuel primer solenoid OR choke butterfly(s) as needed.
This is assuming that the engine is as it should be in all respects (Compression, Ignition, Carburetion, Fuel Supply, etc).
NOTE: Many boaters with the engines incorporating the "Fuel Primer Solenoid" use a method to start their "cold" engine(s) whereas they pressurize their fuel primer bulb, then without cranking the engine over (Key ON), they push in the key to energize the fuel primer solenoid. This allows the pressurized fuel line to have fuel flowing directly into the intake manifold area... a puddle of fuel mixture sitting there waiting to be drawn in as soon as the engine cranks over. Many swear by this method... a matter of choice, opinion, whatever. However, what OMC originally recommended is as you see stated above this paragraph... but then again... whatever works for you.
Engines incorporating the older choke butterfly setup..... Of course, with the engine NOT running but with the key in the ON position, pushing the key in to activate the choke results in closing the butterfly (butterflies) but does absolutely nothing other then to verify that the choke assembly is operational. The engine must of course be cranking over to create the needed vacuum to drawn the fuel into the crankcase.
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