OMC 800, no spark, please help!

Hi, I am brand new the boating scene, and would like to thank everyone in advance for their help. I currently have a 1979 Larson 200 with an OMC 800 Drive. I recently purchased this boat with previous owner unable to start it. as of now I purchased new Sierra 18-8803 spark plug wires, and new ignition coil from NAPA auto. I have cranked the engine with a plug out, grounded, and with a timing light. What could i possibly be missing? When the ignition is on I get 10 volts at the coil +/- wires, but only ~ 1 volt when the coil is wired in.

I would have started with a complete tune-up kit as it's a new to you boat. That way you know those are fine. Coils get blamed all the time and VERY rarely are they the problem, high tension leads just as rare. Go get a points tune up kit for your dizzy, if it still has points, stick it in and set the points at .016 or dwell at 30-32 and you should be off and running.

Ok, Thanks! I will try that. My suspicion was that the wiring from the distributor or the points/condenser are the issue also I only have one wire leaving the distributor into the wire loom, is that correct? I have a Mallory YL624JV I found the tune up kit ~ $29 CAD + shipping (http://www.sterndrive.info/id120.html). Now I agree with you 100% that the distributor needs a tune up, but i do not have a tool to set dwell, and no small feeler gauge. What are your experiences with the electronic conversion kit? as the cost may be similar to the points tune up and tools.

If you only have one wire from the dizzy, you still have points. That wire will go to the negative side of the coil along with another wire that is the tach wire. The positive side of the coil gets the ignition wire from the key switch and the bypass wire from the start solenoid. Just get a cheap set of feeler gauges and set them at .016 and don't worry about dwell for now. You should be able to get the tune-up parts at a auto parts store, there's nothing special about them, just take the dizzy number and the old parts and they'll match them. Tell them it's a Mallory

Getting spark now!! Thank you so much for your help! I began by adjusting the point gap on the current dizzy, it was out at 0.022, set gap to 0.016 and got spark. Just ran to my local marine shop this morning and picked up condensor, points, and rotor to replace this afternoon. Just wanted to say thanks again!

If you get it going, be sure that you run it TIED UP AT THE DOCK for a good long while, running thru the gears. Do not take an unknown boat out on the water, until you are sure all the bugs are worked out.

o2batsea said:

If you get it going, be sure that you run it TIED UP AT THE DOCK for a good long while, running thru the gears. Do not take an unknown boat out on the water, until you are sure all the bugs are worked out.

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I don't even take them off the trailer. Go to the ramp when it's not busy and run it in the water still tied down. Warm it up and go thru the gears several times and then try and push the whole mess up the ramp in forward gear, that will tell you lots of things.

Ive been trying to start it at home with the hose hooked up to the drive. Is this the correct method?... also i have not had time to work on the boat since i replaced the points, condensor, and rotor.... cap is on order.

OK, checked everything today and gave it a crank turned over and then...... engine seized. Either my oil pump is dead or never made enough pressure to lube the bearings. It has been turning over for the past week trying to get spark and fuel. now have both. Today I'm going to pull the engine and check out the bearings. Thanks everyone for all your advice. I will hopefully throw some new bearings, and oil pump, lots of assembly lube and hopefully get it on the water before our summer weather hits!