Boat Engine Year

We have a Mercury Inline Outboard 115 HP....6 cylinder engine...Serial number 5488608. Anyone tell me what year this is. I read somewhere that it could be a 1979? Do you have to mix gas and oil?

Re: Boat Engine Year

well according to this it is a 1979 115 5168574 - 5600966 1979 as its in between those numbers and yes you mix it 50;1 gas and oil

Re: Boat Engine Year

Thanks!!!!
We have no spark at the plug. What could be causing this. Any ideas? We can not get the engine to start.

Re: Boat Engine Year

could be a couple of things, bad coil, switch box, broken wires as is common on old mercs. I use a volt/ohm meter to chase the wires and voltage and usually fire it out with little problem. By using an analog volt meter you can see if you have a pulse voltage going from the switch box to the coil(s). You should have a continuous voltage going to the switch box. If it has a distributor the distributor will operate similarly to the switch box. If you've got good voltage going to the distributor (12 volts) then you should have a pulsing voltage coming from it to the coil. This will be a high voltage. The coil will amplify this voltage, return it to the coil, and the rotor button will distribute it to the plug wire electrodes. Just make sure you've got spark/voltage when when the points (contacts) inside the distributor open. I usually just check this with a screw driver by opening the points with the screw driver and looking for an electrical arc. Sometimes all you need is to clean the points to get it going, This can be done with a finger nail file, fine sand paper, or emery cloth. The points should be reset at .020 inch.

Re: Boat Engine Year

Check each plug to see if you have any of them sparking Pull 1 out at a time and with the plug wire attached hold close to your moter and have someone else turn the keythis will let you know which one's have spark and which ones don't Now if you have spark to at last 1 plug try moveing some wires from coil to coil to eliminate good from bad. But if none spark you have a bigger problem and if your not motor wise it's best to have it looked at as this can save alot of money replaceing parts you don't need