We need the model number of that engine to know exactly what engine you have!
Never a good idea to buy a engine unless you hear it run, however, you've passed that point so just do the basics first such as:
The engine must crank over at least 300 rpm (pretty fast) in order to have the stator (under the flywheel) supply the proper AC voltage (approximately 300v) to the powerpack capcitor which is needed to energize the powerpack. A slow cranking engine will not be able to produce ignition/spark properly if at all.
1 - Remove all of the spark plugs and check the compression. What are the psi readings of all cylinders?
2 - With the s/plugs still removed, rig a spark tester where you can set a 7/16" gap for the spark to jump across. The spark should jump that gap with a strong blue lightning like flame... a real SNAP! Does it?
If no spark at all, disconnect the large RED electrical connector at the engine, then crank the engine by jumping the solenoid from the large battery cable terminal of the solenoid to the small 3/8" terminal that energizes it with a small jumper wire. If you now have spark with that RED plug disconnected BUT no spark with it connected, the cause is normally a shorted ignition switch.
You can use a poor mans spark tester by using a #2 philips screwdriver... stick the tip into the plug spring connector that is inside the rubber boot, then hold the shank of the screwdriver the 7/16" distance away from the powerhead.
Sitting for one year without running.... that normally results in the carburetors fouling, clogging, gumming up. If you have good compression and spark and the engine won't start of run properly, the carburetors will no doubt require cleaning and rebuilding.
The lower unit... Simply loosen the lower unit drain plug enough so that gearlube (or water if it exists) will be visible. If it is necessary to remove the drain plug screw, be ready to put it back in quickly if needed. If water or a milky looking substance exists... drain it all then refill from the bottom drain plug with "HiVis" lube until the lube flows from the top oil lever plug. If the gearcase lube looks normal, just top it off to make sure it's full for the time being.
Let us know in detail what you find.
well... as I come here to seek for help ! its a 88 Johnson spl about 150 hrs on the clock, the previous owner did not run the boat for about 1yr half prior to me buying it 2/26/14. he put about a 1g of fresh gas and tried to start with no luck? where can I start on getting this bad boy running any help will be appreciated thanks