oil for 1980 70 hp Johnson

HI Guys,<br /><br />I have just finished fixing up a boat that has been sitting for 7 years. Had to free up steering (link was seized in tilt tube) and a few other bits and pices.<br />Motor fired straight up surprisingly. I know that oil/petrol mix is 50:1 but should I be checking case oil or gear oil ?? If so could someone let me know where I would check this (sorry I am a boating newbie)<br /><br />Also anyone know the type of spark plug and the gap as I might put in a new set, old ones look a bit ****y.<br /><br />Looking forward to taking boat out this sunday for maiden voyage after all the work. Cant wait !!!<br /><br />Cheers<br />Thanks in advance <br /><br />Brad

Re: oil for 1980 70 hp Johnson

Brad.... Spark plugs should be Champion QL77JC4 plugs, gapped at .040 .<br /><br />The oil mixture is indeed 50/1 (1pt of 50/1 oil to 6 gal gas) and a octane rating of 87 will be fine. Use a good quality oil that states the rating of "TCW-III".<br /><br />Yes, check the gearcase oil. There is a large regular slotted screw at the lower portion of the lower unit (the skeg). You will see another identical screw just above the cavitation plate (the plate just above the prop). The top screw is the oil level, the bottom screw being the drain and fill area.<br /><br />Use what is called "HiVis" gearcase oil. This is available at Wal*Mart, K-Mart etc at a reasonable price, and of course at your local dealership but at a higher cost. Fill from the bottom drain/fill hole until the oil flows out of the top oil level hole.

Re: oil for 1980 70 hp Johnson

Welcome to iboats.<br /><br />You'll want to use an outboard 2-stroke oil. Anything you get will be better than what was available in 1980, so don't sweat about using the most expensive stuff, although they are generally of better quality. I wouldn't necessarily advise looking for the cheapest stuff, however.<br /><br />Change your gearlube. The drain is at the bottom just above the fin that sticks down (skeg). The vent plug will be on the side just above the antiventilation plate and a bit below where it bolts to the midsection. Don't remove anything with a Phillips head. Fill it from the bottom until it comes out of the top. Then put the plug in the vent hole first and the drain hole last.<br /><br />Once you get it going, keep a close eye on the peeing water out of the back corner of the motor. The water pump impeller is old and really should be replaced. If the stream is strong, the pump is healthy. If it dribbles, you might need a new impeller. Even if it works good for awhile, the rubber has hardened over time and it could take awhile for it to fail.<br /><br />Good Luck and Happy Boating.

Re: oil for 1980 70 hp Johnson

Thanks heaps guys , I really appreciate it. If you are ever over this way (Australia) I will shout you a beer.<br /><br />Again thanks<br /><br />Brad

Re: oil for 1980 70 hp Johnson

Do I have to buy anything special to pump the oil in with or can I jury rig something up ?

Re: oil for 1980 70 hp Johnson

The lube in a tube.... you can squeeze the oil into the gearcase lower fill hole with no problem. Just be sure to insert the top screw back in the oil level hole to create a air pocket between tubes.

Re: oil for 1980 70 hp Johnson

Is that all I have to check on the engine. 2 stroke in the fuel and gear oil for the shaft ?