Re: 1958 18 HP Johnson powerhead removal

[chas56x]

To remove the power head, you will have to remove 7 bolts/screws and two nuts from the studs on the front of the power head. It is easier to get to those nuts if you first remove the pan sections. You don’t have to remove the flywheel or carburetor to remove the power head. If you are using the 2 line fuel/air system, you will have to remove the fuel and air hoses from the fuel connector. You will also have to disconnect the tower shaft that attaches to the magneto plate advance arm. When removing the shift arm, be careful not to drop any screws or washers as you will have to drop the lower unit to fish them out. This would also be a good time to remove the shift lever from the exhaust tower and clean up the pivot shaft, and apply a nice coat of waterproof grease to the shaft. Now would be a good time to make sure the small spring is present in the small hole on the inside flange of the shift lever. If it is missing or worn down, now would be a good time to replace it with a new one. Before reinstalling the power head, coat the top drive shaft splines with a coat of waterproof grease as well. With the power head removed, it is also a good chance to clean out the water cooling jackets, blow compressed air through the cooling passages and put on a new power head gasket. When dropping the power head in place, it may be necessary to rotate the flywheel to line up the drive shaft splines with the crankshaft splines. You do not need to coat the power head gasket with any sealer. Have fun.