I just purchased a decent 1978 Johnson 6 hp. It appears to run pretty good. The water is coming out of the pee hole good. It has not been run in several years until I got it, just sitting in a garage. I plan on using it a fair bit fishing. I've read several places to replace the impeller, as one of the first maintenance tasks, especially with motors that have sat awhile. (I've also read where replacing the impeller is very easy ;-)
Based on that advice, I purchased a water pump kit and my plan was to replace that "easy" impeller. Simple right....? I purchased the Johnson 1978 6hp service manual and perused the instructions and nice pictures. To my surprize, the procedure for replacing the impeller is fairly extensive. It's removing most of the components of the upper motor / power head. I'm fairly mechanically inclined, but I'm afraid if I do all these steps, it'll never work the same. The manual is good, but it leaves much to be desired on some of the steps. Is there an easier way than the manual instructions? Any help or shortcuts, tips, hints or any pictures / video / youtube of this task would be greatly appreciated (Pictures of a Johnson impeller replacement job would be wonderful). Thanks Terry
Here's "some" of the instructions from the manual.
Under removal of Gear case: (It doesn't specifically say to remove the powerhead but I'm assuming you do).
a. Remove upper motor cover, and disconnect spark plug wires.
b. Place gear shift in reverse position.
c. Remove four screws attaching gearcase assembly to gearcase extension or exhaust housing.
d. Rotate propeller to align seal support pin in drivershaft with slot in exhaust housing.
e. Lower gearcase sufficiently to expose shift rod connector.
f. Remove gearcase assembly for exhaust housing or gearcase extension.
Under removal of powerhead
a. Remove carburetor, leaf value assembly, fuel pump and filter, and fuel hoses as described in section 3.
b. Remove flywheel and ignition component as described in section 4. Remove starter as described in Section 7.
c. Remove throttle control level by removing two screws and clamp, and lifting lever from lower motor cover.
d. Remove water pump indicator hose.
e. Remove seven screws attaching power head to exhaust housing assembly.
Based on that advice, I purchased a water pump kit and my plan was to replace that "easy" impeller. Simple right....? I purchased the Johnson 1978 6hp service manual and perused the instructions and nice pictures. To my surprize, the procedure for replacing the impeller is fairly extensive. It's removing most of the components of the upper motor / power head. I'm fairly mechanically inclined, but I'm afraid if I do all these steps, it'll never work the same. The manual is good, but it leaves much to be desired on some of the steps. Is there an easier way than the manual instructions? Any help or shortcuts, tips, hints or any pictures / video / youtube of this task would be greatly appreciated (Pictures of a Johnson impeller replacement job would be wonderful). Thanks Terry
Here's "some" of the instructions from the manual.
Under removal of Gear case: (It doesn't specifically say to remove the powerhead but I'm assuming you do).
a. Remove upper motor cover, and disconnect spark plug wires.
b. Place gear shift in reverse position.
c. Remove four screws attaching gearcase assembly to gearcase extension or exhaust housing.
d. Rotate propeller to align seal support pin in drivershaft with slot in exhaust housing.
e. Lower gearcase sufficiently to expose shift rod connector.
f. Remove gearcase assembly for exhaust housing or gearcase extension.
Under removal of powerhead
a. Remove carburetor, leaf value assembly, fuel pump and filter, and fuel hoses as described in section 3.
b. Remove flywheel and ignition component as described in section 4. Remove starter as described in Section 7.
c. Remove throttle control level by removing two screws and clamp, and lifting lever from lower motor cover.
d. Remove water pump indicator hose.
e. Remove seven screws attaching power head to exhaust housing assembly.