Re: 1967 johnson 6 hp preventive maintenance
Well, I hate to say it but it may be a big job since it hasn't been changed. Part of the reason to change your impelller so often is so that you can exercise the bolts and screws that hold it on, and regrease the driveshaft splines that habitually rust themselves into the crankshaft. This might not be such a big problem if you're not operating in salt.<br /><br />Normally it's a pretty simple operation - unbolt the lower unit, turn the driveshaft a bit to gain access the shift rod connector, disconnect that (completely remove the bolt) and remove the lower unit. Then remove the old water pump and install a new one. I think you're going to want to replace the entire water pump rather than just the impeller. The housing, etc, has got to be worn out.<br />Before replacement, grease the driveshaft splines and replace the o-ring on the splines if it's deteriorated. Put sealant on your water pump screws and lower unit bolts before installing them so they'll come out easily next time. Then just align the driveshaft, water tube and shift rod (reconnect), and bolt on the lower unit.<br />All these steps are illustrated in the service manual, which would be an excellent investment if your engine runs well. <br /><br />If the bolts are hard to turn, use PB Blaster (penetrating oil) and/or heat them up with a propane torch. You don't want to break them. A device known as an impact driver may help. This looks like an extra large screwdriver that you strike with a hammer.<br /><br /><br />Good luck! Sounds like a good project!
