Re: 1971 evinrude 33hp ski twin ratchet wheel
You really want to have a service manual in hand for this. If you don't want to purchase one, you may be able to borrow one from the library. It won't answer all your questions, but it'll be an enormous help. We cannot cover all that's in it here.<br />But essentially, this is the procedure:<br />1) Disconnect the shift linkage behind the windown on the side of the midsection. Completely remove one of the two bolts.<br />2) Remove the 6 small bolts and 1 large bolt that holds the lower unit on.<br />3) Pull off the lower unit.<br />4) Remove the three screws holding the water pump housing on. Lift the water pump right up off the driveshaft. Careful not to lift up on the driveshaft or loose the impeller key if it comes loose.<br />5) Remove the impeller off the driveshaft. The driveshaft may need some cleaning.<br />6) Install a new impeller. It's not worth even thinking about the old one at this stage.<br />7) Coat all the threads of all your screws and bolts with sealer. This will make them easier to remove next time.<br />8) Install housing over impeller while turning the driveshaft clockwise so the vanes fit the housing. Screw it down<br />9) Regrease the splines at the end of the driveshaft.<br />10) Reinstall the lower unit lining up the driveshaft, the shift rod and coupler, and the water pump tube.<br />11) Make sure the shift rod connector is fully installed, and install the bolt you removed earlier from the coupler. Don't strip out the soft brass coupler.<br />12) Replace the window and test.<br /><br />If you did not operate the outboard in enough water to cover the seam between the lower unit and the midsection, the pump likely failed to prime. If the outboard was operated for more than a few seconds without water, the impeller has likely burnt up. If it shredded, it may have clogged things up down-stream. If so, try hose-clamping an old garden hose to the water tube and blowing out the obstructions with domestic water pressure.<br /><br />Hope this helps!