Before performing the test make sure to read the repair service provided with your outboard. How long the impeller will last if it has been manufactured and sits out its life on the shelf.
75hp 90hp 115hp 125hpLarger Optimax outboards run the same water pump as do M.
How to change water pump on mercury outboard. How to service and replace your water pump impeller on a mercury outboard. 75hp 90hp 115hp 125hpLarger Optimax outboards run the same water pump as do M. Slide the lower unit straight away from the outboard.
The water tube which moves water from the water pump to the rest of the motor will pull loose from the top of the pump housing on the top of the lower unit. Move the lower unit to the workbench. Place the unit into the vice so the drive shaft and shift rod point straight up.
How to Replace Your Mercury Outboard Water Impeller. Most Mercury outboards follow a similar design so the following guide will apply to most models. The next steps will guide you through the basics for a 60 hp Mercury outboard water pump replacement.
Socket 10mm for most models Parts. Apply a thread-locker to the threads on the pumps four bolts and thread the bolts into place. Torque the bolts to 50 pound-inches.
Apply white marine grease to a new water pump tube seal from the pump kit and push the seal into the recess in the water pump cover. Slide the water tube guide over the seal. Usually just the Impeller baseplate a gasket or two are needed but the kit often also includes a new base with new oil and water seals slinger washer and o-ring for the top of the driveshaft and instructions.
Usually its only a few more than the impeller and baseplate alone. Then up to 20-25 PSI at wide-open-throttle. This does change depending on the age RPM and model of outboard and impeller though.
If you are unsure how the outboard water pump is functioning it doesnt hurt to change the impeller. It should be changed often anyway and is the leading cause of water pump failure. Install the new water tube seal included in the water pump repair kit onto the water pump housing and youre done.
Replacing the water pump on a Mercury 40HP 2-stroke outboard engine is similar to changing the water pump on a 4-stroke. How to Replace Mercury 40HP Water Pump. Remove the rubber water tube seal from the top of the water pump assembly.
Separate the housing and slide it up the shaft. You can see in this picture that the bottom plate is coming off with it. We need to remove this plate also so if it stays stuck in place you may need to pry it up very carefully.
All in all the pump was in pretty good shape all the vanes on the impeller are intact. Although being labeled the father of Mercury Outboards its interesting that Kiekhaefer actually worked as a draftsman for Evinrude outboard motors in 1927 however was fired after just 3 months employment with Evinrude. Kiekhaefer had 3 unique qualities that made him less than the ideal employee 1 He had a keen eye to see inherent flaws in mechanical designs 2 He often.
Outboard motors are popular among motorboat enthusiasts because they are fuel efficient easy to maintain and virtually problem-free. However there are parts such as the water pump that will need to be replaced due to normal wear and tear. Water pumps keep the engine internals cool by circulating water through.
The impeller should run around 3040 and take about 25 minutes or so. When you look at the shelf life of the typical impeller it is typically listed as 10-15 years. How long the impeller will last if it has been manufactured and sits out its life on the shelf.
Of course your motors impeller needs to be changed regularly but its also a good idea to replace other components of your water pump to maintain proper engine cooling. Water pump kit contents vary so please take a look at the categories below and check the content of the kit you order. Items included may be an impeller wear plate impeller cups o-rings grommets mounting bolts pump.
How To Replace Mercury Outboard Water Pump Impeller. How to service and replace your water pump impeller on a mercury outboard. 75hp 90hp 115hp 125hpLarger Optimax outboards run the same water pump as do M.
The lower unit on Mercury outboards must be removed to change the water pumps impeller. Replacing the lower unit is part of replacing your water pumps impeller exchanging a drive shaft of one length for another length or replacing the oil seals on drive or propeller shafts. 70hp mercReplace water pump impeller.
Bear-Walker-Valv Thanks for the quick repliesexploded views and linksI have flooded the top of the drive sharft and bottom of shift sharft with CRCmade a slideing hammer from my weight lifting set and rechecked retaining boltsall out except one that is reached from the top of the drive sharft assembly housing. Before performing the test make sure to read the repair service provided with your outboard. The manual will guide you to select accurate specs and learn the exact procedures to follow to fix your fuel pumps issue.
First start the fuel pump testing by turning off the outboard engines power.