Running a 2009 75hp Merc 4 stroke with big tiller handle.
Questions.
1. How hard is it to change the water pump? Preventative maintenance.
2. While running at WOT on plane, if I cut the throttle down to idle. The motor appears to want to kick out of gear but doesn’t full disengage. So it makes that grinding/clicking noise as if I was trying to put it in gear but didn’t put it fully into gear. Is this normal?
Wade, It almost sounds like your throttle on the tiller handle is out of adjustment…just a thought. Never done a water pump before.
The clicking noise is common on all 75-115 merc 4 strokes. It happens when you throttle down fast, the clutch releases the prop to allow it to slip or something along those lines. I have a BRAND NEW 90 4 stroke and asked the same questions, after researching I found it is nothing to worry about. Every time you throttle down faster than the prop can slow down it will do this from what I have found. If you try slowing the boat VERY VERY slowly it will not happen, but it has to be soooo very slow at least on my boat. I believe the waterpump is fairly easy, I also believe it is pretty cheap to have a shop do if you want to save time.
WPs are a cake walk, you tube it. There are slight differences by mfg but the process is pretty much the same. Its like changing oil on different cars.
As mentioned the click is the clutch in the LU slipping. The prop is spinning faster than the engine is spinning the gears in the LU. either come of plane slower or cut the throttle then drop it into neutral. I vote for slower off plane speed.
The water pump is a pretty easy process.
My advice for a 75 would be to have another guy there to help you, though. Sometimes getting the shift rod disconnected or getting the drive shaft splines to unstick from the coupling can be tricky and require an extra set of hands to support the lower unit.
IMO, it’s almost a necessity to have a second guy there when reassembling. It’s really fiddly and difficult to get the lower unit into place and then hold it steady while you connect the shift rod all by yourself.
Most outboards have a little trick somewhere in the process. It’s worth looking you YouTube to see if anyone has posted a video that shows the process with your outboard or one that’s reasonably close year-wise.
Be sure to use grease on the shaft splines. I also use anti-size compound on each of the lower unit retaining bolts when re-assembling. If any of those lower unit bolts gets corroded in place and breaks off, you’re in for a REAL beeaaaaach of a time getting them out.
Grouse
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