I have a 2006 Mercury 115Hp EFI 4-Stroke. It has run GREAT since I bought it, I've never had any problems with it!
The other day when I was at the lake, I beached the boat on a sand bar while we were camping. To make a long story short, I think the water pump possibly sucked up some sand/dirt...
When I went to put the boat back on the trailer, I noticed the engine wasn't discharging water from the tell tale.
When I got home I took the "T" apart behind the tell tale and sprayed 100 PSI air threw all 3 tubes, the tube going out the tell tale discharge was clear, the tube going down to the water pump was clear (I heard air come out), the line that goes to the vertical "Fuel/Water" bar (Fuel Cooler?) on the left side of the engine block, then on around to the engine itself must be clogged because when I put air to it, I couln't hear any air coming out anywhere and the tube blew off the air gun..
But what really gets me is that even if that was clogged, I should see water coming out the tell tale because of that "T". If the rest of the system was clogged, the water would atleast come from the water pump and go straight out the tell tale..
Once the water goes into the engine, I couln't figure out where it came out??
This concerns me that I might need a new water pump. I changed the water pump on an Old '79 Mercury 40HP 2-stroke, it wasn't too hard, but trying it on this 115Hp kind of scares me. Can anyone tell me how difficult it is to do?
Looks like from the service manual just 4-screws on the lower unit and it should drop out? Does the drive shaft come out with it like it did on the '79 2-stoke?
On another note, It's 4 years old now and while I don't have any problems, I thought I should probably change the spark plugs, I know they are NGK LFR6A's. Should i stick with the NGK's or is there a better plug out there I should use instead?
Thanks for the help!