1973 Mercury 50 hp water output

[kclanier]

I just bought this boat. Runs great but no pee hole. Where does the water exit and how do I know if it is putting out enough. It does not appear to be running hot. Thank you

 

[jebeebe]

Re: 1973 Mercury 50 hp water output

If you take the hood off you should be able to follow the tube to the exit????????
I don't know that engine too well, but there should be a tube near the top of the block that comes down and exits through the cowl. If there isn't water coming out it doesn't nessesary
mean it is running hot, but it is not telling you it is getting water. Run a piece of weedwhacker line up in the tube. A mud dobber may have built a home in the tube

 

[Laddies]

Re: 1973 Mercury 50 hp water output

As you ck for the output as the other post says if it don't clean out, I think your engine is one that the telltale gets its water off the bottom of the exhaust manifold and they plug very easily so if it won't open there are a couple of fixes, one some powerheads have tapped and pluged port for a water pressure gauge on the top or on the cyl. block cover where you can hook it or have a marine mechanic drill the top of the powerhead we do it often.

 

[tmcalavy]

Re: 1973 Mercury 50 hp water output

This is a 73 Merc 500 right? If so, stand behind the outboard facing the bow of the boat. Telltale hole/hose should be on the right rear of the outboard, if memory serves the tube exits the case through the lower cowling/case. If it's not there, someone before you may have modified it. As said earlier, trace the tube and then clean it out with a small stiff wire or some weedwacker line. Even when it's free and clear you won't get much of a stream even with a new impeller at idle speed...should be some coming out but it won't really pee until you get the rpms up over 1200-1500. Out on the water at speed it should pee an easily visible stream. Best way to check the operating temp is to pull the top cover/cowl and see if you can touch the water jacket around the cylinders while it's running. Cool/warmish to the touch is okay...too hot to touch means you have some water pump maintenance to do. The driveshafts on those old Mercs get pitted with age. I had to have the shaft on my 72 Merc 500 built up and then turned back down by a machine shop...cost less than $100 at the time. The pitted shaft affects how much water the water pump can pump. That 72 Merc 500 was a real screamer and very reliable. Make sure your wiring under the cowl is sound, carbs are clean, timing is synched to carb/throttle advance, and the water pump/impeller are sound. If so, you should have a workhorse on your hands.