Mercury 500 50hp water pump

[Thunderboltmerc1992]

I have a problem. I cannot figure out where the tell tale is supposed to come out of my engine. The place where it is supposed to be hooked up is not, and before I install a new water pump impeller and hose to the tell tale, I would like to check for dauber nests or trash.

 

[carholme]

Re: Mercury 500 50hp water pump

What is your engine s/n?

Here is a picture of a 1975 block and you will see item 11, plastic fitting which fits in the lower LH, just to the left and a bit lower than the lowest sparkplug. The a hose is connected to it and runs around to the RH aft side of the lower cowling.

Mercury, Mercruiser, Force, etc. - CYLINDER BLOCK AND CRANKCASE ASSEMBLY - MERC 500

Gerry

 

[Thunderboltmerc1992]

Re: Mercury 500 50hp water pump

Serial number is 3482516.

 

[carholme]

Re: Mercury 500 50hp water pump

That s/n comes up as:

50 500 4-cyl 3478003 3816307 1973 USA

From here:

Mercury 2-takt, 4-cyl, 40 - 85 hp, produktions?r, modellguide

Parts List:

MERC 500 - Mercury, Mercruiser, Force, etc. Parts Lookup

You will see under CYLINDER BLOCK AND CRANKCASE ASSEMBLY that it is the same setup as in my previous post #2.

Gerry

 

[Laddies]

Re: Mercury 500 50hp water pump

If you want to repair the telltale properly on any engine that has the telltale hose coming from under the exhaust cover, first check on the top of the powerhead and you should see a 1/8 pipe plug put a elbow in the hole and route a new hose to the pan fitting, this will stop any steam dome from forming in the powerhead water jacket all newer enginer were built this way. Now you need to plug the old fitting, some you can reach and can remove the old fitting and put a plug in the hole some you cannot reach so the simple thing to do is cut the hose put a plug in it and hide it in the bottom cowl.

 

[carholme]

Re: Mercury 500 50hp water pump

You can see the plug as item 4 under CYLINDER BLOCK AND CRANKCASE ASSEMBLY and yes, that is where you will see the newer one but I have four engines here running the old style since they were built in the late 60s without a problem.

Gerry

 

[Laddies]

Re: Mercury 500 50hp water pump

There are 1000s, maybe 10,000s 44cu.in. Mercury engines out there that have not been converted but when someone is having problems with the telltale not working, why would any mechanic professional or otherwise not want to fix the troublesome engine properly.