Telltale help please

I am working on a 1970 Mercury 500 50 hp. I am looking for the telltale pee hole? There is a brass plug where I thought it was, when comparing it to my 1971 mercury 500 hp. I am in the process of transfering parts to the 1970 as the 1971 has a junk powerhead. Should I hook it up the same or is the pee hol in a different location?

Thanks

Re: Telltale help please

www.maxrules.com may be able to help

Re: Telltale help please

If you have a plug use it. Otherwise you can tap a 1/8 pipe thread in either the exhaust water jacket or the head water jacket in the general area of a spark plug and use a pipe thread to hose barb adapter. 1/8 dia hose is ok. Get the hose to match your hose barb diameter. You can drill a hole in the cowling if you don't have one and make it slightly larger than the hose. Then stick the hose through it and leave about 1/2 of the hose sticking out when you cut it off. If you want to know where to put it, just look on the right rear of other engines, in the lower (fixed) portion of the cowling. Idea is to put it where you can see it from the drivers seat which is usually on the starboard side be it tiller or wheel steering.

I don't know on that engine if it has a thermostat or not. If the 4 cylinder 50 it doesn't have one. Point is, tapping where I said will tell you your power head is getting water from the water pump. It doesn't say anything about the performance of a thermostat if it had one.

Mark