Does a 1963 mercury 650 have a tell tale?

[josht52302]

I have a '63 merc 650 4 cylinder. When i hook it up with muffs, i get water out of the prop, but i cant find a tell tale hole anywhere. The motor seems to stay nice and cool, but i want to be sure that all is good before i trust it out on the lake.

 

[Texasmark]

Re: Does a 1963 mercury 650 have a tell tale?

No! They came later when the old 2-4-6 cylinder "I" engines of the late 30's original design were replaced with lost foam casting where they reduced the number of cylinders for economy reasons, but added things like thermostats, over temp alarms, popoff valves, pee tubes, fuel enhancement vs a butterfly closing mechanical choke, oil injection, loop charging and on and on.

On current engines on the starboard (curb side, right from the rear looking forward) side of the lower cowling near the rear is the discharge hose. It is plumbed back to the engine to usually the exhaust manifold, the back of the block, or the outlet of the thermostat. If you had it the hose would be obvious.

I had a '75 70 hp once that blew a powerhead due to overheating. I drilled and pipe tapped a 1/8" hole in the rear of the water jacket, near where the spark plugs mount and installed a pipe to hose barb adapter, drilled a hole in the cowl where I said, added a hose and had my own pee stream.

HTH,
Mark

 

[GA_Boater]

Re: Does a 1963 mercury 650 have a tell tale?

Here's an easier way to add a tell tale.

On the top of the block between the flywheel and rear support there is a plug, item 11 in this breakdown Mercury Marine 650 (4 CYL.) CYLINDER BLOCK AND CRANKCASE ASSEMBLY Parts

Remove the plug and install an elbow, I forget the size, pointing to starboard with a hose across the block and down the side of the block. Route the hose so it doesn't interfere with the flywheel. On the lower cover that wraps between the driveshaft housing and lower cowl, there may be a tell tale barb on the lower starboard side, plug the hose onto the barb. If you don't have a tell tale barb, drill a hole and add a barb.

One of the advantages to using the plug on top of the block is eliminating a possible air pocket that allows the top cylinder to run hotter than the lower cylinders.

 

[josht52302]

Re: Does a 1963 mercury 650 have a tell tale?

Thanks for the help, i thought i was going crazy.