weak and very warm telltale at low RPMs

[nofishntx]

Just found this forum and it looks great.
Have a 84 50 hp Mercury that was sitting in the previous owners garage for about 6 years. After I bought it, the lower unit started leaking so I pull it and had it resealed. While it was off I figured this would be a good time to replace the water pump assembly and impeller. Checked the the telltale path in the head with trimmer line and then using a hose ran water through the water pump inlet in the bottom of the head and water flowed fine out of the telltale.
Everything back together and engine runs fine but when I start it up using the muffs get no telltale flow initially. Rev up to about 1500/1800 RMP and get a strong telltale but it is quite warm almost hot. Back down to idle and the stream becomes very weak almost stops.
Any ideas?

 

[ozziebob]

Re: weak and very warm telltale at low RPMs

Try it in the water. Leave it on the trailer tied on but run it backed into the water. Sometimes I have had problems with poor water flow( due to muffs or poor line pressure from tap) Just a suggestion to check the easy one first as I have been caught on some engine before from this.

 

[studlymandingo]

Re: weak and very warm telltale at low RPMs

Do you have a temperature or pressure gauge installed? This would be the best indicator of function. Replacing the impeller and pump assembly is always a good ide on a motor of unknown maintainence. I replace my impeller every season. The poppet valve and thermostat also contribute to the cooling system functionality; as long as everything was assembled properly in the lower unit, you'll need to look in the powerhead for other possible issues. Could be that nothing is wrong, I don't know how much pressure the tell-tale is supposed to have on a 50, but on my 150, the stream is always very warm.