poor water flow problem from Tell-Tale - 1985 I6 115hp Mercury

[V20Pilot]

OK fellow sailors, my water flow problem continues. After a new impeller, impeller housing, and cleanout of the water jacket I still have low water flow from the Tell-Tale. On start up it takes about 30 seconds to start flowing and then it never gives a consistent flow. I did buy a low pressure water gauge to check the pressure. I have to find the right brass fitting/adapter to do the install on that this afternoon.

So where do a look from here for a source for bad pressure? Maybe the metal tube from the impeller housing to the block?

Steve:facepalm:

 

[V20Pilot]

Re: poor water flow problem from Tell-Tale - 1985 I6 115hp Mercury

OK, I think I might have something figured out. I'll try this out this afternoon when I get home. I searched on line for the impeller kit that I bought. These photos show the housing the kit I bought. One shows the base too.
and
One image shows a rubber grommet/seal right next to the impeller and the water tube and the other one shows it sitting inside of a large o-ring. Is this part the same as part #18-3110 (Sierra) and 26-38970 (Quicksilver)? And is this used to seal the white plastic tube to the metal tube that rises up to the block? When I took the LU apart there was no seal between these two tubes. I'm thinking maybe this is why I don't have sufficient pressure to have the water rise up far enough to flow properly out the telltale. Looking at this part on the marine.com site it looks different though. Or is this rubber seal not included with this kit?Sierra Marine 18-3110 - Seal, 26-38970 @ MarineEngine.com

I'll try putting the pressure gauge on first but if the pressure is low which I'm sure it will be, I'm going to drop the lower unit and try to seal this up with the grommet or even some red hi-temp RTV. I'll let you know how I make out. I've ordered the 18-3110 seal from the local West Marine. They said about a week.

 

[capttwb136]

Re: poor water flow problem from Tell-Tale - 1985 I6 115hp Mercury

Check your thermostat. They can get clogged with debris and stuck which affects the pee hole flow. I replaced my impeller because of a weak flow and like you saw no improvement. Was advised to check thermostat, sure enough it was clogged and stuck. Clean it, put it in a pan of water, heated the water to boiling, would not open. Bought new one, put it in, pee hole flow 3 times as strong.

 

[Chris1956]

Re: poor water flow problem from Tell-Tale - 1985 I6 115hp Mercury

I doubt there is a thermostat on that motor.

Is there water exiting from the gratings above the antiventilation plate? If so, you do have some circulation. You can stick the pressure gauge in place of the telltale elbow. Expect to see a few PSI at idle and maybe 7-10 PSI at high speed.

 

[schematic]

Re: poor water flow problem from Tell-Tale - 1985 I6 115hp Mercury

Is this part the same as part #18-3110 (Sierra) and 26-38970 (Quicksilver)? And is this used to seal the white plastic tube to the metal tube that rises up to the block?

no, the grommet you speak of goes on the driveshaft and sits on top of the pump housing

is this used to seal the white plastic tube to the metal tube that rises up to the block? When I took the LU apart there was no seal between these two tubes. I'm thinking maybe this is why I don't have sufficient pressure to have the water rise up far enough to flow properly out the telltale. Looking at this part on the marine.com site it looks different though. Or is this rubber seal not included with this kit?
I'll try putting the pressure gauge on first but if the pressure is low which I'm sure it will be, I'm going to drop the lower unit and try to seal this up with the grommet or even some red hi-temp RTV. I'll let you know how I make out. I've ordered the 18-3110 seal from the local West Marine. They said about a week.

the grommet you ordered is usually supplied in the kit. if you look at your images you can see its already installed. it usually comes installed. if its missing, it certainly will drop pressure.
don't be using any silicone as its not needed and may flake off and plug things down the line.....

 

[V20Pilot]

Re: poor water flow problem from Tell-Tale - 1985 I6 115hp Mercury

Check your thermostat. They can get clogged with debris and stuck which affects the pee hole flow. I replaced my impeller because of a weak flow and like you saw no improvement. Was advised to check thermostat, sure enough it was clogged and stuck. Clean it, put it in a pan of water, heated the water to boiling, would not open. Bought new one, put it in, pee hole flow 3 times as strong.

This model has no thermostat. Already been down that road.