low water flow out of water out hole(ahelp please)

[ronnyd8719]

I have a Mercury 115 inline six. I have now taken it down to rebuild, but before I took it down I had little water flow. I changed the impeller and still at idle the water drained slow. While I have it down would anyone be able to tell me if I should check something out or do the inline six just have a lower water pressure than most. I have a temp gauge and it runs at 160 F . So the temp is not a big problem. I am worried the lack of water can cause harm. I was not going to take down the water jacket off from around the plugs. Should I check this out are there should not ge a problem in there. Any help woudl be thankful.
Help PLease
Ron

[Techno]

Even at idle there should be a good piss stream out of the hose.
Since your taking it apart you might as well. This cover only covers the cylinders and is only a water cover. It could be filled with sand though.

If I remember the side cover, on the right also has something to do with this. I broke a bolt here and lost water pressure, this was quite apparent since it leaked out..

The impellor also should be wrapped backwards, the vanes should wrap backwards and not forwards. Besides this the housing could be worn or cracked but its usually the impellor.
Also if you start your engine out of water, dry, then the impellor is cooked in several seconds so is no longer a new impellor.

[Jay Smith]

Was water presure high along with weak tell tale? If so could be water pump system health and or restriction on spent water leaving block. I asked the question about the pressure if its high look for the pump to be OK and there would be a suspect blockage and or a restriction SOMEWHERE in the spent water leaving the block....

Good luck,

[The Big Al]

Trash, trash, trash in the ta-tail hose or nipple.

[ronnyd8719]

I ramped a hanger though the hose and no dirt and anything. I am thinking so taking off the water jacket. That is the only place I can see.
Thanks Ron

[sosmerc]

As long as you are taking the trouble to tear it down, why not remove ALL covers and inspect the passages? (including the inner water jacket cover)
A healthy inline 6 should show a strong stream out the pee hole at all times.
I don't know where you were checking temperature, but from my experience, these engines run pretty cool anywhere on the block. (they do not use any kind of thermostat or pressure control system such as a poppet valve)
With the powerhead off, be sure to check the condition of the water tube up where it enters the exhaust adapter plate...it could be crushed from salt expansion around the rubber grommet...or it could be corroded badly and have a leak in that area.

[blfink]

I have an 1985 115 inline six with a water gauge hookup on the dash. My "tale-tell" hose has a nice little stream at all times but at idle I don't see water pressure on the gauge. At WOt I only see 5-6 psi. The Merc dealer around here says thats what he would expect for that motor. He said the pressure varies with engine rpm and will max out at 5 - 6 psi. Do you all agree with that?

[sosmerc]

I would agree with that, although on some boats that can run above 50mph you will probably see pressure near 10 PSI.
The key is, always put in a new Merc Impeller 89984T4 EVERY season. Replace the gaskets on either side of the wearplate also.

[brotherxb03]

They have a inner exaust water jacket plate on there too that should be gone through too. I remember I brother changing many at his shop and having to true up many new plates before install or they will leak.