Stinger water pressure issue

[sharpeye Mike]

So last fall, I lost water pressure in my Stinger, no problem, I replaced the impellor this spring but the pressure never came back up so I took it apart in case I mite of messed up, every thing seemed ok, checked power head base bolts, also tight, blew the pressure gauge hose out with the compressor, tried new gauge, replace the lower unit and pump from my spare, same thing. This motor is stock except for the .020` over pistons, it has about 35 to 40 hours since rebuilt.
What do I check next? :confused:
Mike

[75luva]

Did the impeller break any blades (peices off)?
If so did you make up the impeller with the bits before fitting new impeller
A peice could be stuck in the colling passage of the engine/base plate

[sharpeye Mike]

The guy I bought it from fried the impellor and pump housing, the impellor was in pieces and partially melted but that was 4 years ago and this motor was rebuilt from power head to lower unit since then, I guess a piece could of lodged in the block never to cause me problem till now. I ran it a couple of hours without any issues but this is a really good running motor and I hate to kill it this way from a hot spot. Beside the base plate where else could it be lodge to lower my pressure?
Thanks, Mike

[Powerabout]

lower unit off
garden hose on the water tube and see if you can get the pressure back that you had.

[sharpeye Mike]

lower unit off
garden hose on the water tube and see if you can get the pressure back that you had.

Will try tomorrow, our city pressure is around 65 lbs., this should be interesting, good call, let you know what happens.
Thanks.

[Powerabout]

Will try tomorrow, our city pressure is around 65 lbs., this should be interesting, good call, let you know what happens.
Thanks.
Just push the hose on the water tube so it will blow off if there is a big restriction, 65lbs might be dangerous
15-20 is safe.
Where in the engine is your water pressure gauge plumbed?
I would also start with removing the thermo and pressure relief valves and see that the water comes out of there easily with the cover off..
This will basically check there is not a restriction to the powerhead.
Highly unlikely there is a restriction after that.

[sharpeye Mike]

Did it, done it, not sure what I was expecting, I guess maybe chunks of rubber was going to fall to the floor lol.
Lots of water come out of the stat and relief valves, pressure gauge wasn't sowing more then 5 lbs. after I bolted up the stat cover though, although I couldn't believe how much water comes out of the mid.
P.S. pressure gauge is tap into the pisser just before it leaves the cowl, always been that way on this motor.
Thanks for the replies guys.
Mike

[champ20B]

Did it, done it, not sure what I was expecting, I guess maybe chunks of rubber was going to fall to the floor lol.
Lots of water come out of the stat and relief valves, pressure gauge wasn't sowing more then 5 lbs. after I bolted up the stat cover though, although I couldn't believe how much water comes out of the mid.
P.S. pressure gauge is tap into the pisser just before it leaves the cowl, always been that way on this motor.
Thanks for the replies guys.
Mike

This is not uncommon with old motors when restoring.....I have seen this especially with old Kiekhaefer mercs as they were made of cheap corrosion prone aluminum. Oxide would build and loosen and settle in the passages hardening like cement and block water. Sometimes mud would get in the pickup or a dirt-dobbler would build a nest in other types of motors. Oxide build-up is why the pistons in those green mercs often had scalded pistons on one side or other. That's only one reason I quit messing with them.

Now as for your Stinger outboard, here is what I always did with my mercs:

I would build up the water pump. I make sure it is properly sealed. I then take the gearcase and put it in water (tub or bucket). I make a drive shaft adapter with tough hose and clamps about 3" long. One end to top of drive shaft and other over socket of similar diameter driven by rechargeable battery drill. Don't use an A/C drill for this. I spin the shaft to see the pump shoot up water. I then blow through the mid section water tube (powerhead removed). If it is clear, I go to the powerhead. I check the inlet hole, and the outlet of the engine. I check the exhaust water jackets. If they are clear, I check the block water jackets removing the cylinder head or cover. You are bound to find the trouble. Always check for good gasket contacts (seal) throughout the system as well when you reassemble. That's all there is to it......

[Powerabout]

as you have the omc idea of pressure gauge in the pisser hose, how does it read if you place your finger over the pisser when running the engine?

[Seagull 170]

Too much water coming out of mid?

[Powerabout]

Could be....
Corroded out adapter lets water skip the powerhead

[sharpeye Mike]

This is a fresh water motor, rebuilt 3 1/2 years ago, rebuilt lower unit, all gaskets and o rings replaced including base plate and exhaust chest. I have two 15'" motors, one in pieces at the moment so I swapped the gear case with a fresh water pump, no change. I have 3 boats and 1 spare 20" motor, why so many boats? Addiction I guess, summer is short in Canada and I'm busy with work, projects and other chores, not complaining, just saying lol, just trying to avoid tearing it apart that's all. I think pulling the power head off the base is going to be my next step when I get the time.
Thanks again guys.
Mike

[Powerabout]

we are not chasing a water pressure gauge that doesn't read like it used to are we?

[sharpeye Mike]

we are not chasing a water pressure gauge that doesn't read like it used to are we?

No sir, tried a knew one before I got to far into this, not sure but I think the stream coming from the pisser running at w.o.t. is not quite at par also.
Thanks for the reply Powerabout
Mike

[Powerabout]

No sir, tried a knew one before I got to far into this, not sure but I think the stream coming from the pisser running at w.o.t. is not quite at par also.
Thanks for the reply Powerabout
Mike
Ok
have you tried the pressure with your finger on the pisser to block it?
If the pisser is partially blocked at the powerhead then the volume will lower the pressure on your gauge with that set up
How about with garden hose up the pipe, clearly that should create tons of pressure..
If you cant get pressure like that I would be looking at the adapter plate

[Popa Sam]

Is the plastic screen in water pick up in it's proper place? If loose, water pump pressure will pull it up and close off water pick up.

[sharpeye Mike]

Ok
have you tried the pressure with your finger on the pisser to block it?
If the pisser is partially blocked at the powerhead then the volume will lower the pressure on your gauge with that set up
How about with garden hose up the pipe, clearly that should create tons of pressure..
If you cant get pressure like that I would be looking at the adapter plate

Hey Powerabout, yes I tried the finger on the pisser, It goes up about 2.5 lbs. and I blew the gauge hose with an air compressor before with no difference, I ran the hose on the tube but still showing about 4 to 5 lbs., ran it on the muffs, no difference. I think I will lift the power head off the base and investigate this deeper as soon as I get a bit of free time but what I should do is finish my 56 cube Stinger then I would a spare motor. Ah to many projects so little time.
Mike

[sharpeye Mike]

Is the plastic screen in water pick up in it's proper place? If loose, water pump pressure will pull it up and close off water pick up.

Hey Popa Sam, screen is intact, I also tried my other nitro case on this motor without any difference.
Mike

[sharpeye Mike]

Not feeling at par these few day, flue like symptoms. Today I got cabin fever so went into the garage and got my hands dirty, tore the power head off, the base plate and exhaust can off, inspected the gaskets, water tube and water channels, didn't find anything so I cleaned her up and replaced the gaskets. Next the power head, took the head, water jacket and thermostat cover off, inspected, again nothing there. After that I took the exhaust plates apart inspected the gaskets and water channels, again nothing there, then it dawned on me, its the damn Gremlins, ya that's it, Gremlins. I ordered the rest of my gaskets that I was missing today, will be putting the rest back together next weekend, let you know what happens.
Mike

[Powerabout]

While it is apart you might want to drill and tap a top of engine location for the pisser and fit the gauge where the pisser was.
Pisser at top just helps vent any air

[sharpeye Mike]

Will do Powerabout.

[sharpeye Mike]

Looks like I will have to wait till next week, one of the exhaust plate gaskets was back ordered, I know for sure if the gasket is not in by next Friday, I will put a 56" block on the Stinger mid.