water pick up

[Justlakinit]

Can you provide me a diagram of how the water pick up line in the out drive is replaced.
I am having water flow issues and am wanting to replace the pick up hose as well as all the other water cooling lines.

Eng. No. OF601305
Drive No. OF693057

[admin]

I need a little more clarification. Do you mean the water hose that runs from the outside bellhousing to the gimbal housing? What issue are you having? Have you replaced the impeller yet? That is the place to start anytime you are having cooling issues.

Tech Support

[Justlakinit]

Yes that is the hose I am talking about.
I try to explain my issues in a short version.
I am on my 2nd replacement motor.
The original motor never got hot on the temp gauge, but burned a hole between cylinders 3 & 5.
2nd motor lasted for 2 years....never showed hot on the gauge, but blew head gasket and hydro locked...cracking head and block between cylinders 2 & 4.
I don't run it hard at all, but I have been told that it sounds like I am getting air in my water flow which is causing air pockets in the middle cylinders causing them to get hot and crack, but I am getting enough water flow to cause the temp gauge to act normal.
Just put in my 2nd replacement motor....took it out last weekend and ran it very easy....mostly cruising below 30 mph and approx. 3000 rpm. Water temp good and oil pressure good. Ran it that way on several 10 mile trips trying to break in the new motor.
The next day, I ran it for a while in the same manner, then increased the speed to approx. 35 to 40 and shortly afterwards the motor started getting sluggish and as soon as I got off the throttle the temp shot up to over 220 and the oil pressure dropped and the alarms went off and the engine shut down. I was able to let it cool and drive back to the dock at low speed with no issues.
The next day I took it out again...all was good at low speeds, even on long runs, but if I get much over 3000 rpm the temp goes up and the oil pressure drops.
This is completely rebuilt long block from engine company, new water circulation pump, complete impeller rebuilt kit, including friction plate, and housing. I flushed all hoses and checked for condition before installing the new motor.
Only thing that I can think of is that he hoses are older and are creating an issue of some sort. Everything else is new so I am out of ideas.

[Justlakinit]

Any advice on changing this pick up tube/hose?

[admin]

I don't think your hose is the problem, It is most likely the water pump not sealing properly to the case which is allowing it to suck air. A pretty common issue. You need to make sure the case is smooth and flat at the mounting surface, and then I would recommend using a little silicone sealant around the pump housing, especially at the rear.

The test for this is to replace the water hose in the boat with clear hose, and then watch it as your running the boat. It should look good below 3,000 rpm or so, and then above 3,000 you will see bubbles. The only way for bubbles to show up is from air being sucked in.

If you want to change the hose, you really just need to buy a bellows kit and replace everything since it all has to be removed to access the hose. I would recommend purchasing a manual if you wanted to attempt that job yourself, and you will also need some special tools

Tech Support

[Justlakinit]

when you say to make sure the case is smooth and flat at the mounting surface and to use silicone...are you referring to the actual housing of the impeller?
Thanks for the reply...this makes a little more sense.

[admin]

I am talking about the actual aluminum lower unit case. The stainless steel housing of the water pump should be fine.

Tech Support

[Justlakinit]

I am going to try this test this weekend, but I am curious how air can enter at the point you are referring to (where the lower unit meets the upper unit) when this is submerged under water.

[admin]

On plane, this is most likely not submerged depending on the boat. The engine sucking in a lot of air, the air is getting exhausted through the drive, so it is introducing air into that area.

Tech Support