No visible cooling water flow at high speed

[pelletman]

Just put a replacement lower unit on my 1990 120 horse. Everything seems fine except that I do not
see any water exiting the lower leg during high speed. At lower speeds, it appears as if there are two
hoses exiting the unit. (plenty of flow). Is this normal ? Replaced the impeller at the same time as
the lower unit. Otherwise performance of the engine seems great. The lower unit came off of a 90 hp.

 

[foodfisher]

Re: No visible cooling water flow at high speed

Install a telltale and worry nomore.

 

[Jiggz]

Re: No visible cooling water flow at high speed

As recommended install a telltale or in my case I installed water pressure gage on the dash. Normally there will be more indication of water flow at high speed vice lower speed.

 

[pnwboat]

Re: No visible cooling water flow at high speed

What you are seeing is normal for the Force motors. Those two holes are exhaust back pressure relief ports. At low speed when the exhaust snout is deeper in the water, these ports allow exhaust (along with some cooling water) to exit the motor without affecting the low speed performance of the motor. At higher speeds the exhaust back pressure is reduced because the exhaust snout is usually closer to the surface of the water, and also due to the vortex or vacuum (not sure what to call it) affect caused by the forward movement of the leg through the water.

 

[pelletman]

Re: No visible cooling water flow at high speed

What you are seeing is normal for the Force motors. Those two holes are exhaust back pressure relief ports. At low speed when the exhaust snout is deeper in the water, these ports allow exhaust (along with some cooling water) to exit the motor without affecting the low speed performance of the motor. At higher speeds the exhaust back pressure is reduced because the exhaust snout is usually closer to the surface of the water, and also due to the vortex or vacuum (not sure what to call it) affect caused by the forward movement of the leg through the water.

Thats what I was hoping. However, does cooling water exit somewhere else ?

 

[pnwboat]

Re: No visible cooling water flow at high speed

It goes out with the exhaust either via the exhaust snout or back pressure relief ports. There is no way to really see the cooling water dumped out of the motor unless you install a "tell tail" like mentioned above.

 

[pelletman]

Re: No visible cooling water flow at high speed

Thank you. I've been trying to install a telltale, but I'm having a hard time removing the tap screw on the head.
I had put one on a 125 about three years ago that saved me alot of grief.

 

[pnwboat]

Re: No visible cooling water flow at high speed

Might try one of these. You use a hammer to operate it. It really gives whatever fastener you trying to loosen up or tighten a really good jolt. I've seen some that were pretty low cost, or you can also borrow one from some of the Auto parts stores for a small refundable security deposit.

http://www.sears.com/craftsman-impact-driver/p-00947641000P?prdNo=1&blockNo=1&blockType=G1

 

[wlg]

Re: No visible cooling water flow at high speed

I was having a hard time getting that screw out mself. I finally got it out after running the engine in a tub of water and warming it up for a few minutes. I decided to put the screwdriver and adjustable wrench to it and it came out fairly easy. My screwdriver had the area by the handle that you could put a wrench on.