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1979 Mercury 1150 OB Cooling System Problems

S

steelersman224

New member
Hello,

I've been working on my 79 1150 for the past couple months, and I cant seem to get more than a dribble through to my telltail. I have rebuilt the impeller and made sure that everything was lined up when reinstalling my lower unit. When i went to pull my lower unit for the first time the copper pickup tube came out with the lower unit, and there was a bit of sand around the impeller housing and in the exhaust pipe, but not inside the impeller housing. Looking up into where the pickup tube sits on the top side I can see a little bit of dirt, but nothing blocking the passage. The copper tube is sound other than being a little bit out of round on one end. To the best of my knowledge it seems that I'm just filling up the midsection of the motor full of water. I'm going to replace the pickup tube tomorrow and see if that fixes anything. I've looked in my manual and online for flushing procedures, but haven't found anything. If anyone has thoughts on things I should look into or try it would be greatly appreciated!
 
Could be your engine at one time overheated bad. Melting or distorting the water tube upper grommet. Your cooking system needs to be sealed to work properly. Now your cooling poppet valve or release valve could be open at idle, causing the water pressure to drop
 
Copper tube must be installed into the exhaust housing.-----Then the lower unit is installed.----I do not believe there is a poppet valve on that motor.
 
racerone said:
Copper tube must be installed into the exhaust housing.-----Then the lower unit is installed.----I do not believe there is a poppet valve on that motor.
Click to expand...
is there a seal or some sort of glue that needs to be used? every time i've put the lower unit together I've put the copper tube in the top first
 
UPDATE:

I replaced the copper pickup tube got it seated into the top grommet good. there was a homemade spacer that the previous owner of the motor had put to space the lower unit down further and I deleted that when I pulled the unit. I got everything buttoned back up and ran it with the flush ears and pulled the plastic flush plug on the lower unit and ran the motor. I had great pressure coming out of the flush hole, but after replacing the plug I still am only getting a dribble out of the tell tail. The vents at the back of the unit above the prop have heavy flow and random places on the swivel bracket have water dribbling out of it. I'm not sure what my next step is
 
racerone said:
Copper tube must be installed into the exhaust housing.-----Then the lower unit is installed.----I do not believe there is a poppet valve on that motor.
Click to expand...
UPDATE:

I replaced the copper pickup tube got it seated into the top grommet good. there was a homemade spacer that the previous owner of the motor had put to space the lower unit down further and I deleted that when I pulled the unit. I got everything buttoned back up and ran it with the flush ears and pulled the plastic flush plug on the lower unit and ran the motor. I had great pressure coming out of the flush hole, but after replacing the plug I still am only getting a dribble out of the tell tail. The vents at the back of the unit above the prop have heavy flow and random places on the swivel bracket have water dribbling out of it. I'm not sure what my next step is
 
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