1989 Johnson 120Hp V4 Looper Overheating Problem

[SOAPSTONEARTIST]

well I guess joe wants me to start a new thread as the one I was using was 11 months old. Still pertinent though and plenty of good advice from previous postings. The problem(s) I was having seem to tell me that my water pump impeller "might" be the cause. I also have to check all the ground connections to get the warning horn to work.
The problem was that while I was running at all speeds up to full throttle everything was working fine. Once I get to full throttle it would just bog down and I would have to reduce throttle speed to almost half. IF I stopped and turned it off for five minutes, everything would be fine again except that at full throttle the same thing would happen. At first I thought it might be fuel lines getting old and soft and restricting fuel flow so I replaced them all. I found out on this forum that it could possibly be the pump impeller wearing out ( as it's been 6 years since I last replaced it, along with the VRO pump) and things worked fine for five years until my current problem began. I have ordered a water pump kit and once that gets installed and I can test it I'll post my findings. Thanks for all the help...already!

 

[joereeves]

It's not that I wanted you to start a new thread... it just that it's best for members to have their problem listed under their own title and member name with an original listing rather than to be buried under someone elses hijacked post that could (and usually does) in turn become hijacked time and time again. It was also 17 months old, not 11.

Your engine..... As it stands, are you sure that it was overheating?

The warning horn system being operational is a must. Is that working okay now?

If the engine actually got hot enough to start to seize the engine, that should have melted various wires and discolored the paint in areas. Did it?

If a fuel restriction, the fuel primer bulb would have a tendency to go flat. Did it? Keep us updated.

 

[SOAPSTONEARTIST]

It's not that I wanted you to start a new thread... it just that it's best for members to have their problem listed under their own title and member name with an original listing rather than to be buried under someone elses hijacked post that could (and usually does) in turn become hijacked time and time again. It was also 17 months old, not 11.

Your engine..... As it stands, are you sure that it was overheating?

The warning horn system being operational is a must. Is that working okay now?

If the engine actually got hot enough to start to seize the engine, that should have melted various wires and discolored the paint in areas. Did it?

If a fuel restriction, the fuel primer bulb would have a tendency to go flat. Did it? Keep us updated.

OK Joe Now I understand. Thanks for clearing that up. I was "hijacking" on that post because my problem was very similar to his, but that's all over now and I have my own thread started.
As far as my engine, I'm not positive that it was overheating as it never got too hot to put your hand on any of the cylinders. The "pee stream" seemed to be fine but it never changed volume no matter what speed the engine was running so I think it best to change the impeller and the kit I bought was inexpensive and it also changes all the rubber o-rings and the housing, which I read tends to crack!
I am planning to work on the warning horn test tomorrow as it's a Saturday and our weather has finally warmed up enough to do work outside.
I don't think the engine got that hot ( to melt wires etc) and I don't see any discoloured areas.
The primer bulb never did go flat so I think I changed the fuel line to 3/8" copper line when the original rubber line was still working fine!
Thanks so much for your help and I'll keep you posted when I finally get to use this boat!