56' 7.5hp not spitting water from exhaust port - please help!

D

Duke696

Recruit
Joined
Sep 4, 2011
Messages
2
The kids and I want to take the old man's 7.5 Johnson fishing. I put the motor in a trash can full of water, and started. The engine started right up as always, but the water did not spit out of the hole where I usually see it in the rear of the main shaft. Instead it is dripping out of the back bottom engine housing. I remember when out with the old man, sometimes it took a little bit and the spitting began. But I have run it for a bit and it still comes out from under the engine in the back. Is there a plug or something that should be replaced or???? I would ask the old man but he is gone - last October. He used this motor for trolling on his 19' Century.

Any help would be appreciated.

Duke
 
kfa4303

kfa4303

Banned
Joined
Sep 17, 2010
Messages
6,094
Re: 56' 7.5hp not spitting water from exhaust port - please help!

Hi Duke. Welcome to iboats. You probably just need a new impeller (water pump), especially if it hasn't been changed in a while. You may have ablickage of some sort as well. You can check when you drop the lower unit to change the impeller. Hook a garden hose up to the copper, water uptae tube in the lower end. turn on the water and see if you can see it exiting out of the exhast port. If so, then you passage ways are clear. If not, then you have a blockage some where. It's not that uncommon. Some times old water pumps degrade and get sucked up into the power head. If you do find a blockage, try to determine if it's in the uptake tube and/or the power head. You can check the power head for blockages by removing the head and/or exhaust plate. The good news is that you can get the impeller right here at iboats, and assuming you don't have a blockage some where, it's a pretty quick and easy job. Here are some hand links for your motor and old OMC in general. You have to remove the powerhead to get to drop the LU. Here's a vid on how to do it. Try some of these tricks and report back. Good luck.


http://www.youtube.com/watch?v=SVOedhzPP7M&feature=results_main&playnext=1&list=PL8F66708F3A4C33AB
http://forums.iboats.com/showthread.php?t=158086
http://www.duckworksmagazine.com/07/columns/max/index1.htm
 
metriccrescentwrench

metriccrescentwrench

Commander
Joined
Oct 22, 2007
Messages
2,598
Re: 56' 7.5hp not spitting water from exhaust port - please help!

Kinda' sounds like it's past time to replace the water pump imeller. I'm by no means an expert on this particular engine, but periodically servicing the water pump is universal among outboards.

BTW, post some photos of your engine. When I was a kid I spent hour upon hour running around in a small aluminum boat pushed by a '56 Johnson 7.5, and I've got in the back of my head that I'd like to find one to restore someday.
 
B

Britcheflee

Petty Officer 3rd Class
Joined
Oct 4, 2010
Messages
79
Re: 56' 7.5hp not spitting water from exhaust port - please help!

That is what I am working on at the moment - same problem - the removal of the power head is no big deal and actually for me getting the lower unit off was easier than with the newer 6hp fisherman and trying to get that stupid screw into the clamp whilst pushing it up and holding it in place and moving the gearshif and not trying to drop the screw....you get the picture.
I have found that with both the 6hp and the 7.5 hp getting the screws out that hold the top of the impeller housing is a bear - I had most luck with an impact screwdriver and some heat - dont fret if the top of the screw snaps off - on one of them - if you are very careful you can still get the top off as the first part of the housing where the screw goes in is not threaded - once the top is off you can get some grippers on the stub and get it out.
I ordered my parts via a different source as they were having a sale - also might as well get the upper gasket on the drive shaft where it sits on the power head and a new grommet for the copper pipe....see other thread for question about that.
I cleaned out the impeller housing and lightly sanded the base on wet and dry to get good seal - after doing that on the 6hp water came out just fine!!! Hopefully you will have same luck with yours!!!!


Lee
 
D

Duke696

Recruit
Joined
Sep 4, 2011
Messages
2
Re: 56' 7.5hp not spitting water from exhaust port - please help!

Thanks for the responses. :) I have dirt bikes to work on, then the Johnson. Should get to it around Wednesday. I will give y'all a report.

Thanks again.

Duke
 
You must log in or register to reply here.
Top