lower unit issues

hookups08

Seaman Apprentice
Joined
May 31, 2010
Messages
30
So I last posted about my prop not giving me good speeds, I was told to check the hub, remarked it and still it is not working. It seems when I give decent throttle that it wont speed the prop up and my RPM's increase as though I were in neutral. I see a lot of air bubbles coming from the rear above the prop and some air bubbles are coming from the vents where the water goes into the water pump. I can troll along just fine but when I increase throttle I do not increase speed. Its a 1960 Johnson 40 HP and any assistance would be greatly appreciated!
 

wilde1j

Vice Admiral
Joined
Apr 15, 2002
Messages
5,964
Re: lower unit issues

I think you were asked to try and post pictures of the boat (out of the water), so we can see where the lower unit is relative to the hull bottom. You haven't otherwise provided enough info for us to help you guess.

If the boat has a 20" transom and the motor is a 15" piece, it would perform as you describe. BTW, has this boat/motor combination ever performed properly???
 

hookups08

Seaman Apprentice
Joined
May 31, 2010
Messages
30
Re: lower unit issues

Oh ya, I will try and get it out of the water tomorrow and post some pictures...if I cannot, is there anyway I can measure?
 

hookups08

Seaman Apprentice
Joined
May 31, 2010
Messages
30
Re: lower unit issues

I found a website that shows the correct shaft length per the length of the transom...I will check it tomorrow and get back with you...thanks!
 

hookups08

Seaman Apprentice
Joined
May 31, 2010
Messages
30
Re: lower unit issues

Ok I have a 22.5 inch transom with a 25 inch shaft.
 

Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
28,124
Re: lower unit issues

OK, Did you use a sharpie to draw a line from the aluminum prop to the brass hub? That will tell us if the prop is slipping. You do have a good drive pin in the prop?
 
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