Broken impeller housing bolt

R

raywm3

Cadet
Joined
Jun 20, 2009
Messages
11
Hi guys.

I have an old (1969) Johnson 25 hp, 2-stroke. When recently replacing the impeller, one of the three water pump housing bolts broke off inside the lower unit.

I can put the other 2 bolts back in and tighten the housing pretty good, so my question is, how critical is this 3rd bolt? Does that housing need to be sealed tight to the chrome impeller plate beneath it or can I get away with just 2 bolts holding it on? Thanks.
 
lindy46

lindy46

Captain
Joined
Nov 27, 2008
Messages
3,886
Re: Broken impeller housing bolt

Is the bolt end sticking up so you can get a vice-grip on it? If so, soak it good in penetrating oil and try removing it. If not sticking up, you'll have to drill it out and re-tap.
 
T

tmcalavy

Rear Admiral
Joined
Aug 29, 2001
Messages
4,005
Re: Broken impeller housing bolt

If you have to rely on removal and tapping it, take it to a machine shop...get it done right.
 
R

raywm3

Cadet
Joined
Jun 20, 2009
Messages
11
Re: Broken impeller housing bolt

Well, I would definitely have to drill it out, as it is broken off inside. However, my question is, how critical is it to do this? It's an old motor and that housing isn't sealed on to the chrome plate in any way. It appears as if it's just tightened down- no gasket or sealer.
 
Tim Frank

Tim Frank

Vice Admiral
Joined
Jul 29, 2008
Messages
5,333
Re: Broken impeller housing bolt

My intuitive response would be "if it wasn't needed, they would not have put it there."
You can try it with two bolts, but if you find it really did need three, fixing it right the first time will look like it would have been a better choice.
 
Chinewalker

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: Broken impeller housing bolt

Two bolts have a habit of raising the non-bolted side enough where the pump works less efficiently. I did one of these a couple weeks ago - used the pump housing as a guide and drilled the old screw out, then tapped it up one thread diameter in size and was good to go.
 
R

raywm3

Cadet
Joined
Jun 20, 2009
Messages
11
Re: Broken impeller housing bolt

Thanks for all of the advice!!! I'll drill and tap!
 
F

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,195
Re: Broken impeller housing bolt

To add my 2c, the housing has to be down water tight on the intake side. If air gets in, it will mess up the pumping efficiency.

I hope you are experienced in drilling out screws. This is one area that separates the do-it-yourselfers from the pros. The DIYer will mess it up 99% of the time. The people that "think" they are pros will only mess it up 70% of the time. That is a stainless steel screw in an aluminum housing.
 
Cofe

Cofe

Lieutenant Commander
Joined
Apr 23, 2009
Messages
1,883
Re: Broken impeller housing bolt

Spray it down with PB Blaster and use a high grade Left Hand drill bit to drill it out. From my experience, the drill bit sometimes catches on the bolt, and being left hand, the bolt will unscrew itself. 70% of the time.
 
You must log in or register to reply here.
Top