Mercruiser 165 water pump

mike2011 · Oct 14, 2011

I have a Mercruiser 165. I have a leak coming from a factory hole behind the impeller. The screw that attaches the impeller is stripped. I am having trouble getting it off to replace the seals. Anybody have any ideas of how to get the impeller off with the stripped screw?

Bt Doctur · Oct 14, 2011

Re: Mercruiser 165 water pump

Merc 165 WHAT? 3.7L circulating impeller, or impeller in the drive

Don S · Oct 14, 2011

Re: Mercruiser 165 water pump

I have a Mercruiser 165.

That narrows it down to 2 engines, is yours the 4 or 6 cyl version of the 165?

I have a leak coming from a factory hole behind the impeller.

Which impeller are we talking about? The one on the engine or the one in the drive?

mike2011 · Oct 14, 2011

Re: Mercruiser 165 water pump

Don S said:
That narrows it down to 2 engines, is yours the 4 or 6 cyl version of the 165?

Which impeller are we talking about? The one on the engine or the one in the drive?

It is a 4 cyl. It is the impeller that is in the engine not the foot.

stonyloam · Oct 14, 2011

Re: Mercruiser 165 water pump

mike2011 said:
I have a Mercruiser 165. I have a leak coming from a factory hole behind the impeller. The screw that attaches the impeller is stripped. I am having trouble getting it off to replace the seals. Anybody have any ideas of how to get the impeller off with the stripped screw?

If you have the stud attachment, most likely you are turning it the wrong way. I believe you have to turn the impeller clockwise to remove it.
Found this: "More recent models had a "nut-shape" cast into the impellar and the entire impellar threaded onto the end of the camshaft (spins to right to remove)".

achris · Oct 14, 2011

Re: Mercruiser 165 water pump

mike2011 said:
It is a 4 cyl. It is the impeller that is in the engine not the foot.

Oh, it has an impeller in the drive ('foot') too... Just to make life that bit more interesting...

mike2011 · Oct 15, 2011

Re: Mercruiser 165 water pump

stonyloam said:
If you have the stud attachment, most likely you are turning it the wrong way. I believe you have to turn the impeller clockwise to remove it.
Found this: "More recent models had a "nut-shape" cast into the impellar and the entire impellar threaded onto the end of the camshaft (spins to right to remove)".

The problem is that the screw in the middle of it is stripped so i have no way of being able to hold that screw in place to remove the impeller or to take the screw out and then get the impeller off. Is there good way that i should go about getting it off or will i end up having to just cut the nut off and the screw in order to get the impeller off

stonyloam · Oct 15, 2011

Re: Mercruiser 165 water pump

mike2011 said:
The problem is that the screw in the middle of it is stripped so i have no way of being able to hold that screw in place to remove the impeller or to take the screw out and then get the impeller off. Is there good way that i should go about getting it off or will i end up having to just cut the nut off and the screw in order to get the impeller off

If you have the impeller with the "nut shape", I believe you can hold the stud it with a Allen wrench inserted in the end. I am not sure what is stripped. Does the impeller spin on the stud, or does the stud turn in the cam? If the impeller turns on the stud, you may be able to unscrew the stud using an allen wrench. May need some heat as it could have been installed with locktite. Not exactly sure which way the stud turns to come out, you can check with your local Mercruiser dealer, sounds like you will need a new impeller anyway.

mike2011 · Oct 15, 2011

Re: Mercruiser 165 water pump

stonyloam said:
If you have the impeller with the "nut shape", I believe you can hold the stud it with a Allen wrench inserted in the end. I am not sure what is stripped. Does the impeller spin on the stud, or does the stud turn in the cam? If the impeller turns on the stud, you may be able to unscrew the stud using an allen wrench. May need some heat as it could have been installed with locktite. Not exactly sure which way the stud turns to come out, you can check with your local Mercruiser dealer, sounds like you will need a new impeller anyway.

Yes it is the allen wrench screw that is stripped out. We tried to put heat on it and that still is not working.

stonyloam · Oct 15, 2011

Re: Mercruiser 165 water pump

mike2011 said:
Yes it is the allen wrench screw that is stripped out. We tried to put heat on it and that still is not working.

Sorry I am so thick LOL. So when you turn the impeller (with a wrench on the molded "nut" ) to the right (clockwise) the stud turns too?

mike2011 · Oct 16, 2011

Re: Mercruiser 165 water pump

yes

stonyloam · Oct 16, 2011

Re: Mercruiser 165 water pump

That is not good! You could try inserting an Allen wrench into the stud and holding it firmly in place and then turn the impeller to the right to see if you can remove the impeller from the stud. Someone may have used locktite on the impeller threads, so heat may help. If that does not work, you could try some vicegrips on the impeller, pulling outward as you turn it to the left. I am not absolutely sure but I think the stud unscrews from the cam by turning it to the left. Sounds like the stud threads stripped out in the end of the cam when you tried to remove the impeller. good luck.

Mercruiser 165 water pump

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