1993 7.4L 454 Mercuiser Water Pump Impeller Problems

[flexall1]

Good Morning.... New to board... I have a 1993 Celebrity Status 240 with a 454 7.4l Mercruiser. Just switched fuel pump over to an electric a month ago. Took boat to lake and impeller went out. Installed new impeller, took to lake yesterday and impeller was out again. When I took waterpump housing off impeller paddles were completely shredded. A month ago when I took it off the paddles weren't completely shredded. Any suggestions. My wife thinks that the boat is just afraid of water....Thanks..

 

[Don S]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

Impellers get shredded like that from lack of water. Do you use muffs when running on land? How long do they last before they fail?
Do you have the hoses on the pump the right way?

 

[flexall1]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

I never run it without the muffs. I think I have the hoses on right.

 

[Bondo]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

I never run it without the muffs. I think I have the hoses on right.

Ayuh,... Did ya lube the new impeller with dish soap,..??

My guess is, ya got the hoses, Backwards...

 

[flexall1]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

No, I did not lube it with dish soap.... Is there a way I can tell if the hoses are crossed??? I ran it Memorial Day weekend for 2 days, about 3 hours and it ran fine. Would it have overheated then if the lines were crossed???? Thanks for all the info....

 

[Don S]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

No, impeller lube is not your problem, and neither are the hoses crossed.
Air leaks in the system between the drive and the pump is the problem.

 

[flexall1]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

Any suggestions on how to check or fix this problem???? Would this have any thing to do with bypassing fuel pump and installing an electric one???? Thanks...

 

[Don S]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

Any suggestions on how to check or fix this problem???? Would this have any thing to do with bypassing fuel pump and installing an electric one???? Thanks...

It could, did your fuel pump mount on the raw water pump? If so, did you cover the hole after removing the pump and fill the cavity with gear lube?

 

[flexall1]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

I never removed the fuel pump... I just capped off the outlets....

 

[flexall1]

Re: 1993 7.4L 454 Mercuiser Water Pump Impeller Problems

Any help would be appreciated...