7.4 Merc bravo one water impeller location getting hot...

[DOUBLER]

Newbie here been looking through the forum for information on this.So this is the situation i have a 89-90 chaparral 2350 sx with a 7.4 mercrusier so last week i went to turn it on i put on the mickey mouse ears turned on the water and proceded to turn the key it turned on was running and notice there was no water coming out the exhaust so no biggey truned it off and got a plastic barrell filled it with water and turned it on again seen the temps rizing and still no water was coming out the exhaust .

So i went and bought a new thermostat and changed it turned on still nothing and temps were rizing.So after reading this forum i read that it might be the water impeller? Were do i locate it on the 7.4 merc?And what whould be the part,kit number for the impeller for this motor?

Might this be the problem?Engine turns on fine revs fines but than reaches hot temps than i shut it down before it starts buzzing that it is hot.

Here are some pictures..Thanks for any help or any input on this ..Hoping to get this ready in 2 weeks so all help is apprciated..

Thanks for your guys time...Robert..

 

[sker crunch]

Re: 7.4 Merc bravo one water impeller location getting hot...

n/m

 

[Reel Poor]

Re: 7.4 Merc bravo one water impeller location getting hot...

The impeller IS NOT in the drive. It's located on the lower right side of the engine. The raw water pump is driven by the a fan belt.

 

[HT32BSX115]

Re: 7.4 Merc bravo one water impeller location getting hot...

After you replace the raw water pump. you'll need to locate all the pieces of the pump that are all crammed up in the oil cooler too. those pieces of impeller will be stopped by the oil cooler if it's installed on the discharge side of the pump.
You also may have to replace the housing too.

 

[TilliamWe]

Re: 7.4 Merc bravo one water impeller location getting hot...

As far as where to buy the repair kit, I would check out boatfix.com
Your may be the "old" three piece style, and you'll want to upgrade to the "new" style. At boatfix.com that kit was $44.08 last month and its number is SIE 183150 (It's a Sierra kit).

 

[DOUBLER]

Re: 7.4 Merc bravo one water impeller location getting hot...

Thanks for the info reel poor than you so much for pointing it out for me on the picture,HT32BSX115 thanks for the tip ill check for all the pieces and check the oil cooler,TilliamWe thanks for the part number and the info on updating the part..

Thanks to all once again ...Robert

 

[DOUBLER]

Re: 7.4 Merc bravo one water impeller location getting hot...

Hey fellas bumping this up from 5 years back My impeller i replaced 5 years ago finally decided to throw in the towel tonight it was a good run and gave me some amazing time and memories with family & friends So i was looking for the replacement part that i purchased 5 years back ( SIE 183150 kit ) that TilliamWe posted , went to boatfix.com and the kit dosent show up also looked around for it and no part shows up is there a upgrade for this kit ? or a new part number for the 7.4 Merc bravo one ^ same picture i posted 5 years back

Im currently in the works of selling this boat but want to make sure everything is in great running condition so the new owner has no problems with it when taking it out to relax the day away
Thanks Fellas

Robert

 

[DOUBLER]

Re: 7.4 Merc bravo one water impeller location getting hot...

double post srry

 

[Bondo]

Re: 7.4 Merc bravo one water impeller location getting hot...

Ayuh,.... 18-3150 comes up as the Alpha, Gen.II water pump,...

There's a Bravo pump at the bottom of this page though...

 

[DOUBLER]

Re: 7.4 Merc bravo one water impeller location getting hot...

Thanks Bond-o I guess by not adding the( - )in between the part number was not giving me the part :facepalm:

? is there a sensor on the stern ( the hockey puck ) that if it goes bad keeps the trim from working ? i bypassed wires everything works fine but when connected keeps it from going up or down.sorry for the question and not creating another thread or searching just thought i would ask here first ..

Thanks

 

[Don S]

Re: 7.4 Merc bravo one water impeller location getting hot...

The reason you can't start a new thread is because you are listed as an abandoned user for not posting in a while. I will get the IT guys to fix it for you.

 

[Bondo]

Re: 7.4 Merc bravo one water impeller location getting hot...

Thanks Bond-o I guess by not adding the( - )in between the part number was not giving me the part :facepalm:

? is there a sensor on the stern ( the hockey puck ) that if it goes bad keeps the trim from working ? i bypassed wires everything works fine but when connected keeps it from going up or down.sorry for the question and not creating another thread or searching just thought i would ask here first ..

Thanks

Ayuh,... 1 of those is the Trim Limit switch, which is givin' ya trouble, 'n the other is the trim gauge sender...

I disconnect 'em at the get go, 'n run by seat of the pants, bein' careful to not over-trim, manually...
I like 1 button trim, through tilt...

 

[DOUBLER]

Re: 7.4 Merc bravo one water impeller location getting hot...

Thank you DON S yeah been a long minute since i been on here i just really read most of the threads and get info when having problems,Thought would ask before doing things 3 times before finding out the gremilins that struck saterday night.

Bondo-o Thanks i followed all the the wires to the selenoid ( which are working) and notice the lone purple wire running to the stern so i disconnected it and had trim switch working again , By having it disconected the trim gauge wont work right?

Thanks once again

 

[DOUBLER]

Re: 7.4 Merc bravo one water impeller location getting hot...

Do they sell the rubber impeller it self or only as a kit?



Thanks

 

[Don S]

Re: 7.4 Merc bravo one water impeller location getting hot...

You should be able to start new threads now.

As far as your impeller, yes you can buy just the impeller. BUT!!! Depending on your pump, you need the gaskets and/or seal rings to seal the body to prevent air leaks.

 

[DOUBLER]

Re: 7.4 Merc bravo one water impeller location getting hot...

Thank you Don


I ended up buying the kit glad i did, i did some more reading to figure out what is going on opened up the thermostat and it filled with water when it heated up the thermostat did its job and opened. Heared the buzzard of death so i shut her down , I started to remove the hoses and water poured out from there good sign i guess but no water out the muff, as i removed the water impeller housing i opened it up water came out and the impeller was in one piece did find the back of the house to be a bit damaged

and the impeller

Before the water stopped coming out the muffler and temps started rising, i started hearing a "thud thud thud thud thud thud" coming from the engine compartment than it went away and temps went up.

Were might there be something clogged?if it wasn't due to the impeller going out? im taking everything apart and giving it a good cleaning also inspecting what i find along the way and replacing what needs to be replaced all that has been replaced has been the impeller and trim sensor's since "91" when my father owned it.


Thanks

 

[Don S]

Re: 7.4 Merc bravo one water impeller location getting hot...

Yeah, you need a new pump housing as well, that one is junk. Use some dish liquid on the impeller to make it easier to install.

i started hearing a "thud thud thud thud thud thud" coming from the engine compartment than it went away and temps went up.

I think if you find what the noise was you will find the problem.

You could have an air leak in the inlet side, that would prevent water getting to the pump,