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View Full Version : Changing Impeller in BIII Drive



Wizard29
08-03-2006, 07:16 PM
Where is the impeller located, how do I get to it, what tools do I need and what parts should I go buy?
My water temperature on a Procharged 496HO still reads right where it should, but I'm going to change the impeller as a preventative measure. It's been about two years...

Sotally Tober
08-03-2006, 07:23 PM
Should be on the starboard side bottom pully. Have not changed my HO yet, but pull the seawater pump drain plugs when I winterize.
How do you like your procharger. Is the B3 holding up OK. What speeds are you getting with that outdrive?

Wizard29
08-03-2006, 07:42 PM
Is the raw water impeller located on the engine or in the drive? I've never changed it before. What are the steps to change it?
So far the Procharger is great. No problems with anything whatsoever. The BIII is holding up perfectly. I've heard from some that it is one of the strongest drives available due to beefier internals to handle the dual shafts, but some say there is no difference on the top side. Either way, I'm easy on it and don't jam the throttle down to get on plane. The engine doesn't seem to have any complaints about the Procharger either. I considered upgrading to the 5 PSI boost kit that is available, but I was told by many people not to do it because it screws with the fuel system and will eventually grenade the engine.
With the BIII which cuts down on top speed a bit, I can get 80-85 out of the boat on a good day with minimal fuel, minimal load, and no passengers.

Tom Brown
08-03-2006, 07:45 PM
I thought the raw water impeller was on top of the lower unit housing, like all the outdrives.... just as you said. I'm not a B3 man, though.
You might want to move your Q down to the Outdrives section. Those guys are as queer as happy inmates but they know their service procedures.

Outnumbered
08-03-2006, 07:55 PM
I thought the raw water impeller was on top of the lower unit housing, like all the outdrives.... just as you said. I'm not a B3 man, though.
You might want to move your Q down to the Outdrives section. Those guys are as queer as happy inmates but they know their service procedures.
The late OMC Cobra/K.C. drives had the impeller in the drive itself. They are very easy to change and I always thought that it was a great idea. I could swap out an impeller in 10 minutes. The bravo impeller is located on the lower front of the motor as was stated already. They are a bitch to change if the motor compartment is tight.

Tom Brown
08-03-2006, 08:09 PM
Are the impellers still made of rubber?

Outnumbered
08-03-2006, 08:13 PM
yes.
Here is the typical bravo raw water pump....
http://i19.ebayimg.com/02/i/06/14/d1/ba_1.JPG

Wizard29
08-03-2006, 09:09 PM
Yeah, I have one of those on there. Looks like fun to get in to.
This is what contains the rubber impeller everybody says should be replaced every year, correct? It also contains the brass surface they say could be damaged if debris gets in there? I was never very clear on if they were talking about this type of impeller or the one that is located on some drives.
What parts besides the impeller do I need for this job? Looks like maybe a gasket or o-ring may be required if I have to open that little casing up. What steps need to be taken after getting the drive belt off of that thing?
Tom - "Queer as happy inmates"? Having worked the LA County jails when I was a Deputy, I had to laugh at that one. :) You are one pretty hilarious guy...

Beer-30
08-03-2006, 09:15 PM
Dude, I am not bagging on you, but if you didn't know where the pump was, I would strongly re-consider trying a rebuild.

Tom Brown
08-03-2006, 09:17 PM
Dude, I am not bagging on you, but if you didn't know where the pump was, I would strongly re-consider trying a rebuild.
What does knowing where the pump is have to do with mechanical skill?
You don't have to be Kreskin to change a water pump.

Wizard29
08-03-2006, 09:43 PM
Dude, I am not bagging on you, but if you didn't know where the pump was, I would strongly re-consider trying a rebuild.
Before I was promoted to Production Supervisor for the company I work for, I was an electrical/mechanical engineer for the company. I can figure it out. ;)
I just need to familiarize myself with everything in there before I go taking things apart. And my boat is at our place in Cottonwood while my house is in Oak Hills. I can't exactly go outside and look at it...

Outnumbered
08-03-2006, 10:19 PM
Yes, the rubber impeller is in that housing. I think the 496 has a metal housing though. I never did my own on my 2004 496 so I'm not sure. I changed a buddy's 1997 454 Mag and we bought the entire pump kit (plastic housing and rubber impeller with gaskets) for something like a $100 at the Temple Bar marina shop. I think the 496 housing is way more spendy. Absolute did my impeller on my 496 with 50 hours and the housing was scored from sand. He can resurface the housing/plate and save you a ton O' cash. Just pull the fawker out and if it looks scored take it in and have it resurfaced.

KLEPTOW
08-04-2006, 02:46 AM
Dude, I am not bagging on you, but if you didn't know where the pump was, I would strongly re-consider trying a rebuild.
So what do you need a PHD now to change a impeller?
and yes you were bagging on him.
I could see it if he came on here and said he pulled his motor and cant find the impeller, dam give people a break.

Dribble
08-04-2006, 06:15 AM
Yeah, I have one of those on there. Looks like fun to get in to.
This is what contains the rubber impeller everybody says should be replaced every year, correct?
Tom - "Queer as happy inmates"? Having worked the LA County jails when I was a Deputy, I had to laugh at that one. :) You are one pretty hilarious guy...
That's the one, but I only change mine about every three years and I'm anal as hell. Just avoid the dry starts and don't store the boat outside in freezing weather and three years or about 100 hours is fine. I have to pull the back seat to get to mine.

Beer-30
08-04-2006, 06:25 AM
So what do you need a PHD now to change a impeller?
and yes you were bagging on him.
I could see it if he came on here and said he pulled his motor and cant find the impeller, dam give people a break.
No, you don't.
And, no, I wasn't.
My thought was similar to, say a person couldn't find the prop on an outdrive, but wanted to change it. It seemed as maybe he was just getting into do-it-yourself type stuff and I was suggesting a different avenue until he was familiar. That's all I meant.

PHX ATC
08-04-2006, 06:29 AM
I did the old impeller swaparoo on my 2003 Nordic with a 496HO. I had a buddy (BigDogIvan) help me out...he watched while I cussed. :)
Looking at the front of the motor, it's on the bottom left side. Loosen the belt tensioner which then allows you to flop the belt off. Then crawl down there, bend your arms at 2000 degrees of bendiness and start undoing bolts, 1/16 of a turn at a time. In all reality, there's only 3 bolts that hold the housing to the motor, but I undid 6 bolts for some reason. Take the housing off, put it on the bench or garage floor, open it up, and wallah! Impeller! Take note of which way the flippers bend, as you want to install the impeller flippers bending the same way or it won't work. Take digital pictures if you're stupid like me! Then, put it back on the engine and pray.
It's really easy!

phebus
08-04-2006, 06:41 AM
I did the old impeller swaparoo on my 2003 Nordic with a 496HO. I had a buddy (BigDogIvan) help me out...he watched while I cussed. :)
Looking at the front of the motor, it's on the bottom left side. Loosen the belt tensioner which then allows you to flop the belt off. Then crawl down there, bend your arms at 2000 degrees of bendiness and start undoing bolts, 1/16 of a turn at a time. In all reality, there's only 3 bolts that hold the housing to the motor, but I undid 6 bolts for some reason. Take the housing off, put it on the bench or garage floor, open it up, and wallah! Impeller! Take note of which way the flippers bend, as you want to install the impeller flippers bending the same way or it won't work. Take digital pictures if you're stupid like me! Then, put it back on the engine and pray.
It's really easy!
Next time, just pull the bracket that holds the water pump on. Three bolts, and much easier to access then the little bolts that hold the pump to the bracket. Then, just change the impeller on the bench.
Changing the impeller is very easy, accessing it is the problem on some boats.

PHX ATC
08-04-2006, 06:54 AM
Next time, just pull the bracket that holds the water pump on. Three bolts, and much easier to access then the little bolts that hold the pump to the bracket. Then, just change the impeller on the bench.
Changing the impeller is very easy, accessing it is the problem on some boats.
While I was bent like a pretzel in the engine compartment (incredibly small in the Nordic), I realized that the 6 bolts were 3 too many when I got it off! But, working blind, I was just happy I got the thing off! :)
Your advice is the way to go, much easier that way.
My 6.2L engine in my "new" Sea Ray has the same setup, so I will be wiser on this next impeller swap. Plus, the Sea Ray has a dance floor in the engine compartment, so I can have a martini while changing it out!

KLEPTOW
08-04-2006, 06:58 AM
Where is the impeller located, how do I get to it, what tools do I need and what parts should I go buy?
My water temperature on a Procharged 496HO still reads right where it should, but I'm going to change the impeller as a preventative measure. It's been about two years...
One more very important item, If the impeller is not in one piece dont stop looking until you find it all, it maybe a pain in the ass but a hell of a lot cheaper than buying a new motor.

Boozer
08-04-2006, 08:55 AM
Is the impeller going to be in the same location in an Alpha 1 application as well? I need to change mine today.

Sotally Tober
08-04-2006, 10:09 AM
I believe the impeller is actually in the outdrive in an alpha. Going to have to pull the drive.

scarabrick2
08-04-2006, 10:11 AM
Alpha water pumps are located in the lower unit. drain the oil and take off the 7 bolts. six on the side and one under the trim/anode fin. pump is on the top. make sure you pressure check the oil cavity so you don't have any leaks. I think you can go on line and print out the actual direction. Don't know the site but google it.