496 Mags, impellers, I did a search allready odd question.
 

So replacing both, and have a question.

I have 2004 model 496 mags. According to Mercruiser,

http://www.mercruiserparts.com/images/COMMON/4810.png

http://www.mercruiserparts.com/Show_...=SEAWATER+PUMP

I need 47-862232A2 part number. and when I try and order that part the O-ring / gasket is round in all the pics seen here.

http://www.marine-power.co.uk/image/...A2-500x500.JPG

But the pump housing, is odd shaped and the O-ring goes all around.

Like this
http://i.ebayimg.com/t/MERCRUISER-IM...sjZw~~60_3.JPG

SO does the round O-ring just bend around and form to the odd shape, or am I looking at the wrong part number. Cause in the Merc diagram above (part 3) it shows the O-ring shaped like the housing but the part number they send me to has the round one.


????? thoughts?

It just conforms to the shape needed, post a pic of your end plate. Many times there is too much wear or groves worn in it that will make the pump basically inoperable. Your old impeller conformed to the groves because it made them, the new impeller will not.

This is not my pump, just Google images.

Just wanted to double check before ordering the part kit, X 2 for the job. want to have all the parts ready to go on hand. I hope the plat is not to worn, as the motors only have 220 hours total. but who knows.. IF they are past gone I will replace with stainless. But hopefully just new rubber and seal and put back together.

The O-ring is round. The housing is double pear shaped.

Use a little bit of Vaseline, or clear flexible silicone to keep the O-ring stuck in the grove when re-assembling the pump. It's MUCH easier to do this with the entire pump/pulley/housing in your hand, vs. half of it installed on the engine. (Can be done both ways, but the former is way better.)



Wrap a zip-tie around the impeller and cinch it down to lean all the veins over in the correct direction before insertion. Once you have the impeller half way inserted; cut the zip-tie with dykes and pound it in with a rubber mallet.
Use dish soap to lube your impeller when inserting.

Yes I have changed impellars many times just not with these pumps. (Older plastic housings) But will be lubeing with dawn dish soap. And taking the whole pump off.

Just wanted to make sure the O-ring was round and not pre shaped.

If you have 220hrs I would definitely be checking the housings. Mine were worn after 120hrs & didn't want to prime. When I took the pumps off 1 fell apart in my hand ( meaning the shaft, front bearing, & seal fell out of the housing) the other shaft was ok but both housings had large gouges in the front and on the rear plates. JMO Randy

Well that's not what I wanted to here ha.

That is crazy low on hours for them to be wore so bad. I have seen black toros last 1400 hours. Sure hope mine don't have that problem...

There is a company that makes rebuild kits with stainless wear plates for each end but I can't think of their name, Hardin Marine makes a nice stainless replacement pump for just over 1/2 price of a new merc unit. Hope that helps you out. Randy

The name of the company that sells the wear plates is JC marine. 928-505-5252 I put these in my pumps which had Badley scored plates and they have been working fine coming up 4 years.

I think this is the kit you are referring.. Thanks for the heads up Paul.

http://www.jcmarinellc.com/water_pump_kit.htm

I will keep this link handy, and if they are worn, order 2 of these with a quickness.

Also which side of the pump get the groves that mess everything up? Both? and does anyone have pics of how bad they is to bad?

I think I still have the worn factory pump in my garage. Pm me your email and I'll send you some pictures of it.

Dude, just order them and put them in. They are stainless, so they are harder than your existing casting. You will get another 200 hours and wont have any issues. Just follow their instructions - easy. They are a good refurb upgrade.

Zyou beat me to it , it's a good idea to just put them in even if the scoring isn't too bad,they will protect your pumps from further scoring and you new impellers will be running on nice new flat surfaces.

I could do that too.

But seams like why do that if the housings are not worn to bad yet?

A lot depends on the water conditions you boat in... If you beach the boat or are in shallow water a lot, then more sand will enter the system, thus wearing your housing faster. I have just over 400 hours on the Velocity I just sold (496 mag) and the last time I changed impellers the housing looked great.

99 % of my boating is in fresh water Tennessee river. And am carefully abotu where I fire up I am not in the mud or sand.

The boat makes one trip a year to the Destin area and then Its flushed not just on the hose but back in the river and ran. My parents 496s in there formula have either 400-600 hours on them and the housings are fine....

After this go around, they will be scored more.

Think of it as preventative maintenance. For $200 you can use those raw water pumps for the life of your boat. I also think that since the surface is harder, they increase the life of the impeller since they dont pit it, gouge and rub away at it.

Maybe I am missing something?

This KIT will also fix a grooved pump? Correct? so there is no harm is just doing impellers UNTIL they need the kit?

Or is there a point in doing the kit BEFORE the groves are bad.

even if the housing is worn the new impellers will work but not on the hose at first, you have to run them the first time with the boat in the water so the pumps are getting water by gravity alone or close to it, after you run for a few hours the new rubber will wear it self into the grooves in the wear plate and work fine. It will also help to prime them with water from a hose above the pump before starting them. Or you could just put the stainless rebuild kits and be done with it.

I replaced mine with hardin marine stainless pump. awesome. fits right in using back plate of stock pump and can be rebuilt for 68 dollars. no brainer :lolhit:

I Appreciate the posts. but can someone answer my question.

IF my housings are not bad yet, WHY do the fix YET. why not put 30 buck worth of rubber in, and go again. now once they are messed up, I can do the kits so i dont have to buy new pumps. I agree at that point go with the kits But there is no point to replace them until you I have the problem.

Unless I am missing something the kits, cover where the pump housings get worn, so no harm in waiting until they are worn to do the fix.



And I NEVER start new impellers on the hose. once they are replaced it goes in the water. I try not to use a hose at all other then when i HAVE to.

Here's a pic of mine 2 years ago when my mechanic went to change the impellers. He put a new impeller in and he couldn't get it to pump water no matter what he tried. He dropped the boat in the lake and tried to get the water to pump. He ended up replacing the whole pump. He didn't know about the wear plate kit that was available.
http://i56.photobucket.com/albums/g1...1EAFCB6C04.jpg
http://i56.photobucket.com/albums/g1...8F6B9F5A28.jpg
http://i56.photobucket.com/albums/g1...249B95CF02.jpg

I agree, put the impellers in, put the boat in the water, if they pump you are done, they will only pump better as time goes on and they wear into the existing grooves.

older plastic housings had a wear plate with an o-ring behind them new style pumps are all brass and to be reused if you are getting bad wear marks in the housing itself then you probably want to just go ahead and replace the whole pump the bearing are probably shot idk why these pumps have such a problem with the bearings but the shaft will actually pull out in your hand if it gets bad enough i work for sea ray and we have replaced tons of them 4.3's 350 mags 496 there all the same i wish they would go back to the plastic housing i thought they were much better

when reinstalling new impeller install with mercury marine grease if you get a whole new pump they are not pre-lubed spray some some kind of lube in the pump and work the impeller shaft around until it gets real easy to turn

The new replacement pumps from Merc have stainless wear plates. Guess they figured out the all brass wasn't the best idea.

I like to use Dawn Dish soap, as it lubes it well, and washes out with out any harm