ComfortablyNumb

Beautiful day in Colorado today. All pumped up to get the boat in the water tomorrow. Get everything ready to go. Double check everything and turn on the water and start the engine. Running great, so I hop out hop out and look. No water at all from the exhausts. I turn the motor off, double check everything. Take out the blue plugs, no water. ???? Got my lower water pickup taped off, double check the muffs and hose attachments, water to the outdrive is fine. Blue plugs back in and Start the motor again, run to the back of the boat, still no water from the exhausts. Look in the bilge for any problems and find none. Water pump starts sqealing. Shut the motor off. Water pump is hot. Now what. It ran fine when I winterised it. Drained everything like I normally do the past 3 winters. Engine has only 24 hours on it.

I suppose it's time for a rebuild. I can pull the pump and bring it to a shop. But I'm not sure what the potential problem is yet. Any ideas? Is there an aftermarket pump available for the 496 yet? The boards here have raised a lot of issues with this pump and as long as I'm going to spend some money I'd like to spend it in the right place. Thanks.

Rippem

trashed the impeller. that was the squeek of dry hot rubber against the housing. 5 minutes to swap impellers, 45 minutes and some profanity to get the pump off and open. I smoked one winterizing, replaced it, have to do the other next week.

They should be changed bi-annually if not every spring.

That pump is kindof a PITA to work on...but nothing you can't do.

Twist the new impeller into the housing with liberal Vasaline and then some. It'll keep it "lubed" until it gets water the first time.

ComfortablyNumb

Thanks Rippem,

I went over to the merc mechanic and they said impeller also. 30 some bucks for the part. I'll get some bandaids for my knuckles tonight and start in on it in the morning. Hopefully the housing isn't scored or something.

MOP

I would bet the squeal was the belt slipping on the pulley, that is common as the impeller being rubber will take a set when left to sit a long time. Many times you can loosen the belt a nd break it loose and be good to go, I would try that before you break your butt getting it apart.

Phil

Rippem

it's the impeller.
the squeel was after it had been running and moved no water. that dry rubber will only go around just so many times before it gets hot, breaks apart, and the hot dry fragments squeel getting dragged around against the housing by what's left intact.

those impeller blades take a curved set in "shape", but don't stick to the housing, and would never stick hard enough to get the belt to slip around the pulley.

doesn't matter, it's time to change them anyway!

ComfortablyNumb

Impeller was toast, housing is fine. Looks like I "flipped" a couple of blades. Merc mechanic says that can happen when its dry and you first crank the engine. I can see where pieces from an impeller can cause major head aches. Took about an hour to get if off and apart. The diagrams posted elsewhere aren't exact. Think I could do it in half an hour next time now that I know what need to happen.

Thanks for the advise

MOP

Makes one want to consider a crank mounted pump, no belt to steal HP and the impeller change takes about 10 minutes.

Phil

Sydwayz

I added a t-fitting into the raw water intake to the SWP on my 496HOs. No more dry starting.

ComfortablyNumb

Good Idea. I think I'll do the t fitting also. My boat sits from October- November until April or May. Only would take a minute or two in the spring to make sure there is water in the pump.

ComfortablyNumb

Putting it back together took longer than taking it apart. The serpantine belt is behind the mounting bracket for the Whipple Kit. That took a liitle bit to do and a couple of extra hands! Running fine now.