Impeller Replacement?

[GMLIII]

Thanks everybody on this thread! I just bought a 1990 Ski Nautique this past weekend, and this thread helped me diagnose the impeller as faulty. Boat starts easy and idles great, but would heat up to about 180 F really fast. Would then slowly climb to about 200 while idling. As soon as I get moving the temp would start to drop to around 160. This thread convinced me to order a new impeller, and last night I took apart the old one. Safe to say I found the culprit.

My question now, besides checking lines, should I open up the risers to check for chunks? I checked all lines on the vacuum side of the RWP and they didnt have much, but the line directly on the other side had quite a bit. Thanks in advance.

Darn that one is toasted. Glad you changed it out

[Viper_Freak1]

If an impeller shreds like that, do most pieces just continue through the engine and out? How are you supposed to make sure all the pieces came out? It doesn’t seem practical to completely disassemble the engine when most pieces could go through if they are small enough. This is why I change mine every season or 100 hours.


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[wakehead]

Hi guys. I am curious about something for Installation of water impellers. Not all the time to get the blades to align in the same direction when I reinstalll the new impeller. Will al the blades find their right direction naturally ? My local cc dealer said it would not be a problem but I'm curious what everyone's opinion is on the matter.

[charlesml3]

Hi guys. I am curious about something for Installation of water impellers. Not all the time to get the blades to align in the same direction when I reinstalll the new impeller. Will al the blades find their right direction naturally ? My local cc dealer said it would not be a problem but I'm curious what everyone's opinion is on the matter.

Yes. If they're going the wrong way, they'll flip around the second the pulley starts to turn. I actually installed one in "backwards" once to see what would happen. Just twist it in. Coating in dish soap will make it go in easier.

-Charles

[scottb7]

Agree. They'll flip around. I would be pretty suspect of the advice of anyone that tells you otherwise.

[srock]

If it ain't broke don't fix it is the worst internet advice you can receive. I went though the process of 3 hours of limping home from the middle of nowhere (ballast pump feeding engine) searching for broken vanes and overheating issues I could not resolve. It was a frustrating, time consuming waste of time. I will never do that again. I change mine out every 100 hours.

[charlesml3]

If it ain't broke don't fix it is the worst internet advice you can receive.

Agreed. Impellers are wear items just like brakes on your car. They must be replaced regularly. There's no compelling reason NOT to replace the impeller regularly.

-Charles

[j2nh]

PCM has made changing the impeller a breeze. I keep an extra impeller along with a 10mm socket and extension in the boat as part of my toolkit. There is no reason to let a $30 part ruin a day on the lake. And again, 15 minutes of prevention vs hours and the hassle of digging impeller parts out of the engine.

[STSCowboy]

Can someone post a photo of their raw water pump on an 89 2001? I need to verify that the pump on my boat is installed correctly. It seems every photo I see the inlet and outlet are closer to the engine but on mine they are on the far side of the engine. The previous owner said he had replaced the impeller but it was all chewed up. So I just want to verify the correct orientation of the pump when it is reinstalled.

[gun-driver]

This should help

[New2theWoods]

Shredded the impeller on my 99 502 Python-powered SN today. Any tips where to order a new one? There’s no owners manual and I’ve run into difficulties finding parts in the past, from what I’ve read on other forums here there were only 20 or so of these engines put in that year.

[janderton]

New2theWoods Curious, did you find any tips? I also have a 502 Python, and will be replacing the impeller this year. I'd love if there are any good tutorials. If there aren't I may just create my own and post it on PN

[srock]

Those who say if it ain't broke... or wait till it gets hot.... have never chased an overheating problem due to impeller fragments obstructing the cooling. It's even worse if you have a heat exchanger. On the other hand, I never change oil until it gets really low, really dirty, or if the engine locks up.

[bturner]

I used to change the impeller every year and have a whole collection of like new impellers to prove it. Being on a small freshwater inland lake and having a house to hang out at, we only put about 25 - 30 hours on our boat a season. As such I made the executive decision to move to an every other year replacement schedule some 10 years ago.

Oh the audacity of that man, excuse me a moment while I clutch my pearls.....



You'd think the impellers would be coming out in chunks based on some of the posts you can find on this topic but I'd bet you a Yuengling (and I really like that beer) you couldn't pick out the 1 season impeller from the 2 season impeller from my boat. I can't and I've been replacing these since the 80's.

Boats these days have strainers so picking up a twig or seaweed and having it go through the cooling system is almost impossible, making physical damage a really rare occurrence. The material itself is better than the rubber we had in the 80s and I check my strainer at least weekly to see if I'm picking anything up so I shouldn't be seeing any water starvation or heating issues that would effect the impeller.

Would I tell anyone not to change their impeller if they felt comfort in doing so? Absolutely not, I see no downside to changing it out. Do I feel comfortable with my schedule, absolutely.

[biacs]

Great insight! I think if you get into an older boat you should certainly earn your DIY stripes. Impeller every year or every other year, probably sufficient. When I had first brought home my 2006, the impeller was very much roached, so I changed every year just because I had the time :-)

One thing to mention for the uninitiated, my 2006, the exhaust tubing that run off the engine were smooshed too far up the risers on the block. And left me NO room to change the impeller. I had to unbolt the exhaust risers from the engine and loosen the muffler. It was a real headache.

So if you're just starting to learn to change the impeller, and it seems too snug to get tools in there, you might have to take off the exhaust elbows and scooch the black exhaust tubing down a bit to give you that clearance so you can change it easily each time.