How to change impeller?

Discussion in 'Classic Sea Rays' started by muskokamarc, Jun 20, 2019.

  1. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    Hey there - Marina said my impeller needs to be replaced. I was wondering if its a difficult part to change myself.

    Does anyone have a video on how to do so?

    1987 SeaRay Monaco Cuddy (230hp Alpha One Sterndrive)

    Thanks
     
  2. techmitch

    techmitch Well-Known Member GOLD Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    Here ya go. lots of useful info. on this site. http://www.mercstuff.com/waterpumpinst.htm
     
    muskokamarc likes this.
  3. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    Doesn't look extremely difficult but it would need to be out of the water and I don't have a trailer. Will probably just get marina to do it. Shouldn't be too much $.
     
  4. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    Marina did say that I could still drive the boat this weekend without changing it, but just shouldn't leave the boat in neutral for much time. Can someone explain how that makes sense?
     
  5. BillK2632

    BillK2632 Well-Known Member GOLD Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    On an Alpha (Gen I or Gen II) the waterpump is driven by the driveshaft in the outdrive - the shaft spins all the time so the pump runs in F-N-R. Only reason I can think of is that with the impeller damaged/worn it is not pumping enough volume at the low RPM in neutral. As you run the boat and the RPMs increase, the pump speeds up and pumps more volume. If you see the engine temp rise abnormally in neutral this would be the reason. Another indicator that the pump impleller is a end of life is the risers are getting too hot - normally they should be very warm, but not so hot you cannot lay your hand on them.
     
    muskokamarc likes this.
  6. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    Thanks. That makes sense.

    If for whatever reason i end up in neutral and the boat shuts off because it overheats, would that be catastrophic damage? Or would i just need to wait until it cools off to start again?
     
  7. techmitch

    techmitch Well-Known Member GOLD Sponsor

    May 1, 2008
    Chesapeake Bay, Middle River/Frog Mortar Creek MD.
    1999 270 DA
    Twin 4.3s W/Alpa I Gen II's
    Didn't the marina give you a price when they told you it needed an impeller?
     
  8. BillK2632

    BillK2632 Well-Known Member GOLD Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    Yes, if the engine shuts down form an overheat, you probably have caused some damage. Watch the temp guage, depending on the type thermostat you have it should run either around 140deg or 170deg - if the temp starts rising much above those temps you should not run it. 200deg or even 220deg doesn't really hurt the engine itself, BUT with the way a boat cooling system works, the exhaust system is not designed to handle that kind of heat. If you know the impeller is bad or close to failure replace it - an old impeller can fail catastrophically, going from some cooling to no cooling. In the process it usually sends little peices of the failed impeller throughout the cooling system - this causes more problems even after you replace the impeller if you don't get all those pieces out. The imellers on the old Alpha I Gen I's like yours are small and in a plastic housing, they have a history of not lasting very long - a lot of owners replace them annually. My Alpha I Gen II on the other hand has a larger impeller in a SS housing - they easily last 3-5yrs.

    Change the impeller - it's not worth the risk of the damage it could cause.
     
  9. JimG

    JimG Well-Known Member SILVER Sponsor

    Nov 4, 2008
    Southern WV
    2007 310 DA
    Kohler 5ECD
    Twin 350 Mags
    Raw Water Cooled
    V-Drives
    Assuming you are somewhat mechanically inclined, you could actually do it in the water. I would pick a shallow spot where I could stand in the water. Trim your drive all the way up and remove the lower unit, lift it up on the boat or the bank, and change it. You don't have to pull the prop or drain the oil as depicted in the link Mitch provided... that was for a complete servicing job.
     
  10. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    $40 for the part and labour. Scheduled for the impeller to be changed next week. Just wanted to take it out this weekend as I had some people coming up to the cottage.
     
  11. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    Really? It is actually sitting up on a lift so that might make it easy enough.
     
  12. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    Do you mind indicating which numbered steps i have to complete looking at the link: http://www.mercstuff.com/waterpumpinst.htm
     
  13. JimG

    JimG Well-Known Member SILVER Sponsor

    Nov 4, 2008
    Southern WV
    2007 310 DA
    Kohler 5ECD
    Twin 350 Mags
    Raw Water Cooled
    V-Drives
  14. BillK2632

    BillK2632 Well-Known Member GOLD Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    If it has not started overheating yet and the marina is recommending the impeller replacement due to age, the you probably will be ok running it some over the weekend.

    Jim - are you sure about the oil? I've never actually change the impeller on a Gen I so I can't say, but I have had changed several in my Gen II and there is an oil passage between the upper / lower that will leak oil everywhere if you don't drain it first. Maybe a Gen I is different.
     
  15. JimG

    JimG Well-Known Member SILVER Sponsor

    Nov 4, 2008
    Southern WV
    2007 310 DA
    Kohler 5ECD
    Twin 350 Mags
    Raw Water Cooled
    V-Drives
    Actually Bill I was not sure... thanks for catching that. To the OP - Drain the oil!

    Here's a great video on the Gen I:
     
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  16. BillK2632

    BillK2632 Well-Known Member GOLD Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    So in full disclosure - first time I changed the impeller on my Gen II forgot to drain the oil and made a huge mess.:)

    I always pull the drive, put it on a stand makes things much easier. I tried just dropping the bottom half once and it was more difficult for me to get it all back together while trying to hold the bottom half, start the bolts etc. Also, pulling the drive gives you a chance to inspect the bellows, gimbal bearing, lube everything and check the engine alignment.
     
  17. muskokamarc

    muskokamarc Member

    99
    May 28, 2018
    Muskoka/Toronto
    1985 Sea Ray 210 Monaco
    2007 Sea-Doo Wake
    1996 Starcraft Fishmaster
    230HP Alpha One
    Question, where/what are risers?
     
  18. BillK2632

    BillK2632 Well-Known Member GOLD Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    The exhaust elbow that "rises" up from the exhaust manifold and connects to an exhaust pipe that goes out through the transom. There is one on each side of the engine if it is a v6 or v8, inline engines would only have one. The riser is the point in the exhaust system where the exhaust gas mixes with the cooling water and exits the engine. This is a common failure point on boat engines, especially ones run in salt water - freshwater they generally last forever. When they fail it can allow water to run back into the engine through the exhaust manifolds.

    In this picture, the triangle shaped thing is a manifold, the tall piece on top of it is the riser. Different models can look a little different, but accomplish the same thing. Your SeaDoo has one, just smaller and shaped differently. If the engine is cooling properly you should be able to lay your hand on top of it, it get's hot, but not burning hot.
    https://www.google.com/search?rlz=1...j0i8i30j0i24._8Qh6Tb3aug#imgrc=s5SUvbGMM5WkMM:

    Here is an overview of how a Mecruiser sterndrive cooling system works:
    https://www.boatpartstore.com/iocooling.asp
     
    muskokamarc likes this.

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