My boat and outboard motor is three years old now and I asked the dealer where I store the boat to change the bottom gear oil, motor oil, fuel filter and the water pump impeller. He emphatically said that it is a lot of work to change the impeller, as he has to dismantle the entire bottom end, and not necessary as long as I always run the motor in the water and the "pee hole" is always working. The manual and everything I have read has instructed to change the impeller each year. Any comments?
Outboard Water Pump Impeller
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It's definitly
definitly not a "simple" job, but it should be done. -The pump keeps working until the day it stops working, and it's not going to fail when you aren't running the motor...which means it is going to fail while you ARE running the motor. Ideally, we want that not to happen, so we change our impellers every so often!
definitly not a "simple" job, but it should be done. -The pump keeps working until the day it stops working, and it's not going to fail when you aren't running the motor...which means it is going to fail while you ARE running the motor. Ideally, we want that not to happen, so we change our impellers every so often!
change it
you can do this yourself if you have any machanical ability at all. I changed my Honda 9.9 in less than an hour. When you buy a new impeller buy 2 and carry a spare. Look in benny's post about his broken off bolt and use a non copper based antisieze compound on the bolts. This is preventative maintenance, if your dealer is emphatic about not changing it I would change dealers too. Thats just plain stupid.
you can do this yourself if you have any machanical ability at all. I changed my Honda 9.9 in less than an hour. When you buy a new impeller buy 2 and carry a spare. Look in benny's post about his broken off bolt and use a non copper based antisieze compound on the bolts. This is preventative maintenance, if your dealer is emphatic about not changing it I would change dealers too. Thats just plain stupid.
To replace or not to replace?
Outboard impellers seldom fail in a catastrophic manner. Unless you run them out of the water they will usually wear down, loosing pumping ability gradually. Even with a broken vane or two you may be able to limp home at reduced power. Also with normal engine use they will last for a long time. The chances of engine breakdown are much greater from a number of other failures than from the impeller. The best advice is to have a backup plan in case of outboard failure to get yourself back to shore. This may be one of the cases where the cure is more onerous than the resulting disease. I don't buy your dealer's response that he doesn't recommend doing it because it is a lot of work but I don't dispute the fact and the wisdom that many mariners will not change the impellers on their outboards until they fail. Don't confuse outboards with inboard diesel engines. I changed the impeller on the raw water pump of the diesel once or twice every year as they seem to wear down much sooner. With the pump being under the water line it should never runs dry but sometimes flow may be hindered by marine grass on the intake strainer. If if you are planning a trip by all means do preventive maintenance and also replace the impeller to minimize the possibility of any breakdown but don't get paranoid about failures as they will happen when you least expect them and if you have a plan or towing insurance you will get through them.
Outboard impellers seldom fail in a catastrophic manner. Unless you run them out of the water they will usually wear down, loosing pumping ability gradually. Even with a broken vane or two you may be able to limp home at reduced power. Also with normal engine use they will last for a long time. The chances of engine breakdown are much greater from a number of other failures than from the impeller. The best advice is to have a backup plan in case of outboard failure to get yourself back to shore. This may be one of the cases where the cure is more onerous than the resulting disease. I don't buy your dealer's response that he doesn't recommend doing it because it is a lot of work but I don't dispute the fact and the wisdom that many mariners will not change the impellers on their outboards until they fail. Don't confuse outboards with inboard diesel engines. I changed the impeller on the raw water pump of the diesel once or twice every year as they seem to wear down much sooner. With the pump being under the water line it should never runs dry but sometimes flow may be hindered by marine grass on the intake strainer. If if you are planning a trip by all means do preventive maintenance and also replace the impeller to minimize the possibility of any breakdown but don't get paranoid about failures as they will happen when you least expect them and if you have a plan or towing insurance you will get through them.
Water Pump Impeller
Thanks to all of you who responded. I appreciate the advice. I might try to change the impeller myself, if I get a good reference manual or web site reference. The feedback is very much appreciated.
Thanks to all of you who responded. I appreciate the advice. I might try to change the impeller myself, if I get a good reference manual or web site reference. The feedback is very much appreciated.
Barry, what type outboard do you have?
Let us know, there is a good chance someone here may have replaced the impeller on the same type of outboard you have and can walk you through it. Here was the procedure for my Honda: 1) Remove pin connecting shift lever mechanism to the shift rod 2) Remove bolts supporting lower unit except for two left just slightly threaded to support the unit 3) Gently wiggle lower unit until it started to separate 4) Remove the last two bolts and lower further 5) Unbolt impeller covers and remove old, cracked and twisted impeller noting direction 6) Remove gaskets noting orientation 7) Clean area and lift up and out lower drive shaft and remove old seal 8) Clean area again and install new seal and drive shaft 9) Install new gaskets 10) install new impeller into cover with vanes turned in correct orientation 11) slide covers back on and bolt back on, dont forget anti seize 12) Gently slide lower unit back in place making sure drive shaft, water hose, shift rod all align into position 13) Replace and tighten lower unit bolts - dont forget anti seize 14) Reconnect connecting pin for the shift mechanism I'd have to guess it's not that much different for other manufacturer's outboards. Your mechanic should be able to show you an exploded view of the lower unit to give you an idea of what's going on. My local Honda dealer encouraged me to do it, said it was fairly straight foward, and even showed me diagrams from his computer. He's a little more expensive than ordering parts from the internet, but with that kind of service, he'll always have my business. BTW -something to think about - an impeller kit for a small outboard is a lot cheaper than the deductible on a tow, don't wait until it fails. Manny
Let us know, there is a good chance someone here may have replaced the impeller on the same type of outboard you have and can walk you through it. Here was the procedure for my Honda: 1) Remove pin connecting shift lever mechanism to the shift rod 2) Remove bolts supporting lower unit except for two left just slightly threaded to support the unit 3) Gently wiggle lower unit until it started to separate 4) Remove the last two bolts and lower further 5) Unbolt impeller covers and remove old, cracked and twisted impeller noting direction 6) Remove gaskets noting orientation 7) Clean area and lift up and out lower drive shaft and remove old seal 8) Clean area again and install new seal and drive shaft 9) Install new gaskets 10) install new impeller into cover with vanes turned in correct orientation 11) slide covers back on and bolt back on, dont forget anti seize 12) Gently slide lower unit back in place making sure drive shaft, water hose, shift rod all align into position 13) Replace and tighten lower unit bolts - dont forget anti seize 14) Reconnect connecting pin for the shift mechanism I'd have to guess it's not that much different for other manufacturer's outboards. Your mechanic should be able to show you an exploded view of the lower unit to give you an idea of what's going on. My local Honda dealer encouraged me to do it, said it was fairly straight foward, and even showed me diagrams from his computer. He's a little more expensive than ordering parts from the internet, but with that kind of service, he'll always have my business. BTW -something to think about - an impeller kit for a small outboard is a lot cheaper than the deductible on a tow, don't wait until it fails. Manny
It's A Nissan 9.8 Four Stroke
Hi Manny, It's a 2005 Nissan Four Stroke. I haven't found too many places that want to work on them, but I am up to the challenge. Your description doesn't seem too complicated. I try to do all the work on my vehicles, unless it involves emissions, so I guess this isn't going to be too difficult. Thanks for the feedback, Barry
Hi Manny, It's a 2005 Nissan Four Stroke. I haven't found too many places that want to work on them, but I am up to the challenge. Your description doesn't seem too complicated. I try to do all the work on my vehicles, unless it involves emissions, so I guess this isn't going to be too difficult. Thanks for the feedback, Barry
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