Outboard question

Just wondering if anyone has replaced the Impeller on their outboard themselves, and how difficult it is?

If you call a dealership that handles your outboard motor brand and ask for the head mechanic he might tell you how to install it as you might be buying the part from them. I am no mechanic so not any help there. .
Thanks, Bill

It’s not that difficult. I’ve changed maybe ten impellers in my days. There are little different things for each brand of motor but basically they are all the same.

First you disconnect the shift linkage from near the bottom of the power plant. Then you take all the bolts loose between the lower unit and the shaft. The lower unit should slide down now. There will be a long cooling tube that slides out with the lower unit. Once you get it apart you will see a case that the cooling tube is connect to. Unbolt this case and inside it is the impeller. Take the impeller out and replace it with the new one. Make sure all the fins on the new impeller are curved the same way the old ones were. The new impeller will go in much easier if you grease it before putting in in. Next bolt the case back on the lower unit. Then carefully slide the lower unit back into the shaft making sure the cooling tube slides back into its place. Bolt the lower unit back onto the shaft. Reconnect the shift linkage and test your impeller with a muffler on your engine before taking the boat into the water.

Some engines are a little different so it would help to know what brand and year you have. For example most mid-eighties OMC outboards have a plate on the side of the shaft that must be removed to get at the shift linkage.

I hope this helps and if you have any other questions feel free to PM me.

Gator Hunter

I almost forgot the most important part.

You must look at the old impeller and make sure there are no pieces of it missing. Any missing pieces of impeller must be removed from the cooling system or they may plug it up. This is not a common thing but it does happen.

Gator Hunter

Thanks for the help! The moter I have is a 25 hp. Evenrud, I think it’s about a 1976? One more question, If a piece of the old impeller is lodged into the cooling system. How do you get it out?

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Thanks for the help! The moter I have is a 25 hp. Evenrud, I think it’s about a 1976? One more question, If a piece of the old impeller is lodged into the cooling system. How do you get it out?

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This is a relatively rare thing. I have never seen it happen. Most likely your old impeller is just leaking too much water around it to pump efficiently.

If there is a large chunk of the impeller missing you can flush the cooling system out. I don’t know if your engine has a thermastat but that is where the piece generally gets lodged. You will find the thermastat on the back side of the power plant near the top. It should be a small case held on by two bolts. If you remove this you will find the thermastat and the relief valve. Make sure there are no pieces of impeller in this case. Like I said, this is not common. Also check the cooling tube for any debris.

If you have any other concerns feel free to ask.

Gator Hunter

I pulled the lower unit off the moter. To my suprise the impeller looked like new, the problem is that the part the impeller sitts in and all arround it is full of sand. I’m going to clean it out real good and see if that will fix the problem. I got the moter for free so if I can’t fix it I’m not out $$.