Water Pump change

How difficult is it to change the water pump on a 1988 johnoson 70hp? Any suggestions or tips? The motor was given to me and it runs fine but it set up for over 2 years and i would like to do some prevenitive maitnance starting with the water pump. Anyting else i should take care of?

Re: Water Pump change

I never did it on a 70 H.P. motor, but I did it on an 8 h.p., a 25 h.p and a 40 h.p., and I found that they were all similar, just bigger parts actually. The job was not too difficult at all for me. The toughest parts of it was getting the water tubes started back into the grommets when putting the motor back together, and hooking up the shift linkage together. This was tough for me only because I have some really big hands I think. If you have smaller hands, you should not have a problem. Always make sure that you change the grommets, seals and gaskets while you are in there changing the impeller, and inspect the housing real good, checking inside the tubes that run through it too so to be sure that no pieces of a broken impeller are stuck in the housing somewhere. Always turn the driveshaft clockwise too when installing the pump to make sure you are not pinching the impeller vanes between the two halfs of the housing.

You turn the driveshaft 'clockwise' when putting the two halfs of the housing together. When looking at the vanes from the 'bottom' side, the impeller turns 'counter clockwise' So make certain the vanes start out in the right direction!

ALSO, you would want to check the oil in the lower unit gear box. Drain it into a container. Check the amount of oil that was there to see if the level was proper. Check for metal shavings, and check for water in the oil. See if the oils is 'milky ' looking. If it is, you have water coming into the oil from somewhere. USUALLY it is from the prop shaft seal, however, it could be from a differant area. Replace the seal. You will need to get it pressure tested to find a leak unless you take the chance and just replace the prop shaft seal (easy and cheap).

Check your spark plugs to see their condition. Clean and regap them if they look good or replace with new ones. Check all wires around the power head and down to you controls if you have any. Repair/replace any bad wires. I like to add a product called "sea foam" to my gas at least once a year. Works wonders for smooth running.

Re: Water Pump change

Easy peasy, that's how hard it is. I've done them on a Rude 140 by myself, so the 70 will be no-brainer. I found out, over the years, that most of the "daunting projects" I have attempted weren't any where near daunting when I was finished. It'll be the same for you, I'm sure.

As to what else to do, I'd change the lower unit fluid, of course. I'd also want to run a compression test and a spark test so I know where I stand (these before anything actually). And then I'd inspect the complete fuel system, to include every little fuel line hose on the powerhead all the way back to the fuel tank, replacing any length that looks worn or cracked. Again, that's one of those things that sounds daunting, but it really isn't. When was the last time the carbs were cleaned? If you don't know or it's been a bit, I'm sure they could use it and it might prevent being towed back to the dock.

To give you an example, I just picked up my current boat a couple of months ago and it spent 10-12 days in my garage while I was getting it "ready". And that included a steering cable replacement that was a 'must-do' that caused me fits to start. I've just always felt it was better to go through all systems and fix whatever's broken BEFORE it leaves me stranded. A member named, JerryJerry has in his signature line "If your outboard doesn't start within a few seconds, something's wrong" and I think that sums up boating and boat motors nicely. We tend to "put up" with some things or "put off" others, and then, oddly enough, we complain about the manufacturer, lol. Spend a little time getting it ready and she'll give you tons of happy memories in exchange.

Re: Water Pump change

Thanks guys,

I've already cleaned the carbs changed spark plugs and ran a compression check; they were all within 10% of each other. Like to think i'm mechanically inclined but molstly worked on 4 wheeled vehicles. Just didn't want to jump into a task blind.

Re: Water Pump change

When I got my 1st boat and did my 1st water pump, I'd never turned a wrench on anything, so you'll be fine. Definitely want to change the LU fluid especially since you'll have the leg off anyway. Easier to do when it's sitting in a vise anyway. Good luck!

Re: Water Pump change

I removed the lower unit on my similar vintage 60 recently. Check with the book that you find ALL the bolts. If the lower unit doesnt part easily, there is another bolt somewhere. There was one under the adjustable trim 'fin'. If it has been long since the bolts were removed, GENTLE heat will help. Putting the bolts back with copper grease is a good idea. Apart from that, it is an easy enough task.