25 HP Johnson repairs

[smackover]

1. I am going to change out the water pump impeller on my 1988/25hp
Johnson OB.

Can someone give me instructions on how to ?

2. Want to replace the seal on my lower unit...expect it is on the
propeller shaft.

Can someone give me instructions on how to go ?

Regards

Smackover

[smackover]

any help here ?

[ready2fish]

lets see if i can help

i asked the same question last year and was told to go to "the marine doctor" well i did and was told you would need a special tool to remove the nut on the output shaft, its like a spanner type wrench. i never replaced the seal i believe my problem was i was using to much oil in my gas and extra oil leaked out of the exhaust port and ran down by my prop shaft. I still need to do my water pump, if you go there they have a link to a video on how to do this also do a search on a user name "jimv" and you will see the topic on replacing the shaft seal

sorry i cant be of any more help

also here is there addy
http://www.themarinedoctor.com/cgi-bin//YaBB.pl

[Scrapper]

That one is tricky..most water pumps are very simple to do. The only thing about this one that is tricky is to unhook the shift linkage you go through the water inlet on the lower unit. It has two nuts...one of which is a jam nut. You will take these apart to get the lower unit off. If you jerk on it you will pull the linkage too high and will have to loosen off the output shaft nut. These loosens the carrier and the rod will fall back in there. Not a big deal though...just dont jerk on it trying to get it off.

There is also a little black plastic keeper down there...you will need to buy one of these when you put it back together. You'll see it when you pull the lower unit off of the midsection and the rod comes out. About 3 bucks at the parts store. If you'll look through this forum or may be in the main forum I posted a lengthy post about changing one out. May help some. Its really straight foward...just take your time. I would recommend buying the kit...not just the impellor. The kit comes with everything...that way everything is new...not just the impellor...not a neccessity, but added insurance.

Little hint...when putting it back together...use liquid hand soap on all the rubber parts..impellor/seals/etc...this will help everything go back together a bit easier.

[ready2fish]

thanks scrapper for the tips

Well i went ahead and done mine today but mine is a merc, The impeller was indeed bad on mine so that made me feel good about having to do the work, the soap made it really easy . I would rate the difficulty about 2 out of 10, the only issue is i didn't have an extra pair of hands that would of helped while putting it back together. One tip my parts dealer told me to watch for a washer on the shift shaft, he said it used to push the gear lever back in neutral

[smackover]

Thanks for the advice and schematic......came apart just like you said it would.

Will ggo back together as soon as NAPA gets parts in

Regards

Smackover

[RCC]

Just want to say thanks for the info even though it has been 4 years since this thread started. Here is what I ran into with my 1999 25 hp Johnson this week. No water would come out of the tube at the top of the motor. I suspected water pump since I had never changed it. The service manual said to make sure there was no paint on the shift linkage. I DID NOT DO THIS. The shift linkage came apart OK and the foot came right off. I removed the housing and the water pump impeller showed very little wear which indicated that I probably had some other problem. I had previously ran a piece of weed eater line about a foot long up into the tell hole and could not feel any blockage. With the foot off, I connected the water hose to the tell hole and no water came out the tube in the foot. I then pulled the rubber tube from the tell hole from the block connector. I found the rubber tell tube blocked about 3 inches from the motor. I punched this blockage out with the weed eater line and connected the hoses back up and ran water from the tell hole back through the tube that connects to the impeller housing. I then reassembled the motor with a new impeller and found that, even though I had removed the foot with the shifter in forward, the foot was actually in neutral. THE UNREMOVED PAINT had bound the compression nut to the shaft and as I turned the nut, it also turned the shifter linkage causing the linkage to be out of adjustment. One I figured out what had happened, it was a simple matter to clean the paint off the shaft, put the shifter in neutral, find neutral in the foot and adjust the linkages where the compression fitting would fit.

Now that all is well, I would like to say thanks for the tips. The dish washing soap was a life saver. Other than the mistake I made on the linkage, it was all pretty well straight forward, however, before disassembling the motor, make sure there are absolutely no blockage in the tubes.