1975 Johnson 25 hp impeller problem

[jonmac3569]

Hello, new to this site. I recently inherited a 25 HP Johnson from my grandfather. The motor had not been run in about 8 years or so. I rebuilt the carb, changed the plugs, changed the lower unit oil and changed the fuel lines. Most recently I just got through replacing the impeller.

In the service manual it says after putting in the new impeller, "you turn the driveshaft clockwise to position the impeller in the correct direction inside of the impeller housing". after doing this I could still turn the driveshaft by hand. After I screwed down the 3 screws on the impeller housing (see pic) I can not turn the driveshaft. (by hand or with a pair of channel locks) I am pretty sure I could spin it by hand when I took it out originally. Also if I only turn the screws down about three turns to where I can still spin the driveshaft and then put the lower unit back in (align the splines) The pull cord will only pull about half way, and it is not smooth like it was. Seems like it is hanging up.

To be able to spin the impeller easily, i would have to only turn the impeller housing screws down maybe 2 turns (with 8 or 10 turns being tight). they would not have any tourque on them at all. I have tried lubing up the impeller with vaseline which was recommended to me. Any other ideas?

Thanks in advance.

 

[cjr1971]

Re: 1975 Johnson 25 hp impeller problem

The Power head only turns 1 way. So in forward or revese it is only turning one way. I've never heard of lubing with vasiline.
the water lubes the impeller. did you check the wearplate under the inpeller ?

 

[jonmac3569]

Re: 1975 Johnson 25 hp impeller problem

Well it figures that as soon as I posted this problem that I would find my answer. I took it apart again and found that the pin that holds the impeller in place was not in the grove correctly. I have taken it apart 3 times and somehow not noticed it.

I have it back together now and it seems to work properly although it still seems like the pull crank is still not very smooth. Maybe it is just because I have it mounted up high on the work bench and I don't have the leverage I would have in the boat.

 

[leda259]

Re: 1975 Johnson 25 hp impeller problem

i did the same thing with the pin thing. the impeller doesn't seat all the way down if the pin slips.

do not go crazy pulling the starter cord without water in the pump. the water lubes the impeller. since you vaselined it, i wouldn't worry too much but get water to it before you play around too much. get one of those rinse fittings and hook it up to a hose. fire it up. easier working in the driveway than on the yacht.

sounds like you have good compression. if you pull the plugs, it should turn easier, but still heed the above warning.

 

[jonmac3569]

Re: 1975 Johnson 25 hp impeller problem

Thanks!