after changing impeller ???

[MATTT]

Hello, Every one.<br /><br />I have a 1991 40hrs johnson.<br /><br />If I could drop the lower unit and then install new impeller. Do I have to replace the two seals also ? Or is that it, just replace the impeller. How do I put the lower unit back on ? How involve is it, Do I have to worry about puting the shift rod back to the right place ?<br /><br />Thanks, again.<br /><br />Mattt.

 

[12Footer]

Re: after changing impeller ???

Hi, Matt. You can't normally tell by eye, if the seals need replacement. The best way to tell,is with vaccum and pressure testing the lower unit after the new impeller has been installed, and you are ready to bolt it back on.<br />Most guys don't have the equipment for this, but a bicycle pump with a built-in pressure gauge,hooked-up to the vent or fill screws, can work as a makeshift pressure tester. Pump it up to 5-10PSI,and watch for a drop in pressure on the gauge. If it drops, stick the entire l/u in a garbage can filled with water,and pump it up again. Look for the bubbles. This will show you the bad seal or seals.<br />The lower unit goes on in the reverse order of how it came off,pretty much. Just be very carefull when lining everything up.<br />My advice is to get the shop manual before starting this. It will pay for itself, i promise.<br />You will most-likely spend an entire weekend,book in hand, to remove it, replace the impeller,and remount it. But less than 1 to 1.5 hours any time thereafter.

 

[mworthan]

Re: after changing impeller ???

Matt,<br />I've built and repaired boats for maybe 8+ years, but never serviced an outboard till this past weekend. Bought an impellar kit with the seals and housing for my 115 Johnson and a Clymer's manual and did the whole job in an hour. Real easy, don't worry. Get a manual though.

 

[MATTT]

Re: after changing impeller ???

I do have an evinrude/johnson outboard shop manual, 2-300 hp 1991-1994. Is it just me or the pictures and desc in the shop manual are so bad ?<br /><br />mworthan, you mean I have to change the whole thing not just the impeller ? I have to replace the housing also ? I heard that a lot of people have problem dropping the lower gear case becuase of the shift rod. Any easy way of doing that.<br /><br />Thanks, for your info.<br /><br />Mattt.

 

[mworthan]

Re: after changing impeller ???

No you don't have to change the entire assembly, but this was a new (to me) motor and for $55.00 I said why not. The kit came with all of the replacement O-rings and gaskets including the drive shaft and linkage gaskets...very complete.<br /><br />The linkage connection on my 81 Johnson V4 is a little hard to get to. I had to use a long flat blade screwdriver to back out the screw until the linkage rod turned loose. Not too bad. The worse thing about getting to it was the vacuum lines that were in the way. The screw didn't come out completely (maybe it is held captive). I just backed it out until the rod popped loose. Good luck.

 

[jm]

Re: after changing impeller ???

MATT<br /><br />I just replaced the water pump on my 63' Johnson 40HP. The job sounded a lot more intimidating than it really was. I am very new to outboard motors, this was my first repair and it took about 4hrs only because I stopped to get more advice from the board because the lower unit wouldnt drop easily after all the bolts were removed. The guys here built up my confidance and told me to use a little more force on it, they were right dropped in 5 mins. Only took another 15mins to replace the pump and 15 to put the lower unit back on.<br /><br />Advice from my experiace is to spray a little WD40 on the bolts before removing them. Makes the job soooooo much easier and you'll have less of a chance to strip them.<br /><br />Go for it!