replacing the impellor/waterpump

[darknight]

hi guys, i must say i joined this forum because of looking through the posts and seeing how helpful and friendly you all are.
i may be on the other side of the atlantic (uk) but hey.
ok my question is this, i have a 71 25hp evinrude, bought her second hand, replaced the plugs, fuel lines etc etc, started her up, ran well a bit smokey, but i think i added too much oil to the mix so not a big deal, i am gonna set up the carb once this job is done.

now she had no water coming out the exhaust, so, i droped bottom end of to replace impeller, saw the water pump body wasnt good either so im going to replace that as well, but what stumps me is.... when the impellor and body are in place, and pushed up onto the shaft, just before bolting up, how do i make the key-way on the shaft make sure its in the impeller groove?
also is there a thermostat on these engines? if so if you could point me in its direction, as i would want to replace that as well to be sure.
thanks for all your help

 

[lindy46]

Re: replacing the impellor/waterpump

The impeller housing won't go all the way down unless the key is aligned with the impeller. However, I usually turn the impeller in the housing until the groove for the key is pointing toward one of the bolt holes in the housing. I then align the driveshaft so the key is pointing toward the matching bolt hole in the base. This will make it a little easier to get everything to align. Thermostat is located at the top of the block, under a little triangular-shaped cover with three bolts.

 

[F_R]

Re: replacing the impellor/waterpump

The impeller housing won't go all the way down unless the key is aligned with the impeller. However, I usually turn the impeller in the housing until the groove for the key is pointing toward one of the bolt holes in the housing. I then align the driveshaft so the key is pointing toward the matching bolt hole in the base. This will make it a little easier to get everything to align. Thermostat is located at the top of the block, under a little triangular-shaped cover with three bolts.

And, what I do is place the impeller on the shaft first. Then you Know it is on the key. Then lower the housing down over the impeller as you rotate the shaft clockwise. That will bend the blades back in the proper direction as the housing squishes down over it. Easy no-brainer.

 

[darknight]

Re: replacing the impellor/waterpump

thank you for the info guys, i dont seem to have an impeller that needs its blades bent round, the one i have just seems to sit in the housing, with a little space around it.
cheers

 

[Rick.]

Re: replacing the impellor/waterpump

Sounds like you may have the wrong impeller there. It should reach the outer circumference of the body and then some. Rick.

 

[darknight]

Re: replacing the impellor/waterpump

ah, thanks for that, thought i was just lucky to have an easy fit..
ill get another one to check, and i just found the thermostat, doesnt look like that was working either...ah well back to the shops.

 

[lindy46]

Re: replacing the impellor/waterpump

Those impeller blades should be longer than housing and a bear to get all bent into place. It is a tight fit.

 

[darknight]

Re: replacing the impellor/waterpump

well ive ordered them all up now, so just waiting for the postman,
i need a grommet for the water pipe, oil seal for the shaft into the lu, and a themostat, then i can put her all back.. cheers for the help all