Need help with a 1988 Nissan 5hp (NS5B)

[BloodStone]

Hello;
Back in February I purchased a 1988 Nissan 5hp (#NS5B). Looked great, started great, great compression, lower unit oil was great etc.. Anyway, the catch is..It's not pumping water (feel air but no moisture). I removed the lower unit, took off the pump housing bolts & low & behold there was the impeller..in pieces (3.5 blades out of 5-not good!). Found a small piece of the impeller & removed it. And Naturally, I replaced the impeller, put it all back together (what a royal pain in the arse that was!), put it in a 35 gallon barrel, filled it with water, started the motor &... TA DA- NOTHING! Lots of air but, again NO water. After talking again to the local Nissan dealer (& wondering if perhaps I put the impeller in upside down :facepalm: ), I took out the impeller, turned it around & put it all back together again. Started it & ZIPPO! Lots of air but STILL no water :grumpy: . The water pump housing is in great shape (ditto for the wp gaskets). And I blew a small amount of air through the motor (20lbs or so). So someone PLEASE tell me they have some idea/suggestions what in the world is going on? Don't really have the ca$h to doll out for the marina/mechanic (@$125.00hr) to fix it.
And yes, I made sure the tiny impeller chuck/key was properly placed on the shaft both times.
Thanks in advance.
P.S. I looked on both here & Tinboats about my problem (before posting). Found some posts on Nissan WPs & Impellers but not specific enough to tell me what to do about this exact problem).

 

[Sea Rider]

Re: Need help with a 1988 Nissan 5hp (NS5B)

To know water pump pumps good amout of water, place a drill on upper drive shaft, place LU on a bucket filled with water, and check if wp is pumping good amount through upper grommet. You could have a miss match connection between water pump upper grommet and water tube ?

Happy Boating

 

[pvanv]

Re: Need help with a 1988 Nissan 5hp (NS5B)

It is guaranteed that you are not pumping to the power head. You are feeling exhaust coming out of the pee tube. Could be a wrong impeller (no, you can't put it in upside down -- whoever told you that is mistaken), or a worn wp cup or plate, or missing impeller key, or a water tube that is not inserted in the pump, or a missing grommet at the wp tube, or some other items. Incidentally, never replace just the impeller; always do the complete wp kit -- pumps better and lasts longer.

 

[BloodStone]

Re: Need help with a 1988 Nissan 5hp (NS5B)

Update:
After many trials & tribulations (aka taking apart the LU & putting back together 4-5 times), I am happy to report, that I FINALLY got the motor fixed & all is right in the fishing world. :triumphant:
On a side note; I think, no I KNOW, it would've been an easier endeavor had I had some sort of service manual given the fact that this was my 1st ever impeller/WP repair. Also having a friend assist (I.e an extra set of hands & eyes) doesn't hurt none either.
Thanks again to all those who responded. :tea:
(now, onto the next project :nevreness: )

 

[pvanv]

Re: Need help with a 1988 Nissan 5hp (NS5B)

Amen.

That is why I typically recommend referring to the Factory service manual. Our techs use it, so why shouldn't a DIY person use it as well?