Water pump problem ??

[roehrle]

Just put my 4th water pump in my 1997 9.9hp 4 stroke Evinrude 10FRELEU. I stuck the motor in a tank and started the motor. The flow from the pee tube was great at 3000 rpm but as I slowed down the speed the flow dropped off until there wasn?t any at idle. I ran it at 3000 rpm for about 10 minutes and measured the temperature near the spark plugs using an IR gun and got a reading of 220 F. The book states it should be 160 +_ 15 degrees. The new impeller I put in the pump was extremely difficult it get in. I had to use a hose clamp around the arms of the impeller to get it in which I never had to do with the other pumps I installed. I read some where that some kits were using impeller that were larger than the old impeller and I was wondering if this was my problem. The impeller is apparently working at high speed so why would an over size impeller not work at slower speeds ?? What would cause the flow to stop at slower motor speeds ??
Any suggest would be welcomed.
Evinrude 10FRELEU

 

[racerone]

The impeller is installed on the shaft.----Then ensure that drive pin is in place.---Then lower the housing down while turning the shaft.-----Nothing to it at all.-----Are you using a factory impeller ?------Is water in your test bucket 6 to 8 " above the pump?

 

[roehrle]

Yes the impeller is on the shaft and the pin is in place or I would not get a flow from the pee tube above 3000rpm. This is my 4th replacement so I think I have all the elementary procedures correct by now. This is something out of the ordinary like if they sent me the wrong impeller in the Sierra kit 18-3327, or maybe a blockage somewhere.

 

[racerone]

Good luck with the project.

 

[Crosbyman]

remove the gear case/pump assembly remove the prop and put the gearcase it in a bucket full of water

Rotate the drive shaft with a big drill to see if the pump is pushing water out at lower rpms as it should

 

[flyingscott]

What about your thermostat

 

[roehrle]

Removed thermostat and the result was the same. Then took the pump out again and everything appeared to be OK. Only thing was that the bottom plate that the impeller is on was like a mirror were the impeller was rotating. When I compared the old impeller with the new there wasn't a noticeable difference in size but I still had a difficult time getting the impeller back in the cup again. Had the use the hose clamp technique again...

 

[racerone]

No, you put the impeller on the shaft first.---Then lower the housing down while rotating the shaft !

 

[roehrle]

To Racerone
If you take a look at the attachment from the Evinrude service manual, you will see that it does not say anything about putting the impeller on the shaft first..
at #2 it states
Lightly coat the impeller cup with oil with a CW rotation install the impeller (In the Cup )
#9 States
Slide the housing (containing the cup &impeller) in position e.t.c

 

[hardwater fisherman]

Both of my omc service manuals say to do as racerone says. I did it like you twice before I got my manuals and it is much easier to do as racerone has told you.

 

[Fed]

Interestingly you seem to have changed your book instructions from CCW to CW?

Good luck with the project.

 

[roehrle]

Fred:
Sorry about the missing a "C" in "CounterClockWise" but I was trying to save some time typing out CounterClockWise.
.Don't think missing the "C" in the statement changes the fact that my book states to install the impeller in the cup and then on the shaft. Step #2
To Fisherman
Were your two manuals for my 4 stroke 9.9 HP motor ? Don't you think I'm better off using the instructions written for the motor I'm working on ??
It is a lot easier with the impeller in the cup and the slot for the key aligned to receive the key held in place with grease..
Step #7
Apply OMC Needle Bearing Assembly Grease to the impeller drive pin and position it on the flat of the drive shaft

I really appreciate you guys trying to help me out..I think I have a problem with the impeller , probably due to its stiffness, that won't allow a normal installation into the cup.I have had years of experience working on cars and the last 15 years since retirement on boat motors..There is no way this impeller could go into the cup the way it has been suggested.

 

[roehrle]

Apparently the difficulty of getting the impeller in the cup wasn't the cause of my poor pee stream at low rpm's problem. The pee stream is now working great. The problem turned out to be that the copper water pipe wasn't properly in place at the upper end of the pipe. My motor has the extended 15" section that I never had removed to change the grommet at the upper end of the water pipe. This year I must not had a good connection. I removed the extension and the grommet appeared to be in good shape. The two grommets that came with the kit didn't look any thing like the one I removed so I decided to put the old one back after a clean up and a fresh coating of sealant..The grommet ([FONT=Arial, sans-serif]Sierra International 18-2392 Marine Grommet for Johnson/Evinrude Outboard) is the one I decided not to use. It may fit in the housing bottom hole but I don't see the need of the flat portion of the grommet. Also I don't see any need for the "ears" on the 2392 grommet in the upper pipe because there didn't seem to be holes inside the place the upper grommet would be installed. If some one has any info on the upper copper water pipe grommet I would appreciate any info you have.. [/FONT]
[FONT=Arial, sans-serif]My final conclusion is that some how there wasn't a good connection of the upper grommet at the upper end of the water pipe what was able to get enough water at high rpm's but not sufficient flow at lower rpm's. [/FONT]