New Impeller Not Working

[gghamm]

I'm new the the forum, and I've seen some good answers to peoples questions and am hoping someone can help me out. I have an 1971 85 hp evinrude, electric shift. I've been fixing/replacing parts on and off since I got it last summer, and recently bought a new impeller to install in the lower unit. I've had my lower unit on and off over half a dozen time now trying to get it to work. I use a set of cups on my hose to run the motor in my driveway, and since installing the new impeller, I'm getting nothing out of the pee hole. It would work fine in the driveway before the new impeller, but when out on the lake, it would not get enough water aat high RPMs, was good at low RPMs though.

I've had the new impeller installed the new impeller in both directions multiple times, and I can't get anything. Any suggestions anyone can give me as to what I can check would be very helpful.

 

[KYHunter2]

Re: New Impeller Not Working

Make sure the that the impeller drive pin.

Is not worn , or missing.

Also that the water tube, that goes into the housing is connected properly.

Check housing for cracks, etc.

Also the seals and grommet.

Your motor has a tell tale ? Or are you referring to the exhaust relief holes , on mid-section?

If it has a tell tale installed , the line may be plugged.

If you really want a good way to monitor your water pump , install a pressure guage.

The tell tale only tells you its pumping .

A guage can tell you if the pump, is getting worn or not.

KYHunter

 

[Solittle]

Re: New Impeller Not Working

You stated "I've had the new impeller installed the new impeller in both directions multiple times, and I can't get anything." This makes me think that you somehow did not get *** put together correctly. Did you use the OMC manual for your engine? If not - - - - - -

 

[gghamm]

Re: New Impeller Not Working

Make sure the that the impeller drive pin.

Is not worn , or missing.

Also that the water tube, that goes into the housing is connected properly.

Check housing for cracks, etc.

Also the seals and grommet.

Your motor has a tell tale ? Or are you referring to the exhaust relief holes , on mid-section?

If it has a tell tale installed , the line may be plugged.

If you really want a good way to monitor your water pump , install a pressure guage.

The tell tale only tells you its pumping .

A guage can tell you if the pump, is getting worn or not.

KYHunter

I know the drive pin is all set and the housing has no cracks. I've been killing my hands making sure the ware tubes are lining up right. I am referring to the tell tale, and I'm fairly certain thats not plugged, because when the lower unit is off, I can put my hose directly on the starboard side water tube, and the pressure from the hose gets water pushing out the tell tale with a nice steady stream. I guess I'll go through the seals again, I wish there was an easy way to tell if those were the issue while the lower unit is off the motor, but maybe I'll see something tomorrow. Thanks.

 

[hunt-fish.com]

Re: New Impeller Not Working

Check the water intake grommet if it has one. I just had that problem with mine today. When installing the lower unit the water intake grommet turned sideways, twice! Blocking the water flow from the impeller. No water through the telltale either. I put some dish soap on it to make it slippery and she went on fine. Hope this helps.

John

 

[imported_Lasse]

Re: New Impeller Not Working

In what condition was the old impeller when you opened it for the first time? I had a similar problem with 9.8 -72 Mercury. I also opened waterpump for several times and tried everything I even tried to rotate the shaft with drill and see if pump is really pumping, it was, and I had also secured the pump attaches when lower unit is on it`s place.I also tried attaching a gardenhose to waterpipe going up to the powerhead when the lower unit was off and waterflow was good so there was no rubbish etc. blocking the cooling system. The real problem was a burnt exhaust gasket that leaked gasses into the coolingblock where they rised up and stopped the waterflow trough the pee-hole. So all the cooling water exitted through the prop with exhaustgasses what I couldn`t see. So if you haven`t never seen cooling to work properly in that motor, or it has overheated before you got it, it may be a burned gasket that is causing cooling not to work properly.

 

[Walker]

Re: New Impeller Not Working

Muffs are only for flushing the motor, not for testing waterpumps. Run it in a barrel. You know where the waterpump is located so make sure the water level in the barrel is above the pump.

 

[gghamm]

Re: New Impeller Not Working

Ok, I have the lower unit back off and the impeller assembly apart again and a have a couple quick question as I'm putting it back together.

First, does it make a difference if I put the impeller on the drive shaft first and then spin it into the impeller cup/housing, or should I have it positioned in the cup and put them on the driveshaft tigether. I can tell either way when I have the key in the impeller, so either way works for me, just wondering which is better?

Second, I feel like the pictures I've seen and what I read in the repair manual are not the same regarding the direction of the impeller. It is my understanding that if I am holding the impeller housing in my hand and loiking in it at the impeller, the fins of the impeller should be pointing in a clockwise direction. This is how the old one came out, and how the picture inmy book looks. Is this correct, or is that just how they look when they've gone bad?

 

[hunt-fish.com]

Re: New Impeller Not Working

For my motor the OMC manual says to put the impeller in the cup prior to putting it in the housing. Wipe a little oil in the cup and insert the impeller turning it counter clockwise so the fins will point to your right or clockwise when it's in. Make sure the notch where the drive cam goes in facing you. As far as the drive cam goes, I put a little dab of grease on the flat part of the drive shaft. Put the sharp edge of the drive cam in the direction the driveshaft turns. Look at the keyway on the impeller you should be able to tell the proper direction. For me, I put the lower unit in gear and turn the prop to line up the drive cam on the drive shaft to the keyway on the impeller. Then slide the assembly on. You'll need to shift the lower unit back in to the position it was when you took it off to get the shift linkage to line up.

Good luck,
John

 

[tashasdaddy]

Re: New Impeller Not Working

take a water hose and put i to the water tube and see if you get flow from pee hole, you can also remove thermostat and check with hose to water tube you may have blockage.

 

[Silvertip]

Re: New Impeller Not Working

You probably identified the problem. The drive shaft (viewed from the top) rotates in a clockwise direction. When everything is installed the impeller will also turn clockwise which means the vanes on the impeller should fold to the left, not the right. Some will say the vanes will flip into the correct position with the engine running but there is no guarantee that will happen. Just assemble it correctly to begin with. Another way to figure this is hold the impeller flat in your left hand. Hold the tip of any vane and then attempt to rotate the impeller clockwise. This rotation forces the vane to curve left. That's the way it needs to be positioned when running.

 

[rickdb1boat]

Re: New Impeller Not Working

http://www.meegsonline.com/tmd/waterpump.wmv ] Waterpump Video that may help [/url]

 

[Silvertip]

Re: New Impeller Not Working

Just another thought -- are you sure you have the correct impeller?

 

[gghamm]

Re: New Impeller Not Working

My motor has 2 water tubes (its an 1971 85 HP with Electric Shift), I put the hose on the starboard side one and water comes out the tell tale (pee hole), on the port side water tube, it doens't seem to get the same effect.

Thanks for that video link, what that guy was doing is what I was trying.

I'll recheck that its the correct impeller when I get home from work. It seems like I've deen doing everything the say the book told me and the way people here are saying to do it, so I really don't get why its not working. I'll see what I can accomplish tonight...

 

[Silvertip]

Re: New Impeller Not Working

Compare the new impeller very carefully with the old one. Especially check for height or thickness. While it may appear you have the right one, if it is even marginally thinner it won't pump an ounce.

 

[gghamm]

Re: New Impeller Not Working

Well now I feel like a complete moron. I checked the new impeller next to an old one last night and all the fins were the same length and the holes all lined up. I was gonna put it together tonight and decided to compare the new and the old again and realized the new one was a 1/4 inch shorter than the old one. Time to go back to the dealer and try and get the right one. Thank you all for your help and suggestions.

 

[wilde1j]

Re: New Impeller Not Working

While you're at it, why not replace with a complete kit, not just the impeller? The cup and wear plate, if worn or grooved, will not give very good pumping. The stuff is just too cheap to not do it right.

 

[JasonF]

Re: New Impeller Not Working

I have a 74 50 horse Johnson that will not suck water with the muffs on but if I stick it in a barrel it pumps fine. So maybe Walker is on to something.

 

[tabbott]

Re: New Impeller Not Working

I just bought an impeller kit for a 48 hp for 70.00. Good insurance in my opinion.