Backwards impeller

[madbassist42]

Hi there!
Does anybody know what the symptoms are of a backwards installed impeller?
Anybody know of a video that shows it?
I would assume that no water would pump, and the motor would overheat, but is there anything else that is visual? (Other than opening up the unit and checking)
I've searched google for hours and come up with nothing.
Thanks!

 

[Lyle29464]

Re: Backwards impeller

help to know what your working on. Did you install an old impeller with a set in it?
If you installed a new one they are not directional.

 

[jimbo_jwc]

Re: Backwards impeller

I might be wrong but if installed bent in wrong direction the friction of the rubber to housing should be sufficient to reset to direction the motor runs ???

From older post from tashasdaddy Re: Impeller could be installed backwards
99% of the time they will corrrect themselves, if installed backwards.

 

[Bob_VT]

Re: Backwards impeller

Yes since they run in a concentric with the shaft and the water pump housing is slightly offset they will self correct. Over time they do pick up shape memory.

 

[Frank Acampora]

Re: Backwards impeller

The only problem is if they get stiff with age, or have slight cracks in them, there is a possibility of breaking off one or a couple of vanes. Then, the engine overheats either due to lack of pumped water or broken vanes stuck in water passages.

If you remove an impeller with a couple of years on it, it is way better to spend the 20 or 30 bucks to replace it with new.

 

[madbassist42]

Re: Backwards impeller

Okay,
Thanks very much!
It was a new impeller so I should be good to go.

Thanks!

 

[jspriddy]

Re: Backwards impeller

I might be wrong but if installed bent in wrong direction the friction of the rubber to housing should be sufficient to reset to direction the motor runs ???

From older post from tashasdaddy Re: Impeller could be installed backwards
99% of the time they will corrrect themselves, if installed backwards.

Years ago, I had a 5 (5.5?) Johnson. I was doing some lower end work and decided to replace the water pump. I went to a shop run by an old man in his backyard. When I asked for a pump, he said he didn't have one but all I needed to do was turn the old one backwards. I took him at his word.

Days later, or maybe a few weeks, I went back by for something else. He told me he ordered and got in the new pump. I told him I'd put the old one in backwards. I'll never forget what he said: "Hell, fella, you shouldn't done that".

I bought the pump anyway and the other part and left, not mad, but tickled to death. By the way, the old one worked fine.

John

 

[Sea Rider]

Re: Backwards impeller

If you like to play mechanic man you could reverse impeller each 100/150 worked hours, could take advantage to polish internal water pump to wipe small/tiny scratches, impeller will last longer and pump furiously. All impeller brands are not reversible, the ones with straight key cut are completely reversible. Must add that there are impellers and king impellers, the ones that are very flexible which remains flexible compared to more rigid ones that stays rounded once removed from w.pump.

In any case if reversing do it with a fresh top condition impeller, not and old rounded one. I do reverse mine each 150 metered hours under constat engine use, it's going for it's fourth turn (600 metered hours) and still peeing like a teenager. I know, impellers are cheap if doing the work for yourself, definitely not that cheap to reverse or change for new at a boat shop which will charge $$$ same for both works. Doing so have forgotten years back all about manufacturers water pump change intervals at max recommended N? of hours.

Happy Boating

 

[Faztbullet]

Re: Backwards impeller

A impeller should never be reversed no matter how good of condition its in.

 

[boat1010]

Re: Backwards impeller

I might be wrong but if installed bent in wrong direction the friction of the rubber to housing should be sufficient to reset to direction the motor runs ???

From older post from tashasdaddy Re: Impeller could be installed backwards
99% of the time they will corrrect themselves, if installed backwards.

This was always my thoughts too. If the water pump isn't working you will know that in very short order.

 

[jspriddy]

Re: Backwards impeller

If you like to play mechanic man... so have forgotten years back all about water pump change intervals at certain recommended N? of hours. Happy Boating

Well, I did it because it was the only way I could get back on the river that day without driving 100 or so miles. It worked fine. I never did use the new one because it was never needed.

If it hadn't worked, all I'd lost was a little time anyway. Yankees aren't the only ones with ingenuity.

I just told the story because I thought the old man was funny.

John

 

[Sea Rider]

Re: Backwards impeller

The issue with water pumps is that nobody does maintenance to them, just corrective maintenance each 2-3 years or when engine is overheating severely. Nobody is saying you should perform pump maintenence to all HP outboard motors, up tp 50 HP will be apropriate for easy LU removal and low weight. You could reverse impeller if out of stock, and only if found in good shape to pump properly. Or would preffer a grounded boat ?

Happy Boating

 

[99FisherDT150]

The idea of installing a water pump impeller backwards and it will self-correct all sounds fine. I might have installed a new impeller backwards on my Suzuki DT150S because I'm getting a weak telltale stream of hot water and the engine is overheating with alarms sounding off. So, while the impeller is self-correcting and you don't know when that will happen, do you really want to risk damage to your engine while waiting for the impeller to correct itself? Unless someone can tell me how long will it take for the impeller to self correct before damaging my motor then I might take the risk of this advice.

 

[racerone]

Drop the lower unit and install impeller for correct rotation.----Not hard to do.-----How did the old impeller look ??

 

[99FisherDT150]

Drop the lower unit and install impeller for correct rotation.----Not hard to do.-----How did the old impeller look ??

Might have to do as you suggested and I can verify that a clockwise turn of the drive shaft while installing the housing over the impeller is the correct procedure. Otherwise, I will have to do as you suggested.
Note: For an old engine ( 1996 Suzuki DT150S) which I believed the lower unit was never taken off since originally built. The old impeller as far as I could tell looked pretty good, no cracks, no broken blades, and is twisted. I did replace the bottom plate and greased it, greased the impeller blades and greased the pump housing as well, and replaced pump shaft seal. However, the new impeller blades did look longer than the old impeller. I figured they will bend to fit inside the pump housing once installed. When I reinstalled everything, including the keyway to impeller, I pressed down on the pump housing while turning the shaft clockwise. Prior to placing housing over impeller, I made sure the impeller rotated with the shaft. From all I read and watched on Youtube about lower unit and impeller replacement showed turning shaft clockwise upon installation of new impeller. If you know something about Suzuki DT150S , appreciate your thoughts. Nevertheless, thanks for your response.

 

[racerone]

It should be correct as is.