Grease for impeller?

[kevinwd1]

I'm about to fit a new impeller into a 4hp 1979 evinrude and was wondering if it?s a good idea to put some grease on it .I have some marine grease which I used on the wheel bearings on the trailer and was thinking of using that. Is that a bad idea?

 

[Bosunsmate]

Re: Grease for impeller?

just a thin bit so it doesnt run dry on first start up and helps install is what i do.

 

[Grub54891]

Re: Grease for impeller?

I use a small amount of cooking oil,or even crisco lard,bacon grease,whatever is handy. If I can eat it,so can the fish! Heck mabe it helps me catch fish!

 

[Georgesalmon]

Re: Grease for impeller?

I use a dab of good old vasoline just to lube it for the first few seconds of start up.

 

[racerone]

Re: Grease for impeller?

There is no need for grease at start-up.-----The pump floods with water before you pull the cord.---Water is the perfect lubricant for the impeller !!!

 

[Mohawkmtrs]

Re: Grease for impeller?

I put a Volvo-Penta water pump kit in last year and with the kit was a small packet of glycerine for lube.

I figure if it's good enough for V-P, it's good enough for me.

The wife went out to the Health Food store and got me a 4 oz. bottle of vegetable glycerine for $5.00...enough to last a lifetime.

 

[jb93]

Re: Grease for impeller?

Not all rubber products like grease. I am not sure what impellers are made out of...probably either Nitrile or Neoprene. If they are Nitrile, the oils and grease are no biggie, as Nitrile is the most common material used in oilfield seal applications. If Neoprene, then it is actually comparably poor resistance to petroleum based products (grease, oil, vaseline). If there is some incompatibility, the rubber "could" swell up to 10%.

As pointed out above, water floods the pump before start up. I do see the value in making it a little slick for installation purposes...but no positive effect for start up. I would go with a very light coat of oil on the inside of the housing so the legs of the impeller will slide in easily, but I would make sure it was Nitrile and not Neoprene.

 

[Crosbyman]

Re: Grease for impeller?

I have used synthetic grease just in case petrolium grease eats into the impeller. In any event any grease probably gets flushes out
quickly or after a few million revolutions ...

 

[racerone]

Re: Grease for impeller?

Water lubricates the impeller , no greasing is needed at all!

 

[Will Bark]

Re: Grease for impeller?

I use dish soap to aid in impeller installation; so far works fine

 

[boobie]

Re: Grease for impeller?

I've always used grease as it makes the assembly easier. It will wash out right away when started.

 

[Big Fish Billy]

Re: Grease for impeller?

I use a dab of good old vasoline just to lube it for the first few seconds of start up.

Ditto Dat...

 

[scottmm73]

Re: Grease for impeller?

Use silicone based grease or soap. As an aviation mechanic, I was always discouraged using petroleum based grease products on rubber o-rings and seals. It seems petroleum based grease will make rubber swell and break down over time. If you commonly replace your impeller annually, using petroleum based grease will probably not be a problem, anything longer than that I would not condone. Also, petroleum based grease is hydrophobic and will not dissolve upon water contact.

 

[wrmdunker]

Re: Grease for impeller?

I have used a thin film of dish soap to aid with the install. After that, I agree that water is all that is necessary for operation.

 

[SilverSS07]

Re: Grease for impeller?

The factory service manual says to use a little grease so that's what I do.

 

[14 foot Starcraft]

Re: Grease for impeller?

I always use a little silicone grease.

 

[boobie]

Re: Grease for impeller?

I agree with the service manual.

 

[HighTrim]

Re: Grease for impeller?

I myself do not see any need to grease an impeller in any way. For one reason, as stated, the pump is fully submerged and DESIGNED to be lubricated by the water.

Now, what about if you don't boat for a week, and the motor is pulled out of the water and dries. Do you pull the gearcase and regrease for initial start up? Of course not right. So why bother for the first start up.

You will start it a gazillion times after that without grease. Greasing it for one start up will make zero difference in its lifespan.

 

[nwcove]

Re: Grease for impeller?

^^ i have to agree! i install the impeller dry, into the housing, align the drive pin , and set the housing down over it. works every time. no need for "ease of installation'.

 

[boobie]

Re: Grease for impeller?

The grease just makes the assembling easier. 'Nuff said !