OMC king cobra
 

Anyone!! OMC KING COBRA OUTDRIVE
I keep burning up impellers, has anyone eliminated the factory impeller and switched to a crankdriven raw water pump ? If so does it work? Also is this advisable? Impellers for this outdrive are in the 230.00 range

What is the damage and how long are they lasting? Do you just replace the impeller? Do you ever just dry fire it just to make sure it fires? Does your housing have the bleed hose?

Also do you use grease to install the impeller?

I never had a problem with the impeller in a regular cobra.

If you do go to a crank driven pump you need to change the hose to a reinforced type from the transom so ut doesnt collapse under suction

I just started it up for the first time after winter. I had drained the engine of all water before winterizing then filled it up with antifreeze. Tried to start it it fired right up but with no water being sucked up into the engine after about10 seconds I shut it off pulled the impeller cover to find that it had half melted (that quick ) does this type have to be primed before starting ? Yes housing has bleed hose. No grease just some spray lube.

I've been reading on a crank pump does it have the suction power to pull from that far of a distance from lower unit to crank pump?

Also is a crank pump the best way to go?

I was talking to a guy at the boat ramp last year about impellers and he said he had a military grade impeller that the navy seals use on their high speed boats and that they will run out of water, have you heard of these ? And know where to get them ?

Check to see if Globe makes one for your application.
https://www.gcsmarine.com/

those pumps work fine, you have a problem with housing, hose etc, make sure housing is sealing and years ago had sierra impellers that were made undersize and would not work...

OMC impellers needed here

Most likely you need the whole kit - housing, cage, gaskets, impeller, wear plate

Post your model number and serial number here of the engine..

I am lost that the impeller cost 230 dollars. Who is selling you that ? Last time I checked you can but the complete kit for way under that. Most likely what you need anyways. Overheating warps the plastic housing and scares the wear plate. Side note model number and serial number needed here to make sure about your app and service bulletins.

Make sure the vent hose is not plugged.

Well I just got the new kit in the mail got it from eBay 230.00, (damn) I installed it using grease and sealer around the gasket fired it up and it spot for a couple of seconds then sounded like it grabbed then started flowing (phew) I wasn't praying for a good turn out! Also I wasn't taking any chances I removed the hose from. Thermostat cover and took the garden hose and sprayed into the engine until water came out of the vent hose, sort of liked primed it a bit. Guess I'll take the whole pump out every winter lol, if it saves me 230.00 bucks I'm doing it !
Thanks for all the help guys!

Oh for all that wants to know the outdrive is called ( the daddy cobra ) or something like that ! That's why the impeller was so expensive the other two OMC cobras price for impeller was way less expensive

I was almost sure that it needed the complete kit - thanks for the reply back on the fix.

The daddy cobra was still the king cobra - and that kit last time I looked it up was way less 230. That was about 2 years ago. just saying

Using grease is a no no. The impeller is adversely affected by petroleum products. The thing to use is liquid dish soap. Once the o-ring is bellows cemented to the housing you should need nothing on the sealing area. Did you make sure the vent hose was clear? The little one on the pump housing.

Oh mannn ! So you think I should take it back apart and clean off all grease then reassemble?

No. The thing with grease is it breaks down the material the impeller is made of. You most likely ran most if the grease out. I grew up using grease as a kid, Mercruiser school recommended dish liquid.

Wow !!! Thanks for the tip! I guess it makes sense soap will wash right away!! Lol

Ky jelly water base.

Volvo Penta and Indmar and the makers of impellers (Johnson) all recommend Glycerin - You can buy it at drug stores or the same with the water base Ky

You are fine so far as your ran the boat and hopefully washed out the grease.

Next time just do not use any oil / grease products

Another good idea !! Thanks

I also just bought an ebay $230 kit for a king cobra and the bottom hole does not even line up. I just found this one for much cheaper. I have a spare outdrive too and both had a different part number but lined up the same as far as bolt holes but the vent hose was on the other side. (986272 and 984744). Only $46 shipped
http://www.go2marine.com/product/158...4-18-3348.html

For $230.00 , It should have come with a LARGE TUBE of KY Jelly......