OMC Cobra 4.3 impeller/pump questions

[Robar]

Hello. Just started up the boat to get ready for summer. Only used it twice last fall after buying it and putting it away.<br /><br />Attached an engine flush attachment, started it up and idled for a minute, then smelled the impeller frying. No engine heat yet though. I took the pump cover off and confirmed the impeller is cooked, but wonder why - everything was fine when I parked it. No winter freezes etc. <br /><br />The flusher squirts water out around the water inlets, and only fills the lower unit if you apply pressure to it to seal it. Should the impeller draw enough water up when using a flusher, or does the hose need to fill the lower unit for the impeller to work? I am hoping that it is just the impeller and not the pump....I think I read somewhere that the pump is a major ordeal.<br /><br />Any insight appreaciated.<br /><br />TIA,<br />Robar

 

[cobra 3.0]

Re: OMC Cobra 4.3 impeller/pump questions

What do you call a flusher? It needs to be muffs off a garden hose. It should easily supply your impeller. If not something is blocked.<br /><br /><br />Something like this:<br /><br /> http://www.iboats.com/mall/index.cg...&current_category=muff&submit.x=54&submit.y=5

 

[Robar]

Re: OMC Cobra 4.3 impeller/pump questions

I have "muffs" - but the water does not get up to the impeller without applying pressure to them to prevent leaking around the "muffs". <br /><br />My question is - should the impeller draw the water up when using muffs? <br /><br />Whats an easy way to check the pump itself?<br /><br />Thanks,<br />Robar

 

[vinney]

Re: OMC Cobra 4.3 impeller/pump questions

If the vent tube is blocked. The tube on the water pump housing. If the hose is blocked You will fry the water pump impeller. If the housing is melted you need to change the housing,insert,impeller. Make sure the vent tube is clear. Make sure the muffs are tight on your drive Squeeze them together.

 

[Robar]

Re: OMC Cobra 4.3 impeller/pump questions

Thanks, I ordered all the parts - it did fry the housing too. I think I'll put a clamp on the stupid muffs next time.<br /><br />Does the circulated water exit thru the prop, or elsewhere? I'm new to OMC, and haven't got the manual yet.<br /><br />Thanks.

 

[pra100]

Re: OMC Cobra 4.3 impeller/pump questions

I have a 4.3 cobra and mine exits thru the prop and thru the bottom of exhaust bellows.Mine has slits in exhust bellows on the bottom side.I don't ever open the garden hose valve wide open as I read that it puts to much pressure on the pump.

 

[Robar]

Re: OMC Cobra 4.3 impeller/pump questions

Thanks Philip. Do you wait until water is flowing from the exhaust/prop before firing the motor, or does the impeller draw the water up?

 

[pra100]

Re: OMC Cobra 4.3 impeller/pump questions

I just hook the muffs up (I use the kind that has water to both sides of drive) then I go to the faucet and turn water on.By the time I walk back to boat and climb up in it I start her up,by then it has water going everywere.You will see water coming out from under side where bellows are by then.

 

[steve n carol]

Re: OMC Cobra 4.3 impeller/pump questions

Robar, what happened when you replaced the impeller and housing??..sl