Suckin' sand

[Rickfifty]

I'm pretty sure I sucked up some sand on my last outing. No problems getting back(no overheating). I'm in fresh water so I figure it's flushed itself. 2 weeks later(now), I put the muffs on and fire it up. Reaches operating temp. and then some. I see steam so I shut it down. Pull impeller, cooked. With impeller removed I turned on the muffs but no water was reaching that area. My questions are; Does the impeller "suck" the water up to it? If muffs are pressurized should the water flow freely through the ports with impeller removed or maybe it's clogged somewhere and how could I flush out the clog? It's a 4.3 OMC Cobra 1988. Sorry this is so windy & convoluted. Thanks for any tips.

 

[Dunaruna]

Re: Suckin' sand

Raw or fresh water cooled (do you have a heatexchanger)?<br /><br />Cooked impeller: were blades missing?<br /><br />Aldo

 

[Don S]

Re: Suckin' sand

Yes you need the impeller, using the presssure from a water hose on muffs will not get water to the engine.<br />The sand really eats up impeller housings and impellers. You might want to check them out, and on a Cobra that's very easy to do.

 

[Rickfifty]

Re: Suckin' sand

No heat exchanger. I have the impeller off. No missing blades but some of it has melted through the slots in the housing. Also, with the impeller housing off I tried to flush the lower drive up to the area where the impeller goes. Nothing comes out. Clogged? If so, how would I unclog?

 

[crazy charlie]

Re: Suckin' sand

Replace the housing and impeller.The sand didnt help things but I dont think that is what melted the vanes.When you start an i/o the water must be running into the muffs already before you turn the key.Even if you just crank a motor a few times w/o water the vanes will get damaged.When you replace the water pump make sure you coat the inside of the housing with either dish detergent or marine grease .If you will be using the boat more this season you can use either.If you are putting it away for the winter ,then use grease.Not much but coat the walls entirely.Charlie

 

[eyezaiah]

Re: Suckin' sand

I have a question. should you trim the outdrive all the way down when using muffs or does it matter? What about the amount of water pressure?<br />I have a volvo AQ125A motor, would it be ok to just put the hose into the filter strainer housing? this motor appears to have closed and freshwater cooling.

 

[cmyers_uk]

Re: Suckin' sand

Charlie, My manual says to coat the impellor with grease so thats what I do , but why doesnt it just wash away on the first outing?<br /><br />Regards<br />Chris

 

[DHPMARINE]

Re: Suckin' sand

If your impeller is melted,and the pump liner is coated with black melted rubber,the pump has been run without water getting to it.I doubt an incident 2 weeks ago caused it,but who knows?<br /><br />Years ago I put 4 waterpumps into the same outdrive,all were charred.Turned out the owner only 'cranked her up to be sure she'd start' before hooking up to go to the lake.<br /><br />DHP

 

[Bondo]

Re: Suckin' sand

with the impeller housing off I tried to flush the lower drive up to the area where the impeller goes. Nothing comes out. Clogged? If so, how would I unclog?

Ayuh,<br />That's Where your problem is...........<br />I'd Start with a stout piece of Wire.... Maybe a Welding Rod........

 

[Rickfifty]

Re: Suckin' sand

Thanks Bondo, that's what I was going to try. I've never run it out of the water without muffs so that's why I thought it could be clogged. And that lead me to think of the sandy mud I had sucked up 2 weeks before.(that was the last time I had used it). Just didn't want to put new impeller(including outer housing!) without making sure water was able to get up there.