OMC runs hot only in water

[bcobra]

Is the stern drive soley responsible for getting water to engine? i have replaced upper stern drive and stern drive water pump, water circulates fine with ear muffs on but to drop stern drive in water will not pick up on its on .I have replaced risers all hoses and flushed out the whole system. Should I replace engine water pump even though it seems to circulating. IM STUMPED

 

[HPTGreyGhost]

Re: OMC runs hot only in water

You probably have a raw water pump which has an impeller in it. You've probably burnt up the impeller. The hose provides enough pressure to move the water upwards, but the sea does not.

You can find it by looking at your belt driven components. It will have a hose coming in from your outdrive and a hose leading to the engines water pump. The engines water pump is probably fine. You should be able to pull it off, remove a couple bolts and replace the impeller.

 

[Bifflefan]

Re: OMC runs hot only in water

post your engine and drive info.
This should help in the diagnosis.

 

[HT32BSX115]

Re: OMC runs hot only in water

Should I replace engine water pump even though it seems to circulating.

It doesn't "seem" to me to be "circulating"!

That pump doesn't circulate water anyway. It draws it up from the lake and pumps it to the engine.

Some of the water goes into the engine (through the T-stat). Most of it bypasses th engine and goes into the exhaust manifolds and out though the risers.

If you're not pumping water sufficiently, you'll also overheat all the rubber parts in the exhaust system.


We need more information though. Just telling us it's an "OMC" doesn't tell us anything.


Regards,


Rick

 

[bcobra]

Re: OMC runs hot only in water

sorry it is a gm-350 engine, runs great

 

[bcobra]

Re: OMC runs hot only in water

thanks for the reply sorry for my lack of info. it is a four winns 1989 200 horizon with 350 gm engine with omc cobra outdrive.

 

[Dakota47]

Re: OMC runs hot only in water

Replace the Impeller with a complete Kit. housing and all (e-bay has them for $40.00). its a 15 minute job on a OMC Cobra (real easy). do a google on replacing the impeller on the omc cobra.

 

[bcobra]

Re: OMC runs hot only in water

ive relaced everything but engine water pump,still wont draw water 2 engine .standard cooling by the way,should i check in to adding an inline pump.THANKS 4 ALL REPLYS:

 

[a70eliminator]

Re: OMC runs hot only in water

There is a small tube off the impeller housing, it's there to let the air out of the impeller housing when drive is submerged, if it is plugged up or kinked it won't let the air out sorta like putting a straw in a glass of water with your finger over the end, it's a longshot but that's what the tube is there for.
Also the power steering oil cooler is the first thing the raw water goes through therefore the first thing that gets plugged up, but if that was the case you would have a problem on the hose too, let us know what you find.