V6 driven OMC overheats at high speed

notevipr

Cadet
Joined
Jul 3, 2009
Messages
6
My friend has a V6 driving an OMC and at high speed she overheats. Drop back below 2500 rpms and she cools down fast. It has a new engine put in last season and has done this ever since.
Thanks for your help.
 

Bondo

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Apr 17, 2002
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71,082
Re: V6 driven OMC overheats at high speed

It has a new engine put in last season and has done this ever since.

Ayuh,... What about the Raw waterpump Impeller,..??..??
 

notevipr

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Jul 3, 2009
Messages
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Re: V6 driven OMC overheats at high speed

We blew a drive gear after the motor swap and put in a new impeller while we had it apart.
 

gadget73

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Jun 20, 2009
Messages
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Re: V6 driven OMC overheats at high speed

I wonder if you don't have old impeller bits stuck in a cooler. Unhook the hose at the top of the transom assembly, and unhook the seawater feed at the thermostat neck. Run a garden hose through the thermostat end and see if any chunks flush out the other side.
 

notevipr

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Jul 3, 2009
Messages
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Re: V6 driven OMC overheats at high speed

Thought that it might be some restriction like that. Thanks for telling me how to flush it out. He's out fishing now so we'll try that as soon as we can.
If any one else has any other suggestions please post them.
Thanks again
 

a70eliminator

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Sep 9, 2007
Messages
3,762
Re: V6 driven OMC overheats at high speed

Raw water inlet hose, the one that goes from the pivot housing to the transom, ok unril the boat comes on plane and the hose comes out of the water, a wild guess if all the basics check out.
 
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