over heating 260hp omc inboard

[jawacdah]

engine over heats when run above 3000rpms only.<br />I have replaced the impeller, thermostat,checked all hoses. I have good water supply to the engine. PLEASE HELP

 

[Fouled Plug]

Re: over heating 260hp omc inboard

Could be a bad circulating pump on the engine, loose drive belt maybe. Is it fresh water cooled? The heat exchanger tubes may need to be unplugged.

 

[jawacdah]

Re: over heating 260hp omc inboard

Yes the 260 omc is fresh water cooled, and what is a heat exchanger tube? thanks for the reply I checked the belts and the drive belt that operates the power stearing is wore and sitting low in the pully, and there is belt dust on the front of the engine. thank you for your time in this matter.

 

[Fouled Plug]

Re: over heating 260hp omc inboard

Sounds like the power steering belt could be slipping when the RPM's come up. Was the water pump one shot (glazed,cracked) as well? The heat exchanger is the big cylinder the coolant hoses go into. The impeller from the lower unit circulates cold fresh water around a series of tubes inside to cool the water/anti freeze mix from the engine. Pull the cap and take a peek inside.....lots easier to understand than my description! How hot does the motor get?

 

[jawacdah]

Re: over heating 260hp omc inboard

I changed the belts and when I started up the engine I could smell burning rubber! The pully on the water pump going to the power stearing is glazed. What should I look for in the heat exchanger? The engine heats up to 240 degrees. I orded a new water pump today should have it installed by friday. thank again for you help!<br /><br /><br />E-mail floyd370@email.com

 

[Fouled Plug]

Re: over heating 260hp omc inboard

If your heat exchanger has removable end caps, you can pop them off and run a cleaning rod through them to scrub the goop out of the tubes. Kind of resembles a cleaning rod for a .22 rifle.

 

[jawacdah]

Re: over heating 260hp omc inboard

I installed a new circulating pump on the engine yesterday, and It still over heated! I also put on new belts. I will try to find a cleaning rod to clean out the exchangers. Thanks again for your help.

 

[Fouled Plug]

Re: over heating 260hp omc inboard

Also, check to see your the water pasages in your exhaust manifolds aren't plugged with scale or silt. I've had a plugged manifold cause an overheat before. Good luck, you'll figure it out!