OMC 4.3 Cobra overheating. Help.

J

Jode

Recruit
Thread starter
Joined
Jul 20, 2012
Messages
2
First trip of the season motor over heated while idling within 30 minutes.
Have tried all of the obvious trouble-shooting solutions. Changed pump housing and impeller. Installed new thermostat. Separated top and bottom drives and inspected grommets, seals and tube...all looked OK. Checked to make sure impeller shaft was turning and it was. Ran water through all inlets, ports hoses and exhaust...no blockage. Water flows fine out of inlet hose to thermostat when the muffs are used. When I put the boat in the water, the water flow through the inlet hose is sporatic or not at all. Totally baffled :( Any suggestions would be greatly appreciated.

Thanks in advance
Dwight
 
Howard Sterndrive

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
Re: OMC 4.3 Cobra overheating. Help.

water can get in, but can it get out?

corrosion in the exhaust manifolds can restrict water exiting and taking the heat out with it...
 
I

indybleck

Petty Officer 2nd Class
Joined
Sep 29, 2011
Messages
136
Re: OMC 4.3 Cobra overheating. Help.

There was a thread on here earlier some one had the same problem, check some of the past threads, you checked the grommets on the tube, is the impeller housing good? Sometimes on the muffs the water is forced through the lower instead of the impeller pumping it through.
 
J

Jode

Recruit
Thread starter
Joined
Jul 20, 2012
Messages
2
Re: OMC 4.3 Cobra overheating. Help.

Howard Sterndrive said:
water can get in, but can it get out?

corrosion in the exhaust manifolds can restrict water exiting and taking the heat out with it...
Click to expand...

I have good flow in and out. I am wondering if there could be back pressure from the motor that is restricting water flow in from the impeller?
 
You must log in or register to reply here.
Top