lakenormangal
Seaman
- Joined
- Sep 6, 2014
- Messages
- 66
I have a 1990 Sunbird with an OMC Cobra 4.3 HO.
Changed the alternator and fired up the boat with the muffs on it and everything seemed fine. Temp was normal.
Got it out on the lake the other day and it overheated very quickly. I probably shouldn't have taken it out on a such a busy day, there were boats everywhere, and I was so busy watching out for all the other boats ( it was nuts, one guy in a canoe ran into a fishing boat ( that was standing still) near me and then almost hit me. I was slowly trying to get away from all the other boats.
So it took me a few minutes to recheck the gauges, I had checked them at the landing. The temp gauge was almost all the way over in the red. So I shut it down. a few moments later, I heard something pop in the outdrive. ( think it was the impeller housing, the back popped off.)
I actually swam back to the dock towing the boat most of the way til I could get a tow. Turned the motor off 1500 ft from the landing.
Once we got it back home, I checked the impeller. Its pretty beat up and a little deformed looking. But the all the "flappers"were in place and the impeller is not stuck or melted to the liner. We checked the movement of the water pump shafter and it moves when you bump the motor with the key.
We think the thermostat stuck closed, I’ll know tomorrow morning when I check it. ( Boil it in water with a temp gauge and see where or if it opens.)
We pulled the plugs and water came out, so both head gaskets are blown. The motor moves freely, so the pistons and cylinders are probaly fine. The boat is going to my friend's shop later today and he's pulling the heads and changineng the head gaskets.
Here's my question, I have ordered a new impeller, impeller housing, gasket and liner. My friend with the shop tells me that those parts are probably all that is needed, BUT I looked looked at the breakdown page of the cooling system in the OMC manual and there’s lots of stuff that could be affected by the heat. I know there’s someone here this happened to. What else do I need to check? What other parts might be affected? I mean it got hot enough for the back of the impeller housing to melt and pop off.
Now the other question, I did notice was this black crud build up around the impeller in the impeller housing, it seems to be from the impeller turning in the liner, while the impeller was super hot. And it seems to be localized a a corner of the impeller housing, BUT there is a little bit of tiny black crumbles that I noticed on the wall of the one of the passages. Could that have clogged up any small passages?
Thanks.
Changed the alternator and fired up the boat with the muffs on it and everything seemed fine. Temp was normal.
Got it out on the lake the other day and it overheated very quickly. I probably shouldn't have taken it out on a such a busy day, there were boats everywhere, and I was so busy watching out for all the other boats ( it was nuts, one guy in a canoe ran into a fishing boat ( that was standing still) near me and then almost hit me. I was slowly trying to get away from all the other boats.
So it took me a few minutes to recheck the gauges, I had checked them at the landing. The temp gauge was almost all the way over in the red. So I shut it down. a few moments later, I heard something pop in the outdrive. ( think it was the impeller housing, the back popped off.)
I actually swam back to the dock towing the boat most of the way til I could get a tow. Turned the motor off 1500 ft from the landing.
Once we got it back home, I checked the impeller. Its pretty beat up and a little deformed looking. But the all the "flappers"were in place and the impeller is not stuck or melted to the liner. We checked the movement of the water pump shafter and it moves when you bump the motor with the key.
We think the thermostat stuck closed, I’ll know tomorrow morning when I check it. ( Boil it in water with a temp gauge and see where or if it opens.)
We pulled the plugs and water came out, so both head gaskets are blown. The motor moves freely, so the pistons and cylinders are probaly fine. The boat is going to my friend's shop later today and he's pulling the heads and changineng the head gaskets.
Here's my question, I have ordered a new impeller, impeller housing, gasket and liner. My friend with the shop tells me that those parts are probably all that is needed, BUT I looked looked at the breakdown page of the cooling system in the OMC manual and there’s lots of stuff that could be affected by the heat. I know there’s someone here this happened to. What else do I need to check? What other parts might be affected? I mean it got hot enough for the back of the impeller housing to melt and pop off.
Now the other question, I did notice was this black crud build up around the impeller in the impeller housing, it seems to be from the impeller turning in the liner, while the impeller was super hot. And it seems to be localized a a corner of the impeller housing, BUT there is a little bit of tiny black crumbles that I noticed on the wall of the one of the passages. Could that have clogged up any small passages?
Thanks.
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