Carver Owners Forum

Thanks Roxanne for sharing your experience. i discussed with my mechanic yesterday and he was planning to contact Mercruiser. This information will be very helpful. Thanks very much CY User Forum.

There was a check valve kit that you can install before the cooler to prevent the water from flowing back. Black rubber or plastic ball typically at back port side of engine. If you have or install this valve, you have to be aware of it's presence when it comes time to winterize. Many currently in circulation are probably not working anymore because of the way the engine was winterized.

I installed check valves on the exhaust line to prevent the water from flowing back. Seems to have solved the issue. I had gasoline with 10% ethanol which I believe was a contributing factor. Ruining non-oxygenated gasoline and exhaust check valves seems to have resolved this issue.

Thanks Roxanne and CYO Forum

One season later without any issues. Check valves solved the problem.