Carver Owners Forum

Ok, so I have now owned my 350 mariner for 2 years... last year was my first full season on the Great Lakes and LOVE the boat. Last season I never got to use my Gen as the ball valve on the through hull that was busted in the OFF position. Bummer!! But.. over the winter I did:

* New spark plugs
* New Impeller
* New Impeller coupling
* Oil Filter (did not change oil as I could not warm up the engine, figured I'd do that this year.)
* New Ball Valve, of course.

This year, fired it up and she purred like a kitten... then after about 20 mins shut down. I ASSUME it's overheating, so go to replace the thermostat. Only to find the thermostat is missing the guts! like the top 1/2 is there, but the spring and everything behind is ... well, not there! I have noticed that my reservoir is over full, could that be indication of a blockage??

So now my questions are:

1) Did the previous owner take the guts out?? Ya know, just to not have to worry about overheating issues... Doesn't SEEM like something anyone would do, BUT... Ya never know.
2) if NO, on #1, where could the parts have gone? I used a flexible claw to feel around the entire top manifold and did not find anything.
3) have removed most all hoses and did not find any signs of the parts.
4) Can I just flush the Gen and see if I have flow with no blockage? where would I hook up?

And lastly...

5) if YES, on #1, I can toss in a new thermostat, flush the system BUT...what is causing it to shut down?

Does anyone have any experience with these bad boys? Would love some guidance, as I'm grasping at straws.

I can't really say what is causing the shut down as there can be a number of reasons.....but I can say I have removed thermostat guts and left the ring in place to act as a flow restrictor to get better cooling heat transfer with no thermostat in place in cars.....so I guess I am saying No1 is a possible yes.
Do the edges look like they corroded away or cut ? Have you used the genny since you have owned the boat ?

Get your ir temp gun and check around.

Gutless thermostat would cause an over heating issue because the coolant is flowing full speed through the cooling exchanger and not slowing down to give the coolant time to transfer the heat from the coolant. I would also think about giving the system that sat for year of no use a RydLyme treatment to open up the passages in the exchangers. Those thermostat missing parts would be my guess someone removed them.

You all are making me feel much better! Parts floating around my Gen's cooling system does not seem like a good thing to me.

Bud 37 -
"Have you used the Gen since you owned the boat" - That answer would be no, During the survey, we ran it and it took a load just fine, then we shut it down. In hind sight, it never ran for more than 5 mins and she seems to run for about 10 or so before it shuts down.

Do the edges look like they corroded away or cut ? - I have included pictures (hopefully)

MKJ1040 - what is a "RydLyme treatment"? I have never done one of those?

Hard to tell, but that looks intentional. I would put a new one in.
When its running, how is the water flow out the exhaust? It should have a pretty good flow, about like a garden hose.

water flow seems pretty strong... comes out in consistent blobs of water with a steady smaller stream that is continuous. Because last year I had no water, I cannot compare anything, but the impeller and coupler is new as well as the strainer is clean. I'm hopeful that the seawater feed is in good shape.

650Guy wrote:Source of the post water flow seems pretty strong... comes out in consistent blobs of water with a steady smaller stream that is continuous. Because last year I had no water, I cannot compare anything, but the impeller and coupler is new as well as the strainer is clean. I'm hopeful that the seawater feed is in good shape.

Regarding your pics...that is how you do it....center out and the ring slows the water down..

I have the same genny and that is just how the exhaust flow is on our boat due to the muffler system they used.

I agree, put a good thermostat back and watch it closely...

Not sure what model you have, but I had an exhaust temp sensor on mine that would open up after about 20 minutes of run time. Ended up being a cracked sensor, not an over heating issue.

Thanks Bud37! So would you keep it that way? reinstall the top only? if I do that, I refill the fluid I lost, and start looking for another reason it wont stay on.

I have the 7.3 ECD. An exhaust temp sensor? I know where the exhaust runs but will look up that part. Any idea of how you narrowed it down to that?