[karmann]

Hello All.

When I bought my 272 Z barchetta, On the try out run from the dealer the motor overheated and the alarm went off. He assured us it was minor and that they had just put on a new sea pump. After a price reduction we purchased the boat. We got it back home and had a marine mechanic work on it, The thermostat was STUCK closed, Also, the cooling system had pieces of rubber trapped in it, he cleaned them out by disconnecting all the hoses and using compressed air. Also he did confirm the new sea pump. He ran the boat at a high RPM for 15 min on the hose and the temp would not exceed 150 degrees, Checked with a infared thermo. all seems fine, I've yet to give it a test run due to some other issues,
My question is this, I ran the boat again with the hose attached and it cooled fine, However I did notice that at 2500 rpm the large hose from the thermostat hsg down the the front water pump was collapasing. Any input on this issue?
Is it because the thermostat was not open all the way, causing suction?
thanks

[WetWilly]

Hi karmann,

The thermostat could have been could have been the culprit, you didn't say if the motor was completely up to operating temp or not. Another possibility is the hose itself, how old is it and does it feel soft or spongy when squeezed? If your not sure of it's condition, see if you can find another hose and compare them.

The only other things I can think of is, there may still be some old debris causing enough blockage before the hose but not enough to over heat at your test speeds or was it possible you didn't have faucet turned on enough to sustain the water flow at that RPM?

WetWilly

[300sflyer]

If I'm not mistaken, that hose should have a coiled wire inside it, to prevent it from collapsing. Not sure what engine you have, but my 5.7 has one.

Hope that helps.

[karmann]

Hello All
Even with my dislocated arm, I finally got to try out my 95 272 Z barchetta.
It's still overheating????
It overheated when we bought it, the marine co said it was probally a stuck thermostat, or rubber pieces of old impeller. When we got it home we had a mechanic work on it, The thermostat was stuck , and he found pieces of rubber in the water system. After all that it cooled great on the hose running at a high rpm, it would not exceed 150 degrees. Now when in the river, it ran good for about 4 to 6 min at 4000 rpm, then the temp gage slowly increased from 150 to 200 degrees, and the alarm goes off at 200 degrees. if you stop, and idle it cools back down and the alarm goes quiet. If you idle around at 1500 rpms it ok, if you try a little higher it starts to go up then when it reaches 200 degrees the alarm sounds???
Any advice? I called the mech and he said the rubber baffles in the exhaust manifold are probally bad?
I don't know where to start.
thanks in advance for any help..

[SEMIJim]

Are you certain the impeller is good? On the hose you'd have water pressure aiding flow. In the water, it'd be all up to the water pump. Check this out: Problem with non-OEM water pump impellers.

Good luck,
Jim

[jasfiveo]

Just had this same problem. Opened up the sea pump and the impeller was shredded. The boat overheated and the exhaust shutters melted because of the hot water trapped while the motor was turned off. If your shutters are bad you will know because you will get water lock and it won't start. I replaced the exhaust shutters, impeller, and thermostat and it ran great on the lake last week. Check the impeller again. Water hose is not a good test because the pressure and the water temp is cool.

[karmann]

Hello All
I forgot to mention my shifter stuck in forward.
Today , the mechanic found that the large hose that is collapsing more and more at higher rpm, is supposed to have a wire in it.
Also, the shifter cable was not installed right and the drive shaft tore it up.
We took the exhaust madifold off and there was no blockage.
I'm hoping that the problem is just a bad hose.
thanks

[karmann]

UPDATE
As I write , the mechanic has the lower unit off.
Problems due to previous mickey / mouse mech.

1. Intake hose through lower unit kinked almost shut.
2. shifter cable installed wrong, got caught in drive shaft.
3. Excessive sealant used on seals. bellows, ect.
4.exhaust butterflys broke, ( no parts in system).

And to think, I thought I got a good deal?????????

Thanks to all responders

[karmann]

Hello All Again

Is it ok to mention the marine store's name I bought my boat from, and warn others to be cautious if they do business there, Or is that a NO NO ?

Somebody did a lot of shoddy work on this boat.
thanks

[SEMIJim]

Originally Posted by karmann

Somebody did a lot of shoddy work on this boat.

And therein lies the problem: You don't really know who did the shoddy work.

Jim