Major problem with 5.7

[justlakinit]

Ayuh,.... Ya rarely ever do in a boat,.... Spark plug color diagnosis is a sure-fire tool,....

So how would I go about determining that by the plugs....they all look pretty uniform.

 

[justlakinit]

Is the waterpump on the engine the correct rotation?

The motor burned up with the original water pump and a new water pump. I am not sure which way it is supposed to rotate, I just ordered one to fit my motor and it appears to work. I would think if it was the wrong one, it would get hot on the temp gauge and I would expect the motor would burn up a lot faster than one and a half seasons.

 

[achris]

I know I'm late to this party, but I have a few tricks I can show off with, so I should be welcome... (I hope)..

First question that struck me when reading the opening post.... What revs are/were you making at WOT? If the prop's too big and overloading the engine that would very easily account for your hot spots, especially between cylinders as that is where the least water can flow...

As for determining water flow and volume, there is a 'water pump output test' in one of the manuals. You can run that to determine if the pump is supplying the right amount of water. The other possibility is a 'non-constant' water flow, but given a 1996 (Gen II) drive that is less likely, but still worth checking. The way I check is to put a section of clear hose in the incoming water line (the one between the transom plate and the t-stat housing). You MUST see a solid stream of water, no bubbles....

So, revs and solid water....

Chris.......

 

[justlakinit]

I know I'm late to this party, but I have a few tricks I can show off with, so I should be welcome... (I hope)..

First question that struck me when reading the opening post.... What revs are/were you making at WOT? If the prop's too big and overloading the engine that would very easily account for your hot spots, especially between cylinders as that is where the least water can flow...

As for determining water flow and volume, there is a 'water pump output test' in one of the manuals. You can run that to determine if the pump is supplying the right amount of water. The other possibility is a 'non-constant' water flow, but given a 1996 (Gen II) drive that is less likely, but still worth checking. The way I check is to put a section of clear hose in the incoming water line (the one between the transom plate and the t-stat housing). You MUST see a solid stream of water, no bubbles....

So, revs and solid water....

Chris.......

thanks Chris for the input.
WOT it runs just under 5000 rpm, but I very seldom run it at WOT and if I do it's just for a min. or less in most cases.
I tried the clear tube trick earlier and I did not have any bubbles.....I never got to check it at WOT, our lakes are to rough to look at that speed, but it was clear up to about 4000 rpm.

 

[alldodge]

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Is you thermostat installed like in the link below, including the sleeve and gasket?
http://www.mercruiserparts.com/Show_...NUM%2FALPHA%29

Also, are you using the original engine circulating water pump?

 

[justlakinit]

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Is you thermostat installed like in the link below, including the sleeve and gasket?
http://www.mercruiserparts.com/Show_...NUM%2FALPHA%29

Also, are you using the original engine circulating water pump?

The circulation pump was replaced, and yes my thermo is installed as in the link. Hose routing is the same expect #9...water comes from stern drive thru steering cooler.