Good Or Bad Idea??

[DockedPay]

Hello all. I have another thread going about an overheating issue I have with my port side motor. FYI, I have twin 1988 5.7l mercs with alpha drives. I have read and been given some advise to diagnose the problem. In order to eliminate or confirm the problem is at the outdrive end (ie: impeller) I have a thought.....If I got some hose and made necessary extentions, coupling, etc -I would connect the water intake line from my port motor (at thermostat) and connect IT to my starboard thermostat housing. I would then re-route my starboard water intake line to be connected to the port motor side. My theory is that if I then ran both motors, the cooling water to each motor would be supplied by the opposite drive / impellar. If my problem is in the drive, I would then expect my starboard motor to now overheat and my port motor to run fine. If my problem continues to be the port motor then I would KNOW its not being caused by the outdrive / impeller and that it is definitely in the engine. YOU follow??? Please,.. tell me your thoughts! Will this work?..can I cause any damage?..Good or Bad idea?..(fresh water cooled boat by the way)......THANKS!

 

[hullofalottatrouble]

Re: Good Or Bad Idea??

read your other post.. sounds like the impeller is new? and the mechanic showed you had water from drive? if you were there and they proved it to you in person I would move on to looking into something else and not focus on impeller anymore.. was old impeller all torn up? Get all the missing pieces? therm working? etc..

 

[thumpar]

Re: Good Or Bad Idea??

There are alot of easy and free diags you can do that will tell you what is causing the issue too.

 

[HT32BSX115]

Re: Good Or Bad Idea??

Howdy,

If you have an overheat problem and you have not replaced the impeller in more than a couple of years or you suspect the impeller (because you may have run it dry etc) you should start there first.

Those impellers are pretty sensitive to damage if run dry for even a several seconds.....If it's been in there more than a couple of years (and there's an overheat problem) I would replace them anyway.

You could swap the raw water supply hoses. but if the raw pump is bad you should replace both of them.

Instead of swapping the hoses I would disconnect them and just run each engine and see if each pump will shoot out about the same flow of water. Hook a piece of hose to the hose you disconnect from the back and hold it overboard and run each engine at idle (just for 30 sec or so) and see what each pump puts out.

If they pump a lot of water than you may have a blockage.....like a previous pump failure that put pump fragments up into the oil cooler.


Regards,


Rick

 

[DockedPay]

Re: Good Or Bad Idea??

UPDATE!...see "my first thread...merc overheating"....good tip (I think)

 

[wil7483]

Re: Good Or Bad Idea??

Instead of trying to "McGyver" it, why not take it in to be serviced if you can't figure out the problem.