what is the best way to check waterpump

[mcdonkey37]

I had an overheating problem with the top 2 cylinders. I want to make sure that water is circulating through the block and getting to the top cylinders. The motor is a 1973 evinrude 135 hp.
To my knowledge so far, there is no pee-hole by the exhaust and the water exits down by the prop. If it is hooked to muffs, then the garden hose is pushing the water through, and in the river you cant see it exit by the prop.
So, what is the best way to check that the water flow and pump is working properly?


thanks

 

[ezeke]

Re: what is the best way to check waterpump

You can add a tell-tale for about $20.00 in parts, but it will not tell you if water is circulating through the engine's cooling passages, just that the water pump is functional.

Since the 1973 135HP motor has only one temperature switch on one bank of cylinders, that is not much help if the other bank overheats.

The best bet is to add a temperature gauge kit or two to your setup so that you can monitor the temperature at the cylinder heads.

Otherwise, the rule of thumb, or fingers as it were, is that you should be able to place your fingers on the cylinder heads for a three count anytime that the engine is running.

See: http://forums.iboats.com/showthread.php?t=222677

 

[tashasdaddy]

Re: what is the best way to check waterpump

at the back, top of the mid section, is the exhaust relief ports, you should have water coming out of there, at least a mist, this is your tale tell if in question, change the impeller, and thermostats.

read this > http://forums.iboats.com/showthread.php?t=222677

 

[ezeke]

Re: what is the best way to check waterpump

As an owner of the same motor, I can tell you that the exhaust relief will and should spit water all of the time the engine is running and that it will indicate that the waterpump is functioning, but not how well.

The water flow from the exhaust relief should increase with RPM and as the thermostat opens and closes.

Since your motor only has one thermostat, you can never rely completely on a tell-tale or the exhaust relief because either will still show water even if one bank of cylinders has blocked water passages.

 

[mcdonkey37]

Re: what is the best way to check waterpump

thanks for the great information, I will add a tell tale. Are there any old posts on how to add temp gauges to older models like the 1973 evinrude 135 hp ?



thanks

 

[ezeke]

Re: what is the best way to check waterpump

Use the Z bracket and sender that comes with the outboard temperature gauge kit. Be careful if ordering on-line that you get the kit and not just the gauge; the sender has to match the guage and you will need the wire that comes with the kit to run the needed extra line.

Here's a link to a Teleflex pdf that will help: http://www.downloadingfiles.co.uk/teleflexfiles/gauges/Outboards.pdf