1975 70hp 70573-b Evinrude revival

[Nandy]

I took time today to work on that motor I bought. It is a 1975 70hp 70573-b Evinrude. When I bought the motor/trailer/boat combo all I did was check for spark. The previous owner took the top carb out about 13 years ago or so and the boat has not been used since as the gentleman passed away.
I put that carb back, made an impromptu throttle link as the original one was lost as well as the carb nuts. I lubricated the motor with a bit of fuel mix via the sparkplugs and gave it a few turns, then shoot a bit of mix from the carbs, put the plugs but not the ignition cables, a few revolutions and I was ready for a real start. I connected to the gas connector and prime the bulb. It got hard real quick, the motor started but died real quick. A mud dabber had put a nest in the motor gas connector. I connected the gas straight to the pump filter and will clean that connector later.
The motor started real quick but I could not see the tattle tale stream of water. Shut it down real quick and went checking to make sure another mud dabber had made a nest. Well guest what, there is no tattle tale port. I felt a little stupid, now this take me to my next point.
I really want to have a way to tell that the water pump is not working other than the overheat buzzer going off. I have read about the possibility of making a hole into the water jacket and making your own tattle tale port. Or even installing a water preasure gauge. Anyone here has experience with that procedure for this motor? Also, how do I test that overheat sensor, is that thermostat sensor normally grounded or normally open?

Thanks!

 

[iwombat]

Re: 1975 70hp 70573-b Evinrude revival

check out the sticky post at the top of the thread list - adding a tell tale.

 

[tashasdaddy]

Re: 1975 70hp 70573-b Evinrude revival

the tale tell on that motor is the 2 exhaust relief ports on the back of the mid section, you will get droplets or a mist. do a compression check, clean the carbsand brebuild, and service the water pump with a water pump kit. not just the impeller. suggest getting an OEM manual, outboardbooks.com or ebay.

 

[Nandy]

Re: 1975 70hp 70573-b Evinrude revival

iwombat, that is a great article. Now that i remember, that was one of the articles I read. Thanks for your effort.

tashasdaddy, I bought the seloc manual the same day I bought the motor, complete gear lube change, carb rebuilt and pump kit is all in the next stemp. I was just making sure the motor did run before I spent any money. Is there a real big difference between the oem book and the seloc?
In the BRP site they had 2 pump kits, a water pump kit and a chrome pump kit. anyone knows the difference?

I was thinking on not only do the tell tale, but add a water temp gauge or a water temp gauge or a combination. Anyone had done similar and have any pointers? I would be a little worried about the water house that have to got to the dash and the constant stearing of the motor. Maybe is not worth the trouble...

Thanks!

 

[1730V]

Re: 1975 70hp 70573-b Evinrude revival

There is no comparison between Seloc and OEM. OEM is far superior in a class all itself.

I've used Seloc/Clymers with frustration. They tend to leave you or run you in circles on the diagnostics. They're OK for basic maintenance. OEM manuals can be had at Ken Cook.

The chrome kit is for severe use, heavy silt, etc.

You really should check your compression before you do anything else. There is no sense in dumping a buch of $$$ into an engine that needs a rebuild.

As far as temperature goes, with the engine running, if you can hold your fingers on the top cylinder head for a few seconds, you're OK.

 

[Nandy]

Re: 1975 70hp 70573-b Evinrude revival

Sorry, I forgot to add it, that was the first thing i checked before buying the motor. I posted somewhere, there were from top to bottom like 158, 160, 160 or something like that. The one at the top had a 2 psi difference from the other, they were good.
I guess I will look into an oem and see what is it about.
About the temp and preassure gauge, I just wanted to be able to see it as im stering the boat. I can probably do fine without them, I mean, I dont have them in my Mercury. But I still have an interest on them. anyone has any input on it?

Thanks!

 

[1730V]

Re: 1975 70hp 70573-b Evinrude revival

Compression numbers are very good. As mentioned, the "telltale" can be added as explained in the FAQ's article.