1974 Evinrude 70 hp Overheating

E

edgutgesell

Petty Officer 2nd Class
Joined
Jul 18, 2004
Messages
144
I have a 1974 Evinrude 70 hp and I would like to have a good way of checking the cooling system while running. The engine does not have a waterpump telltale (pee hole). Can some type of water pressure gauge or other monitor be retrofitted that would indicate the water pump's condition? This engine is in near new condition (used 3 seasons in the past 30) and I get nervous when I can't determine if the water pump quits. Thanks in advance for your replies!<br /><br />Ed G.
 
Chinewalker

Chinewalker

Fleet Admiral
Joined
Aug 19, 2001
Messages
8,902
Re: 1974 Evinrude 70 hp Overheating

Hi Ed,<br /> Step one - if you don't know when the waterpump was changed last - change it! Just because it hasn't been used doesn't mean the pump is good. Pumps age MORE with none-use than with regular use!<br /><br /> Step two - I'd head to your local marina and see if they have a newer 70hp in the shop, maybe something from the early 1980s and see where the telltale outlet is on the exhaust manifold. You might be able to either replace your manifold with a newer one or drill yours and tap it for an NPT nub to accept a telltale hose. Then, route the hose out lower cowling in the location of your choice. Use 1/8-inch tubing.<br /><br />- Scott
 
S

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: 1974 Evinrude 70 hp Overheating

You should have an overheat alarm in the control box. It needs to be tested once in a while. Another useful aid it to install an after market temperature gauge. Add a pressure gauge and you pretty much have all the bases covered.<br /><br />First thing though is to follow Scott's advice and install a new water pump. Give some thought to a new thermostat as well.
 
P

phatmanmike

Captain
Joined
Oct 24, 2003
Messages
3,869
Re: 1974 Evinrude 70 hp Overheating

i have a 1976 johnson, and if yer reallllly nice, i can try to post a pic of the exhasut manifold.<br /><br />scour ebay and see if anybody is parting one of these out.<br /><br />easiest thing to do is get an exhaust cover from a 76-84 70hp or do as chiney boy said and drill a hole and tap it and make a "tell tale"<br /><br />i did this with a 72 50hp and all worked well
 
E

edgutgesell

Petty Officer 2nd Class
Joined
Jul 18, 2004
Messages
144
Re: 1974 Evinrude 70 hp Overheating

Thanks for the replies. The first thing I did when I returned the motor back in service was to rebuild the water pump and replace any parts that would become brittle with age. I have the 74 Evinrude repair and parts manual, however, I don't have a later manual that shows the exhaust manifold with the telltail, so a picture showing the later manifold would be really helpful.<br /><br />Scott, I suppose that using 1/8" tubing is to limit the amount of cooling water that the telltail uses. Is that correct? <br /><br />Ed G.
 
You must log in or register to reply here.
Top