finally got my 470 merc out to the water

[fmalott]

rebuilt 1983 470 alpha one. i got to test run the boat in the water all went ok just a couple of things. charging system went ok(i did the conversion). the oil pressure went to 80 lbs at the beginning but then it went to 40lbs idle 60lbs WOT after it got to operating temperature. the temperature would not go above 125-130, i have a new thermostat and sensor installed. the boat at WOT i got 35 mph at 3500 rpm. does anyone have a comment on the oil pressure and temperature?

 

[wrestling coach]

Re: finally got my 470 merc out to the water

I have the same year and engine as you in a 19' Grady White Tournament. Boat is new to me this year. All my numbers compare to yours except the temp. Mine runs at 160* most of the time. Since it has a 160* stat that's what I would expect. It will climb a bit to 175*-180* on a long run at 3000 RPM, 30-32 SOG on the GPS. Temp falls back to 160* quickly as I idle or troll. Running mine in the St. Lawrence River near Cape Vincent, NY.

Dennis

 

[stonyloam]

Re: finally got my 470 merc out to the water

The temp reads a little low, should be about 160, BUT, my temp gauge has never read above 140 since I got it in 91, so I suspect that your gauge is off. You could check with a IR thermometer or a radiator cap thermometer. When you have a good idea where you are, mark your gauge and keep an eye on it. Your WOT is a little low, but there again could be your tach. If you have a dwell meter/tach check it. Your WOT should be 4200-4400. Check your prop size, should be stamped on hub. Oil pressure, mine does almost exactly the same thing. Remember you are running pretty heavy oil, either 30W or 25/40 so initially I would expect it to be high. Glad to see the old gal on the water have fun.

 

[fmalott]

Re: finally got my 470 merc out to the water

i'm going to borrow a IR thermometer to make sure what the temp is. the only thing i did was change from a 13-1/2" three blade to a 14" 4 blade prop the pitch is the same as far as the oil goes i kinda thought it was because of the thicker oil and as far as the gauges go they work BUT they are original to 1983