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			#1  
			
			
			
			
			
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|  I/O running temperature 
			
			I recently bought a 1982 V20, my first boat. It has a 170 hp Merc. that seems to run great. I notice that the temp. jumps to about 180 pretty quick then stays at about 200-210. Is this a normal temp or a little warm. I plan on changing the water pump as I don't know when the last one was put in, but am leary of running too hot in the mean time
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			#2  
			
			
			
			
			
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|  Re: I/O running temperature 
			
			Had the same deal - got towed in. The water pumps (impellers)are only good so long. The parts kit, which includes the housing, on mine were $55. Labor extra and involves taking off the out drive (it's inside). Good to go now - Might put in a new thermostat for cheap while your at it. 
				__________________ Pete 82 V-20 Merc 898 I/O 305ci V8 (gallery pg 5) | 
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			#3  
			
			
			
			
			
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|  Re: I/O running temperature 
			
			sounds pretty hot to me. my i/o runs at about 130-150 all day long.
		 
				__________________ hammer aint. stinkpot aint. sawdust aint. rainbow aint. maco sure as sh!t aint. randle? ha ha ha. | 
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			#4  
			
			
			
			
			
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|  Re: I/O running temperature 
			
			Mine runs cooler than that also, about 160 or 180, I forget the no. on the thermostat. I was told tho that if you keep it cool it helps cut down on the salt build-up. I would suspect something because I doubt you have a thermo rated that high.
		 
				__________________ bogey-free in E Greenwich RI on a 79 v-20 165 hp I/O | 
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			#5  
			
			
			
			
			
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|  Re: I/O running temperature 
			
			MY V-20 ORIGINALLY HAD A 470 MERCRUISER (170 HP.) THAT USUALLY RUNNED VERY HOT, SINCE THAT ENGINE IS FRESH WATER COOLED. NOW CHANGING THE IMPELLER IS ALWAYS A GOOD IDEA WETHER YOU USE THE BOAT OR NOT. IF THAT IS THE ENGINE YOU HAVE (470 MERC. 170 HP 4 CYL.) MY ADVISE IS GET RID OF IT AND REPLACE IT IF YOU CAN WITH A 4.3 MERC. SAME OUTDRIVE RATIO SAME HP (175 HP AT PROP.) I DID IT AND IS A GREAT ENGINE, VERY,VERY,VERY ECONOMICAL. THE 470 IS A GOOD ENGINE, BUT BEING A 4 CYL. WITH BIG (5.250") PISTOS IS VERY DIFFICULT TO TIME IT SPECIALLY WHEN OLD, AND THE PARTS ARE VERY DIFFICULT TO GET BECAUSE IS A MIXTURE OF DIFFERENT ENGINES, PISTONS ARE FORD, VALVES ARE GM, PAIN IN THE NECK. LESTERUS | 
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			#6  
			
			
			
			
			
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|  Re: I/O running temperature 
			
			Owners manual on my 5.7 Mercruiser says 160 degrees. I was running hotter and had a new thermostat (i think 140 degrees) put in and a couple barnacles in the intake cleared. runs perfect now. I was running +200 prior to the fix and that's too hot for my engine.
		 
				__________________ 1984 248 Sportsman w/1999 5.7L EFI Mercruiser 2001 Carolina Skiff J16 w/2005 25hp Yamaha tiller control | 
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			#7  
			
			
			
			
			
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|  Re: I/O running temperature 
				__________________ Formerly - 89 cuddy 165hp I/O and 95 V21 / 150 Honda When the people fear their government, there is tyranny; when the government fears the people, there is liberty. - Thomas Jefferson | 
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			#8  
			
			
			
			
			
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|  Re: I/O running temperature 
			
			Hey 76GMC1500, Why do you want the engine to run on the hot side? Curious as to the mechanics behind that. Thanks 
				__________________ Pete 82 V-20 Merc 898 I/O 305ci V8 (gallery pg 5) | 
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			#9  
			
			
			
			
			
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|  Re: I/O running temperature 
			
			Hotter will keep you from fouling plugs but can be hard on the heads.
		 
				__________________ 1978 V20 Cuddy w/ 225 Johnson. And Several other boat's | 
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