470 mercriuser

[fadygyounes]

i have 470 mercriuser 1979 <br />i have a problem with over heating first i changed the head gasket and the impella in the leg still over heating <br />ps i clean the risers and did the presure test for the cooling system every thing was ok<br />any hints thank you best regards

 

[Trent]

Re: 470 mercriuser

Does it do this all the time? Idle? Cruise? Put a clear hose on the hose comming from the transom plate (looks like heater hose) to the theromstat housing..Get somone to drive the boat at cruise and you look at the clear hose. If their are bubbles in the hose the problem is in the outdrive and not the engine. If no bubbles go back and make sure the heat exchanger is not plugged up. Are you losing coolent? Water in the oil? Thermostat ok? You have several things to make sure of.

 

[fadygyounes]

Re: 470 mercriuser

please can you drow a small picture where the hose coming from into the heat exchange so i can change the write one

 

[trevorcday]

Re: 470 mercriuser

I fixed an overheating 470 recently. The problem turned out to be the seawater supply tube that goes from the outdrive to the transom assembly. it had been replaced with a piece of automotive heater hose that kinked when the drive was down all the way. This tube must be the proper thick walled tube supplied by Merc and in exactly the right length to prevent kinking.

 

[nickster]

Re: 470 mercriuser

fady!<br /><br /> We had a problem with a 470 over heating after changing every thing it still over heated. The problem was between the transom pick up hose and the water cooled voltage regulator. We had to pull the lower unit and then pull the hose off at the voltage regulator coming in and thenwe blowed compressed air trough the hose both ways. eventually we got some debree out of it and put everything back together and it never overheated after that.<br /><br />GOOD LUCK!<br />Nick