BarCrusher Posted February 1, 2011 Share Posted February 1, 2011 Hi Raiders, I have just purchased a new boat with a 40hp Merc on the back (1998). The outboard appears to be in immaculate condition, but what I have noticed after taking it out for the first time on the weekend is that the water that is being flushed out in unusually hot and to the point where you cannot leave your hand under it. Was wondering if any of you guys have experienced this on your end? Is this normal? and if not what are the possible issues? In past experience my motors always flush cold/luke warm water, and my brother has a 75hp 2006 Merc which also flushes cold... Any assistance would be greatly appreciated. Cheers Bill Link to comment Share on other sites More sharing options...
fishon Posted February 1, 2011 Share Posted February 1, 2011 Hi Raiders, I have just purchased a new boat with a 40hp Merc on the back (1998). The outboard appears to be in immaculate condition, but what I have noticed after taking it out for the first time on the weekend is that the water that is being flushed out in unusually hot and to the point where you cannot leave your hand under it. Was wondering if any of you guys have experienced this on your end? Is this normal? and if not what are the possible issues? In past experience my motors always flush cold/luke warm water, and my brother has a 75hp 2006 Merc which also flushes cold... Any assistance would be greatly appreciated. Cheers Bill ask huey mate but im guessing if its still flushin water might not be the impeller but maybe the thermostat or wouldnt be a bad idea to replace both shell be runnin sweet as Link to comment Share on other sites More sharing options...
dunc333 Posted February 1, 2011 Share Posted February 1, 2011 i would change impellor and thermo for piece of mind .it should not flush that hot.how long are you flushing engine for?if you have handheld thermometer put under telltale or at prop where water also comes from you should not be over about 60 degrees at idle.let us know how you go. Link to comment Share on other sites More sharing options...
BarCrusher Posted February 1, 2011 Author Share Posted February 1, 2011 i would change impellor and thermo for piece of mind .it should not flush that hot.how long are you flushing engine for?if you have handheld thermometer put under telltale or at prop where water also comes from you should not be over about 60 degrees at idle.let us know how you go. Im flushing for approx 5mins. i will give the thermometer a go. The water from the telltale and near the prob are much cooler than the water coming from the hose outlet. Thanks for your responses peoples!! Bill Link to comment Share on other sites More sharing options...
NickF Posted February 1, 2011 Share Posted February 1, 2011 The water from my telltale is always quite hot, you can't leave your hand under it for long. That's normal 2-strokes need to run hottish. Link to comment Share on other sites More sharing options...
Yarraone Posted February 1, 2011 Share Posted February 1, 2011 i have a 90hp mecery 2 stroke and the flush is always quite cool??? Link to comment Share on other sites More sharing options...
NickF Posted February 2, 2011 Share Posted February 2, 2011 Well if you think about it, cold water is being inducted into the cooling system to reduce the temperature of the engine, and therefore should come out hot after running through the cooling channels inside the head. Can't imagine why the telltale would spit out cold water still after going through the head unless the thermostat was stuck open or had been removed. This would then mean your engine may be running under optimum temperature. Link to comment Share on other sites More sharing options...
BarCrusher Posted February 2, 2011 Author Share Posted February 2, 2011 Hi All, I think I may have gained some progress on this situation. I ran the engine yesterday with new muffs and let it run for some time what I noticed is at the initial stages of the water getting sucked through the water temp is vary hot (75 deg) and this is due to the water taking its time (30+ sec) to get through and pump out the other end and the water flow/pressure is not consistent. After a few minutes of proper pressure and flow, the water cools down to a more reasonable temp (50deg). So I’m guessing the problem lies within the pressure of the water pumping through i.e. impeller... Because when i raised the idle (choke) the flow comes through much more easier and stronger and therefore much cooler temps. I think the muffs themselves may be a problem because no matter how i positioned it, water would leak through the sides of the muffs and when I would hold and press them together water would begin flowing much more consistently. What are your thoughts? Thanks for your help. Bill Link to comment Share on other sites More sharing options...
fishon Posted February 2, 2011 Share Posted February 2, 2011 Hi All, I think I may have gained some progress on this situation. I ran the engine yesterday with new muffs and let it run for some time what I noticed is at the initial stages of the water getting sucked through the water temp is vary hot (75 deg) and this is due to the water taking its time (30+ sec) to get through and pump out the other end and the water flow/pressure is not consistent. After a few minutes of proper pressure and flow, the water cools down to a more reasonable temp (50deg). So I’m guessing the problem lies within the pressure of the water pumping through i.e. impeller... Because when i raised the idle (choke) the flow comes through much more easier and stronger and therefore much cooler temps. I think the muffs themselves may be a problem because no matter how i positioned it, water would leak through the sides of the muffs and when I would hold and press them together water would begin flowing much more consistently. What are your thoughts? Thanks for your help. Bill nick f is definately right water shouldnt be cold every outboard ive owned pumps warm water just a question barcrusher are you letin the water run cold through the hose before you hook it up to the motor cos in this weather the water in the hose will be hot as Link to comment Share on other sites More sharing options...
BarCrusher Posted February 2, 2011 Author Share Posted February 2, 2011 Yep definitely waiting for the cooler water... yeah and from what I hav been reading the water being warm is not that unusual. Cheers Link to comment Share on other sites More sharing options...
NickF Posted February 3, 2011 Share Posted February 3, 2011 It should be hot enough that you can only keep your hand under it for a short time before it hurts, but not cold enough you can leave your hand under it forever. That said smaller outboard may produce less internal heat therefore cooler telltale temp. Mine is a V6 2-stroke so it may be that it runs hotter than others. Either way if you have 50C water coming from your telltale that's a good thing as long as it's not cold. Link to comment Share on other sites More sharing options...
BarCrusher Posted February 3, 2011 Author Share Posted February 3, 2011 Thanks for the feedback nick Link to comment Share on other sites More sharing options...
pjbink Posted February 3, 2011 Share Posted February 3, 2011 Another point to consider is that a lot of small outboards don't get enough water from ear muff type flushers. They have a screw hole usually next to the oil drain plug where you are meant to screw in a attachment which you are able to attach a hose. You are also meant to cover up all the other water intakes so that the water just doesn't go straight back out. I'm not sure if this is the case with your Mercury but it is worth checking. Link to comment Share on other sites More sharing options...
Guest Aussie007 Posted February 4, 2011 Share Posted February 4, 2011 hold your hand under the pee'ing stream if this stream goes hot than cold than hot over a period of minutes than your engine is working correctly if it stays hot the thermostat is stuck closed if it stays cold your thermostat is stuck open on a new tohatsu i had the water from the exhaust port would go really hot to the point u could not stand it than it would go nice and cool and repeat this process with 0 hours on the engine 2010 model from the shop Link to comment Share on other sites More sharing options...
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