6hp cooling problem

[2637042]

I just replaced the thermostat on my 67 6hp evinrude. with the old thermostat, water would only come out of the exhaust/water hole on the backside of the engine at mid to full throtle. i removed the t-stat and ran it for a day, and water flowed out at all times, (reverse, idle, and forward). when i put the brand new t-stat in it does what it used to, and when i idle for wxtended periods, the enging gets very hot. the water pump was just replaces, and all cooling passages are clear and able to flow plenty of water. any ideas on why there is no flow at idle would be appreciated.

 

[OBJ]

Re: 6hp cooling problem

Hi fishin'.....<br /><br />How hot is "hot"? Can you lay your fingers on the flat area on top just forward of the head for a few seconds? Or is it a no "touchy"? <br /><br />With the t-stat in, the water from the relief port won't flow till the t-stat opens up. And while yer under way, it may only be a mist.<br /><br />The t-stat should be a 143 degree t-stat. Was the t-stat PN 434841? This is the correct one. And did you replace the seal? Thats the rubber dohickey that goes around the rim of the t-stat.<br /><br />Keep us posted....thanks.

 

[2637042]

Re: 6hp cooling problem

when i remove the cover and touch the engine after it has been idleing for a few minutes, it it too hot to touch, and when i start going at a moderate pace, the water coming out of the exhaust/water port is very hot(steaming sometimes) this tells me that no engine cooling wat happening during the idle. also, when i bought a new t-stat from my local marine dealer i did not get a new rubber o-ring for it and used the old one. i planed on getting a new one, but if it were to be leaking, that would just allow more water through the system, which is the oppositite of my problem.<br /><br />thanks for your reply and maybe this info will help.

 

[2637042]

Re: 6hp cooling problem

i pulled out the t-stat and the old rubber seal around the base was broken. could this be the problem, and if it is will a marine dealer sell these?<br />thanks

 

[TLL]

Re: 6hp cooling problem

Sounds like your real problem is that the water pump won't pump at idle speeds. My guess is that the aluminum impeller housing and stainless wear plate are worn and scored. The new impeller does not fit tight to the plate and housing and creates an air lock at low speeds and no water flow. As you speed up, the air purges out of the pump, the pump primes itself, and it pumps water just fine. <br /><br />Todd