Cooling System..

willisballs

Cadet
Joined
Apr 7, 2004
Messages
29
On a 1976, 135hp Evinrude, when at idle and low speeds(below plain), water comes out the back two holes under the hood in the rear....((the "****-line?" out the side is fine)), but at higher speeds, the water output out of the back is reduced to almost none....is this normal, and are all engines supposed to put water out through these holes(is it part of the cooling system....(b/c, at we think, running at WOT or near it for a some time makes it overheat... thanks
 

willisballs

Cadet
Joined
Apr 7, 2004
Messages
29
Re: Cooling System..

Any tips for replacing the impeller......1976 135hp Envinrude..... THanks
 
D

DJ

Guest
Re: Cooling System..

Your system is working backwards. The "exhaust relief" holes you describe should have a higher flow at planing speeds, not the other way around.<br /><br />I would be looking at:<br /><br />Thermostats<br /><br />Impeller kit<br /><br />Coolant defletors (under heads)<br /><br />If I did anything first, it would be the impeller KIT.<br /><br />As many outboards as I have worked on, I rarely do anything, except routine maintenance, without a manual. Or, at least, a parts breakdown page.<br /><br />You really need a manual. Look at the lower left corner of the header page.
 

Cricket Too

Lieutenant Commander
Joined
May 14, 2003
Messages
1,732
Re: Cooling System..

DJ, wouldn't there be more backpressure at idle than at cruising speed(planed off) when the prop is pushing the water out of the way of the exhaust coming out of the prop? Just a quetsion, I may be confused.
 
D

DJ

Guest
Re: Cooling System..

That's why I think your impeller is weak. The pump, and forward motion, need to keep that exhaust housing FULL of water to prevent it from overheating.<br /><br />Yes, you have more backpressure, but less pump flow.<br /><br />They should "spit" at idle and "flow" at speed.
 

willisballs

Cadet
Joined
Apr 7, 2004
Messages
29
Re: Cooling System..

So....if my engine spits fine at idle and before plane, but after plane it has little water coming out the exhaust relief holes, it is probably the pump thats faulty?.....When looking into working on the coolong system(water pump, impeller, etc..) it is difficult to find anything but an impeller kit.... Is this what should be done when replacing the impeller? note.(somone else recommended..do not just replace the impeller but the ?housing? too...is he right? and if so...what part(s) is it i need to find?)...we are trying to replace whatever we need to..since its been awhile, but the only parts we are finding for 1976 Evin. 135hp is an impeller kit... thanks alot, guys
 

bubbakat

Captain
Joined
Oct 29, 2002
Messages
3,110
Re: Cooling System..

Willis I have one of these same year and h/p .You can get the water pump kit at your local johnnie rude dealer and it has the impeller and seals and new plate and cup. The plate is the updated style,<br />It is simple to install but you do need the manuel.<br /><br />I would get the oem manuel because it has a lot of good info in it.
 
Top