Chronic overheat 1990 150 XP Evinrude

[ezeke]

Re: Chronic overheat 1990 150 XP Evinrude

Is the purpose of the deflectors to maintain unidirectional flow around all the cylinders and drain out at completion at the other end?? When someone stated that cleaning the water passage ways, does that meaning a manual scraping around the jackets??

Sorry, I have no intentions of hijacking this thread, but since it is somewhat relevant to subject at hand I thought I would ask. It is funny, but none of the service manuals that I have purchase, discuss water deflectors or maintaining patency of the water passage around the heads.

Pardon the interuption Lizardo.

In the case of the picture that I posted above, the old deflectors have partially blocked the passages that should be open. The deflectors on that engine need to be replaced and the passages clened where the blockage (probably calcium) is obstructing the flow of water.

I have marked up and expanded a diagram from a Seloc manual; if you look closely you can see the arrows that show how the water should flow with the deflectors properly in place in a V6 crossflow engine.

 

[lizardo]

Re: Chronic overheat 1990 150 XP Evinrude

Thanks so much for this drawing -- it is clear that it would have significant impact on the cooling. We are in Mexico where this boat lives, and parts are not easy to come by -- so will probably have to get new gaskets when I take it apart to put in deflectors. I can probably get 3/8 hose locally and am anxious to give this a try. Thanks

 

[Dhadley]

Re: Chronic overheat 1990 150 XP Evinrude

What's the 3/8" hose for? Just curious.........

 

[lizardo]

Re: Chronic overheat 1990 150 XP Evinrude

We are so excited! Checked the compression and it was fine. Then took off the heads and examined -- lots of salt crystals and gunk -- but, on the hottest side were 3 melted globs of rubber hose and on the other side were none! The cooler side does overheat after awhile (no deflectors at all) but the melted globs will soon be replaced with 3/8" rubber hose (which we should be able to get here in Mexico) and then we shall see. Hopefully we can get by with the old head gasket for a trial anyway. But -- I think you found the problem. Thanks and we will be back after a trial.

Dan

 

[lizardo]

Re: Chronic overheat 1990 150 XP Evinrude

deflectors -- In another overheat discussion we read that 3/8" rubber hose can be used to make the deflectors. Hope that is true. Do you see a problem?

 

[lizardo]

Re: Chronic overheat 1990 150 XP Evinrude

Seems I miscommunicated our progress. He just opened one side and all the deflectors were there and melted into globs. Expect we will find the same thing on the other side so perhaps there is another reason one side is hotter than the other.

 

[Dhadley]

Re: Chronic overheat 1990 150 XP Evinrude

Not sure but I think a 3/8" ID hose is too big. The deflectors are actually a piece of one side of the old dual line gas hose. If you use something too big you'll be right back to having the hose block an area it shouldn't.

 

[lizardo]

Re: Chronic overheat 1990 150 XP Evinrude

The 3/8" hose seemed to fit just fine and the boat is now out and after an hour of running at all speeds, is running great!!!!

Thank you all for your advice and support -- I hope this is the end of a 3 year long problem, a lot of frustration and many replaced parts!!!

Of course I realize there is always a new issue when you have a boat -- but for now we are delighted. Now to do some fishing!