How do I get to water jackets?

[rocks]

Been fighting an over heat problem for the last year.New water pump,poppit,therms,trigger assy,temp sender.I think I may not be getting a good enough flow at high RPM'S.Is it hard to clean the water jackets?1983 mariner 150

 

[Laddies]

Re: How do I get to water jackets?

rocks, I think if you are not sure about the location of the water jackets of your engine, it would be a good investment to buy a OEM manual for your engine, also without experence removing bolts on a saltwater engine you a flirting with disaster. You might condsider professional help. That being said have you removed the the intake screens from the water pump intakes to ck for impeller debree

 

[andy6374]

Re: How do I get to water jackets?

Have you tested the water pressure?<br /><br />Before attempting to remove the bolts spray em' down with some PB plaster. Even try a mapp torch.<br /><br />When loosening the bolts, I find it's best to go back and forth if it seems like the bolt doesn't want to come out. That is, try loosening it then tighten it. Give it some heat, spray a little more PB, back and forth...some heat...you get the idea. Breaking the bolt isn't the bad part, it's striping the internal thread that sucks and then you have heli-coil it which can also be troublesome.

 

[rocks]

Re: How do I get to water jackets?

Andy, I have great water pressure 18-20 psi at 3000 rpms.and I have a manual just to lazy to read it.I will probaby take to shop if it requires removeing the heads.

 

[andy6374]

Re: How do I get to water jackets?

This sounds like a dumb question, how do you know it's overheating? Infared thermo.?<br /><br />Remember the manual is your friend.<br /><br />I don't think Laddies was intending to scare you away from the task, but rather to just be aware that those bolts will be stubborn to get out. Don't give up yet.

 

[rocks]

Re: How do I get to water jackets?

Andy, the alarm goes off at 3000 rpms and has been for the last year.Have had it to the shop a couple of times.Laddies didn't scare me,just more than i wanted to tackle myself.The boat has been a saltwater boat its whole life and acts like I have poor water circulation at high rpms.

 

[andy6374]

Re: How do I get to water jackets?

Sorry for the long reply-<br /><br />Are the heads super hot to the touch when the alarm goes off? They should be hot, but you should also be able to keep your hands on them for a couple seconds.<br /><br />I am not ruling out your idea that the water jacket is clogged, in fact this might be the problem. Try removing the tstats and sticking a hose in the tstat holes. Drop the lower unit and see if any debris falls out of the water tube.<br /><br />Physically test the temperature of heads because the overheat switch might be at fault (even though it's new) and you would end up paying someone to remove the heads when it wasn't necessary. Autozone as a tool loan program, you could borrow an infared thermo. there.<br /><br />Have you ever had the head cover gasket or head gasket changed out? I've read here on the forum that if the gasket is blown it could let hot exhaust gases into the cooling system, thus resulting in overheating. Just throwing another idea out there.

 

[rocks]

Re: How do I get to water jackets?

Thanks for the info,I will try those things.the heads are super hot when alarm goes off too hot to touch.If it's not the jackets I may be forced to unbolt her in about 50' of water.This problem has been very frustrating.