Cooling System

brinky · 26 July 2013, 12:50

Hi all,

Is there a simple way of checking that the cooling system is ok on my 50hp, 2 cylinder, 2 stroke outboard. The pee hole is clear and seems to pump water well, but I have been told that doesn't mean the whole cooling system is clear !!

Thanks for any advice ..

4str · 26 July 2013, 14:23

The nature of the flow from the pee hole is diagnostic of engine problems like a weak water pump or clogged system. I would tend to believe the pee port and not worry as long as the flow is strong or hasn't changed how it looks.

That said I just installed a water pressure gauge on my new 150 Yamaha. The theory is that it will help me monitor the cooling status both short term and over time. My gauge set only has idiot lights for engine temp and pressure and I feel better with at least one real gauge.

Poly · 26 July 2013, 20:15

What are you trying to do?

(1) Make sure its all OK now just in case?
(2) Investigate a problem / something you are worried about?
(3) Track developing issues over time (e.g. clogging of the water ways in the head)?
(4) Spot a problem quickly at sea before the engine goes bang?

Probably 4 different answers.

paddlers · 26 July 2013, 20:27

I have a Mariner 135hp V6 that has a new impeller and was peeing well but just for curiosity took the thermostats out for a look and discovered that one was not working & both were covered in crap!
Cost about £30 for two new ones with gaskets which is a cheap way of hopefully relaxing that it's one less thing to worry about on the jollies next week.....
Basic stuff I know but better than risking two weeks ploughing about in the kids SIB

brinky · 26 July 2013, 20:30

I may have a problem with over heating, hopefully I'll get out over the weekend, if I loose power again I'll by pass the thermo switch to see if it makes a difference.

Poly · 26 July 2013, 20:44

Quote:

Originally Posted by brinky

I may have a problem with over heating, hopefully I'll get out over the weekend, if I loose power again I'll by pass the thermo switch to see if it makes a difference.

Does your engine have an overheat alarm and is it working? I wouldn't rely on one to give sufficient early warning to prevent damage though. If I was worried things were getting hot I'd be inclined to fit a little temperature probe to the head and keep an eye on it.

9D280 · 28 July 2013, 00:03

Quote:

Originally Posted by brinky

I may have a problem with over heating, hopefully I'll get out over the weekend, if I loose power again I'll by pass the thermo switch to see if it makes a difference.

What makes you think you have a heat problem? If your control box is beeping heat tunes then it either means a faulty sender or a genuine overheat.

As Poly says, probably worth having some form of monitor in place if you disconnect the temp switch as a genuine cooling problem will cause much grief if you bypass the alarm & let it cook...

Nos4r2 · 28 July 2013, 00:07

Hmmm... 50hp, 2 cyl , and old tech at a guess.Prob no beeper.

Either get an IR thermometer and point it at the block while it's running, or a more basic way is to extend the pee hose to above the powerhead and see if it carries on peeing. If it doesnt, your water pressure isn't enough to reach all the block. That won't tell you if your cooling system's blocked though, just that you've got enough pressure.

breghall · 28 July 2013, 00:33

A pee stream only tells you that it's working, it gives no indication of strength of the flow at wot. If you haven't changed the impeller in a few yrs then do it now, better be safe than sorry

brinky · 28 July 2013, 20:25

Quote:

Originally Posted by 9D280

What makes you think you have a heat problem? If your control box is beeping heat tunes then it either means a faulty sender or a genuine overheat.

As Poly says, probably worth having some form of monitor in place if you disconnect the temp switch as a genuine cooling problem will cause much grief if you bypass the alarm & let it cook...

It's a suggestion from selva uk, I only want to bypass the thermo switch and run the engine briefly to see if I get full power.

brinky · 28 July 2013, 20:31

Quote:

Originally Posted by Nos4r2

Hmmm... 50hp, 2 cyl , and old tech at a guess.Prob no beeper.

Either get an IR thermometer and point it at the block while it's running, or a more basic way is to extend the pee hose to above the powerhead and see if it carries on peeing. If it doesnt, your water pressure isn't enough to reach all the block. That won't tell you if your cooling system's blocked though, just that you've got enough pressure.

Don't think I do, I have a beeper that tells me when the oil level is getting low....