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Series 102 water cooling

Posted: Sun Jan 06, 2019 3:20 pm
by african imp
I have recntly re built a series 102 motor, the water cooling from the cylinder head take off goes via a rubber pipe to the chromed fitting part way down the large stainless steel exhaust pipe.

The fitting has three entries or exits, when the motor is running and in a tub of fresh water the rubber pipe gets hot, so water is flowing ok but there is no water exiting the exhaust pipe tube as this picture shows, so with my engine all waste cooling water water is going into the exhaust tube.
Is this acceptable?

Re: Series 102 water cooling

Posted: Sun Jan 06, 2019 4:40 pm
by blokewithaboat
Looks fairly normal from what i can see.

You are correct in that some of the cooling water discharges from INSIDE the exhaust tube.
This is normal and it's how a 102's cooling system works.
The "pee hole" exit point that's half way down the exhaust tube is the only way of seeing that water is flowing .


Nice motor by the way 8)
Have i seen this from somewhere before?

Re: Series 102 water cooling

Posted: Sun Jan 06, 2019 4:45 pm
by Charles uk
How do you know "all" the water is going down the exhaust?

Remove the rubber exit tube so you can see any water output.

Cooling water seldom exceeds the temperature of your fresh urine when running at full revs.

Re: Series 102 water cooling

Posted: Sun Jan 06, 2019 7:25 pm
by african imp
Gents, I used a file picture from SOS and Johns site, it shows what should be right? or is it wrong?
As my coolant exits in the exhaust pipe.

Re: Series 102 water cooling

Posted: Sun Jan 06, 2019 9:19 pm
by RickUK
The visible flow is really only a 'telltale' to let you see that water is flowing - as long as you see water and not steam assume all is well - I assume from your other emails you don't have a propellor fitted yet - when you do, and if your motor doesn't have a 'neutral' selector, running it in a barrel will virtually eliminate any flow due to the water roaring past the intake holes!

Re: Series 102 water cooling

Posted: Sun Jan 06, 2019 9:25 pm
by Charles uk
Do you have the fitting in the exhaust like the file picture, as these are designed to act as a tell tale & let most of the cooling water spray outside visibly.

You should have at least 2 litres per minute coolant flow, at above 1500 revs.

Re: Series 102 water cooling

Posted: Sun Jan 06, 2019 10:45 pm
by blokewithaboat
It's possible you might have the wrong fitting on the exhaust tube.
They look the same as that fitted to the top of the engine block, but the fitting that goes onto the exhaust tube has 3 inlets/outlets as you've mentioned.

Are you sure it's not blocked due to carbon from the exhaust itself. I've seen that before often enough.




Better still, try and show us what the problem is by uploading a picture or two. :P

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 6:06 am
by african imp
This image shows the motor running and when not in gear, I see no water comming from the chromed side outlet, the black rubber pipe was hot, so I assumed it was from hot water, was it from steam?

I have since blown the pipe out with an air line, I did think there was a small blockage but not much, its clear now.

The top fitting on the block has two holes, the fitting on the exhaust has three holes, all are clear.

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 9:22 am
by Charles uk
How do you know "all" the water is going down the exhaust?

Remove the lower end of the rubber exit tube so you can see any water output, please.

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 11:12 am
by african imp
Charles , another test and with the rubber hose removed showed that no cooling water is coming from the black rubber transfer hose.

A blow with a high pressure air line had lots of air bubbling out of the leg down in the water tank, so the feed line is clear, any ideas on what I need to next?

The pump impellor was in good condition.


regards, Roy

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 12:40 pm
by african imp
Can I assume that this is or should I say WAS the feed from the pump to the water cooling in the cylinder head?

Since fitting the rubber tube has collapsed, I think an air line will blow past the kink but the Seagulls water cooling pump will not?

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 1:05 pm
by african imp
I have now repositioned the same rubber tube, it is new and in good condition, the copper pipe was also moved and towards the rubber tube.

Should hose clamps be fitted here, black cable ties may work ok and look neater?

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 1:21 pm
by african imp
Cable ties work and cannot easily be seen?

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 1:50 pm
by Charles uk
Why not remove that connector tube & test to see if the pump is pumping, in your test tank with that pipe just above the water level.

If that pipe kinks or comes loose in use, rowing home with a seized engine in your local pond wouldn't be life threatening, but there are a lot of circumstances where it might be!

I've never had to use hose clamps there & never noticed anyone else doing so.

Re: Series 102 water cooling

Posted: Mon Jan 07, 2019 7:58 pm
by blokewithaboat
Mr African imp

i've sent you a private message.