Mariner 40hp cooling system

[Paul F]

For info on some engines the water take off for the tale tale is on the supply to head and block cooling or off of stat housing and therefore a small hole is supplied at the end of the tale tale so that not all the water is spat out via the tale tale (back pressures it)

[tue]

Daniel

It is nothing to worry about really. The Mariner 40 will have a temp sensor on it which in the event of the engine overheating will sound a buzzer in the control box (at which point you rapidly turn off engine).

When you pick your boat the dealer should go through it with you running and explain how and when water will flow from the tell tale. Once you have used it a couple of times you will get used to how long it takes for the tell to get up to full pressure and know when its been a bit too long and stop engine to make sure.

[ribfreak]

The discussion of this thread is very similar to likewise ones in other forums- when will there be somebody of the outboard- designers noticing it? The prices for these motors are arificially held to an exorbitant level- a pressure gauge for cooling water is not such a miracle anymore that they couldn`t supply it with the motor?! Or do these guys want us to burn them- good for their sales-numbers when the stupid user buy new ones more often....
greetings,
Wolfgang

[tue]

What you need to buy is an Optimax. That way you get the privalge of £500 worth of Smartcraft guages that shows you the block water pressure

[Daniel TD5]

feel a bit better now seeing that most engines are the same me being
new to this i though the engines were well made due to the high purchase
cost at least its got two year warrenty on it. but valiant give five years
on the boat and they cost about the same

[Turbodiesel]

The tell tale oulet is modified by us for the RNLI Mariner 40s, ( hope i dont get told off for tell people this!!)

We take the tell tale fitting off, drill the hole out to i think its 10mm and push the hose through the hole. Then put a cable tie on the outside of the cowl tray to stop the hose going inside the cowling.

We have done it to stop it getting blocked up. It wont effect your engine.
The RNLI have been using this system for a long time with no problems.

I spent hours measuring temperatures and water pressures on these engines and gradually made the tell tale hole bigger and bigger to make sure the would be no effect on the engine.

[Turbodiesel]

Also forgot to say, the tell tale should come out immediatley, they do have a thermostat but when its shut it will still have a tell tale. Thw cooling water will not be going around the powerhead while the Thermostat is shut.

Some of the older mariners only have a telltale when the engine is hot, and
the V6 engines are thermostatically controled which is why the telltale pulses, rather than having a contstant water flow.

[Daniel TD5]

if i make the mod to the engine by drilling the tell tail out to 10mm will this affect
the warrenty from mariner

tims who started this thread has a ex RNLI engine so i wonder why his had not been done before

[Tim M]

Mine's an ex RNLI Mariner 40 - but it has a regular tiny fitting on the end.
I'd never considered removing the fitting. I think I'll do this; it's too dam small!!

[Ribald]

I used to have the same problem on my Mariner 60 - many palpitations were suffered until my engineer told me not to worry about the strength of the t/t stream. The t/t on my current Suzuki is so strong I'm sure it could move the boat on it's own at a push. It can also be rotated so I can play at being a jet-ski if need be .

Would drilling out the outlet fitting out not raise a possible problem with back-pressure (or lack of it) i.e. too much water though the t/t = not enough water going round the block?

[roohairy]

If you do ever 'cook' an impeller you'll be getting bits of it stuck in the cooling system for ages afterwards - any tricks for flushing for you engineers? I had problems with an engine that had been run in surf off an sandy beach and the housing for the impeller was scoured, if you're in any doubt change this as well as it drove me mad for 2 years before I figured it out and numerous impellers. Now good as new... Also have an old Suzuki with a 13 year+ impeller in it is this a record?

[Turbodiesel]

Yes it does effect the water pressure but only by a very small amount, I cant remember the figure. But its not enough to effect the engine.