I must fit a coolant reservoir to my 8-year old Beta 13hp.

Er .... not really pvb ...... I did state in my posting "other efforts have not prevented overheating at prolonged high revs" and clearly asked for help from the motorcycling fraternity - not a general reply on how a beginner might solve an engine overheating problem.
Nevertheless - thanks for your input.
Ken
what engine did the Beta replace
 
Perhaps you've already done so but have you actually talked to Beta Marine about the problem? By reputation they are reckoned to be helpful with technical issues on existing installations although I've no personal experience of this having only just acquired a Beta 20 (along with the yacht it's in!)
 
Er .... not really pvb ...... I did state in my posting "other efforts have not prevented overheating at prolonged high revs" and clearly asked for help from the motorcycling fraternity - not a general reply on how a beginner might solve an engine overheating problem.
Nevertheless - thanks for your input.
Ken

Have you done a flow check on the cooling water? It is difficult to tell by looking at it whether there is enough.

What revs are you running it at when it overheats, and what revs to you get at max throttle? What prop are you using, and is it clean? Is there plenty of antifreeze/coolant in the cooling water? Is the pressure cap working at the correct pressure? Is the thermostat ok? Is the exhaust system ok?

Like Sailorman, I find it hard to see how a lack of header tank is your problem, or that installing a header tank will solve it. Have you asked Beta about this - they are usually very helpful?
 
Have you done a flow check on the cooling water? It is difficult to tell by looking at it whether there is enough.

What revs are you running it at when it overheats, and what revs to you get at max throttle? What prop are you using, and is it clean? Is there plenty of antifreeze/coolant in the cooling water? Is the pressure cap working at the correct pressure? Is the thermostat ok? Is the exhaust system ok?

Like Sailorman, I find it hard to see how a lack of header tank is your problem, or that installing a header tank will solve it. Have you asked Beta about this - they are usually very helpful?

What is "overheating", is the gauge correct. Most engines do not like overheating as something, usually bad, happens to it soon after. I had a Pugeot Citroen 1.9 & they did not like over heating at all, before the light came on the head gasket was blown
 
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Er .... not really pvb ...... I did state in my posting "other efforts have not prevented overheating at prolonged high revs" and clearly asked for help from the motorcycling fraternity - not a general reply on how a beginner might solve an engine overheating problem.

Sailorman suggested that it had to be a heat exchanger problem. I suggested, and Vyv Cox seems to agree, that it might be an insufficient flow of seawater. Your original post didn't say that there was adequate cooling water flowing, so it was a natural thing to suggest.

If you look back at previous posts concerning Beta engine overheating, a number of them seem to be the result of inadequate seawater intake. I'm not saying yours is, of course, just that other people have found this to be a cause.
 
A leaking head gasket can over pressurize the cooling system and lead to loss of coolant , the over heating will make matters worse , coolant can be tested for traces of exhaust gas a car radiator specialist will know something about this.
 
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Getting back to Old Rhodie's problem, if there is plenty of seawater (coming from the exhaust I assume) and the heat exchanger is clean, then there must be either a blockage somewhere in the fresh water circulation OR the heat exchanger is undersized OR the water on the freshwater side is being lost by expansion and uncovering some of the tubes in the HEx. A header tank will solve only the last problem but is the easiest and cheapest fix to implement. Searching for "radiator expansion tank" threw up lots of options of which this one http://www.ebay.co.uk/itm/RENAULT-C...39&rk=3&rkt=4&sd=150898784461&#ht_1668wt_1091 looks the cheapest and smallest. But try to have a look at a Clio first to see what size it really is.

As has been said already, talking to Beta would be an idea.
 
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So if the engine is 8 years old, has this been a problem since day one or has it only recently started happening? If it is a recent problem then that rules out the heat exchanger being inadequate, the seawater inlet being too small and the need for a header tank. Perhaps it points to a failing water pump or thermostat or...
 
Beta specify a cooling water flow of 15 litres/min. at 1500 rpm in their manual which covers the 10 to 25 hp engines, and the same for the 28 to 38hp range. I'd think that this flow would be more than adequate for the 13 hp engine.
If you talk to them, they're very likely to ask if you've measured this flow.
My B25 has a 3/4" inlet and has never shown any signs of overheating.
Neither of the two Beta engines I've owned have required an expansion bottle, although there is a tube connection for one.
 
I have a Beta 20hp BD722. Installed from new boat ten years ago.

Had constant overheat problems until I fitted a larger seawater skin fitting up from 15 mm to 25mm. This was despite thinking I had sufficient seawater flow. What you get out the exhaust can be more tied up than when moving due to laminar flow past a slippery hull and whiz zing past the skin fitting. I still get the occasional overheat alarm and put it down to jellyfish etc.
looking down the heat exchanger filler cap, I lose some coolant after a run and have wondered about an expansion bottle to save the coolant as I can see the top of the heat exchanger.
 
OR the water on the freshwater side is being lost by expansion and uncovering some of the tubes in the HEx.

If this is true then why is it not widely reported as a problem on other installations? Presumably the engine is within the recommended angles, in which case if there is coolant loss would it not make more sense to look for where that loss is before spending time/energy/money?

If the coolant has expanded due to heat such that it is pushed out of the lid, surely you will still have coolant still covering the tubes - they will only uncover when it has all cooled down again - ie when it doesn't really matter?
 
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I have a Beta 25 and had overheating problem a couple of years ago but was cured by cleaning out the heat exchanger. Had it again last year but was only the oil presuure alarm going off after a long run and the engine idled. No water overheating and after speaking to Beta who suggested the idle speed needed turing up as after a long run it only idled at about 850rpm. Not done it yet - on my to do list.
 
I have a Beta 25 and had overheating problem a couple of years ago but was cured by cleaning out the heat exchanger. Had it again last year but was only the oil presuure alarm going off after a long run and the engine idled. No water overheating and after speaking to Beta who suggested the idle speed needed turing up as after a long run it only idled at about 850rpm. Not done it yet - on my to do list.
I have installed a new Beta 35 in Jan 2013, had over heating problems right from the start, fortunately I fitted temp gauge supplied by Beta so when the engine first over heated I was aware of the increased heat and stopped the engine just as the alarm went off, I was in the middle of Morecambe bay at 0500 hrs not a breath of wind eventually the wind did fill in a little and I was able to sail into Fleetwood, I phoned Beta who told me it would be the header tank cap and fitting it locks onto it was a faulty one, they sent me a new cap and union with a box of filters and spare fan belt as a complementary gift, I fitted the new parts. And all is fine however I am still not happy about running for any length of time at high revs as the temp does rise above 90c now I guess this is possibly inaccuracies in the gauge or sender but I would like to be able to run flat out if need be without worrying about the temp, I have checked the flow rate from the exhaust and it is around 15 Ltrs per min but it is certainly no more I will be contacting Beta shortly now that I have been running the engine for around. 150 hours. So good luck with your problem, I do know of at least two other new Beta owners who have had faulty caps and fittings, the cap leaks and al the water gets pumped out as the temp increases.
Regards Mike
 
I fitted an expansion tank to my Beta 722 20hp.Before that I had problems with the temperature alarm going off.I replaced the skin fitting with a 25mm one and also both the cap and the temperature sender but it was only after installing the expansion tank that the problems stopped.
 
Hundreds of these manifold heat exchangers are manufactured every year and I am not personally aware of any widespread cooling issues, it it likely to be the operation of the heat exchanger which causes the problem rather than the heat exchanger its self. (Operation meaning blocked tubes, insufficient flow etc rather than something YOU are doing wrong!)

- If you are fitting an expansion bottle, check the pressure caps as the standard 95kPa cap has a single seal which isn't designed to draw back coolant fluid that's lost after venting. For this you will need a cap with a double seal instead. I would ask BETA about this however as I am sure that if an expansion bottle was the solution then they would just be fitting them from new anyway.

- Sea water flow is important, in theory the faster the flow the better performance you'll get however increasing the flow also increases the velocity which can cause erosion of the tubes and tube plate, again I would stick with the guidelines set by BETA on this topic.

- Are you certain that the problem lies around the heat exchanger area and no where else? We know that the system is designed to vent water by a certain amount and that the majority of them fitted to engines work, so could the problem be with the thermostat or with something like an air pocket elsewhere in the system?
 
Hundreds of these manifold heat exchangers are manufactured every year and I am not personally aware of any widespread cooling issues, it it likely to be the operation of the heat exchanger which causes the problem rather than the heat exchanger its self. (Operation meaning blocked tubes, insufficient flow etc rather than something YOU are doing wrong!)

- If you are fitting an expansion bottle, check the pressure caps as the standard 95kPa cap has a single seal which isn't designed to draw back coolant fluid that's lost after venting. For this you will need a cap with a double seal instead. I would ask BETA about this however as I am sure that if an expansion bottle was the solution then they would just be fitting them from new anyway.

- Sea water flow is important, in theory the faster the flow the better performance you'll get however increasing the flow also increases the velocity which can cause erosion of the tubes and tube plate, again I would stick with the guidelines set by BETA on this topic.

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Thanks for that - I did get the expansion bottle etc. which is now an option on this engine from BETA, as I described earlier - but too big.
I expect the H/Es fitted to most engines won't have the bow cocked up so that the coolant in the thermostat cover is above the filler cap ?

Thanks 30boat, you cheer me up and I have now found contacts for a motor cycle tank to try.
ken
 
Thanks for that - I did get the expansion bottle etc. which is now an option on this engine from BETA, as I described earlier - but too big.
I expect the H/Es fitted to most engines won't have the bow cocked up so that the coolant in the thermostat cover is above the filler cap ?

Thanks 30boat, you cheer me up and I have now found contacts for a motor cycle tank to try.
ken
why does the tank have to be in the engine bay, it would be ok in an adjacent locker
 
.I expect the H/Es fitted to most engines won't have the bow cocked up so that the coolant in the thermostat cover is above the filler cap ?

Many sailboat engines are installed with the front end tilted up. Mine is 10 deg. Beta specify up to 15 deg. maximum either way.
I don't think that it will be the cause of your problem.
 
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