HONDA BD-15D OUTBOARD - HELP NEEDED WITH COOLANT BLOCKAGE

[stevevp]

Can anyone please recommend someone to sort out a blockage in the cooling system on my Honda BD-15D outboard. I've repeatedly cleared the outlet hole but the water just stops again after a few seconds. I'm on the Pennyland Marina, Milton Keynes (MK15).

 

Many thanks.

[rusty69]

Are you sure it doesn't just need a new impeller? 

Edited August 18, 2023 by rusty69

[Alan de Enfield]

5 minutes ago, rusty69 said:

Are you sure it doesn't just need a new impeller? 

 

It does sound more like a impeller problem than a blockage.

 

56 minutes ago, stevevp said:

Many thanks.

 

You do check the impeller regularly and change it (ideally) annually don't you ?

 

Have you started the engine with the prop out of the water ?

Edited August 18, 2023 by Alan de Enfield

[stevevp]

Thanks for your replies.

 

The impeller was changed about 18 months ago and, for various reasons, the engine has been run for less than 10 hours since - the boat has not moved at all this year because of travel and my failure to sort out the coolant issue.

 

I've not started the engine with the prop out of the water - I've assumed I shouldn't.

[Alan de Enfield]

18 minutes ago, stevevp said:

Thanks for your replies.

 

The impeller was changed about 18 months ago and, for various reasons, the engine has been run for less than 10 hours since - the boat has not moved at all this year because of travel and my failure to sort out the coolant issue.

 

I've not started the engine with the prop out of the water - I've assumed I shouldn't.

 

If the engine has not been started for some time, the rubber of the impeller vanes 'welds itseld' to the housing, when you do start the engine the vanes are torn off the impeller.

Thus is why a boat that is (say) Winteriesed and will not be used for a few months, must, have the impeller removed and stored in oil.

[magnetman]

It could be a buildup of limescale and general junk. Rodding out with a cable tie or a piece of plastic covered electrical wire can help. 

 

If it keeps happening then perhaps more serious but these outboards do often get blocked outlets. 

 

It is just an indicator not the actual cooling water coming out of the hole. 

 

Does the outboard overheat? There should be a temperature lamp on the remote control (if it is remote control)

 

If the impeller is okay the engine will run fine and not overheat even if the indicator flow of water is not coming out because most of the cooling water goes back into the water via the exhaust system which is below the waterline. 

 

 

 

Edited August 18, 2023 by magnetman
Typo

[Alan de Enfield]

 

I was always told by Outboard mechanics never to push anything up the tell-tale as 

a) On a small out the pipe is so small that you cannot fit a nice soft  cable tie.

b) Anything that is 'stiff enough' (a piece of wire) will be too stiff to follow the contours/routing of the pipe and will puncture the soft, flexible pipe meaning you now have water squirting about under the hood - not a good idea on a petrol / spark powered engine.

 

To clean it out, disconnect and remove the length of pipe and the tell tail fitting, try to blow thru, if it is not clear then take the hose off the fitting and check if the tell tail is clear.

If you cannot clear the hose then it is only 'pennies' to get a new length of small bore hose.

 

 

If the impellor has 'shredded' then you must try and find all of the bits otherwise they can block the water channels inside the engine, then you will have overheating problems.

 

Outboard engine need much more looking after than a big inboard diesel engine. They are not fit-and-forget.

[magnetman]

On these Hondas a cable tie or a piece of electrical wire does fit. 

 

I was given this advice by a bloke in Henley who runs several day hire boats with Honda 15 outboards on them. They regularly get blocked up and while it is not a problem per se it does mean you don't know if the impeller is alright until you get an overheating situation. 

 

 

It worked for my Honda 10 which had exactly this problem when I bought it. 

 

Rigid coat hanger wire not a good idea. 

 

 

[stevevp]

Again, thank you all for your advice, I do appreciate it. I'm sadly out of my depth with all this!

 

I will check to see if there is a temperature warning light on the remote - I thought there was only oil pressure - either way, it's almost impossible to see in daylight. Is the warning light the only way to confirm the engine is cooling without the tell-tale? If I run the engine on the mooring, how long would it take to overheat?

 

One person who looked at the boat has said the pipe is blocked as he can't blow through it. He suggests blowing it through with a compressor but I'm concerned that it will burst something.

 

I'd rather pay for an expert eg to check the impeller if I can find one. One thing that doesn't help is the location of my mooring which necessitates getting into the water to do any work, albeit at the shallow end of the basin!

 

 

[Alan de Enfield]

6 minutes ago, stevevp said:

Again, thank you all for your advice, I do appreciate it. I'm sadly out of my depth with all this!

 

I will check to see if there is a temperature warning light on the remote - I thought there was only oil pressure - either way, it's almost impossible to see in daylight. Is the warning light the only way to confirm the engine is cooling without the tell-tale? If I run the engine on the mooring, how long would it take to overheat?

 

One person who looked at the boat has said the pipe is blocked as he can't blow through it. He suggests blowing it through with a compressor but I'm concerned that it will burst something.

 

I'd rather pay for an expert eg to check the impeller if I can find one. One thing that doesn't help is the location of my mooring which necessitates getting into the water to do any work, albeit at the shallow end of the basin!

 

 

 

 

I wouldn't expect to be able to 'blow thru' it as it is attached to the engine,

Try disconnecting the tell-tail pipe at the engine end and (with the lid off) start the engine and see if water is FORCEFULLY being ejected from where the hose connects, if it is then it is probably that the hose is blocked, if there is no, or very little, water being ejected then the pump is at fault.

 

Once the hose is disconnected from the engine it should be possible to blow-thru it.

If you can get it clear, why does it keep getting blocked, -  try and find out what is blocking it,

 

If it is the hose blockage, then the simplest thing is to replace the hose, as if it is (say) limescale then you'll not get it all out of the hose and the 'old'. hose will quickly block up again.

[magnetman]

49 minutes ago, stevevp said:

One thing that doesn't help is the location of my mooring which necessitates getting into the water to do any work, albeit at the shallow end of the basin!

 

 

This is rather odd because the outboard can be tilted out of the water if it is on the back of the boat.

 

Is this outboard mounted in some sort of internal 'well' where you can't lift it up and get the leg out of the water?

 

If major work is required the best thing is to get the motor off the boat rather than getting in the water to deal with it.

 

They are heavy though. I think the 15 is getting on for 50kg.

 

 

I think it is unlikely there is a problem with the impeller. Much more likely to be a blockage of the indicator 'tell tale' water oulet because this is such a common problem with that particular outboard motor.

 

On the remote control there is an oil lamp and an overheating lamp.

 

I'm not sure as it never happened on my outboard but I think the engine will cut out if either of these things are outside of operational limits. Honda are very good at adding safety systems to their products.

 

I'll have a look  at my BF10D in the morning. I'm not convinced that these outboards have a flexible pipe to the tell tale. I tnink it might be straight from the engine block.

 

 

 

 

 

 

[Alan de Enfield]

24 minutes ago, magnetman said:

I'm not convinced that these outboards have a flexible pipe to the tell tale. I tnink it might be straight from the engine block.

 

 

My outboard days are a few years behind me now, (I only have my little Honda BF20 on my tender now) and things do move on so maybe it is a rigid fixing, but, I'd have thought not, as vibrations would break it off.

[stevevp]

Thanks for your reply.

 

The engine does tilt but when I pull the boat backwards into my u-shaped mooring, it bottoms out before the (raised) engine is over dry land. I can attest to the canal being a fairly unpleasant place to be standing up in!

 

I've checked and I do have a temperature warning light. Perhaps I should let the engine run and see if it cuts out. I guess 10 minutes would be more than enough if it was going to overheat? Grateful advice on this.

 

I'm really not mechanically competent to work on the engine myself and have a history of breaking things when I try (not this engine). I'm also not able to lift the engine off the boat. The last time it came off it was a two man job and I wasn't either of them!

Edited August 18, 2023 by stevevp

[stevevp]

Just a quick bump on this in case any one knows of someone in the Milton Keynes area who can help with this.

 

I've just run the engine for 10 minutes with no overheating warning. The water came out the top vent for about a minute and then stopped. Poking a paperclip in the vent to clear it didn't help.

 

Many thanks.

[Alan de Enfield]

1 minute ago, stevevp said:

Just a quick bump on this in case any one knows of someone in the Milton Keynes area who can help with this.

 

I've just run the engine for 10 minutes with no overheating warning. The water came out the top vent for about a minute and then stopped. Poking a paperclip in the vent to clear it didn't help.

 

Many thanks.

 

Have you done as I suggested (remove the pipe from where it connects to the engine - start engine, if water squirts out then the pump is OK and the pipe is blocked. If it doesn't squirt out then the pump is not working)

 

It's a quick and simple test that will isolate the problem.

[stevevp]

Thanks for your reply but I wouldn't know how to access the pipe at the engine end. It's not question of lazyness but mechanical incompetence and a tendency to break things, however careful and wellmeaning! I'd rather pay someone to do it properly.

 

PS. I don't have a workshop manual and the user manual doesn't have diagrams.

[Alan de Enfield]

 

20 minutes ago, stevevp said:

I wouldn't know how to access the pipe at the engine end.

 

 

Find the pipe attached to the 'tell-tale' spigot and follow it back to where it attaches to the the engine, it wont be very far away.

 

If it is a rubber pipe it will probably be attached onto the engine with a jubilee clip, loosen the clip and pull off the pipe.

 

If it is a rigid metal pipe it may have a metal nut on the end , loosen nut and ease pipe away from the engine.

 

Run engine and see what happens.

 

 

 

You are going to need to become a little but more 'self supporting' and able to do simple work or boating will become a very expensive hobby.

 

A boat yard will typically be charging £60 + VAT per hour with a minimum of 1 hour charge-out. So for a simple job that will take you 10 minutes you'll be paying someone £72 to do it for you.

 

Have a look on the Honda website - they list all of the manuals (owners manual and workshop manuals) which you can download for free.

 

Here is the owners manual (which you may have) see page 65

 

32ZY06380_web.pdf (honda.co.jp)

 

Have you checked the water intake is not blocked ?

 

Now find and down load the workshop manual.

 

 

 

 

 

Edited August 21, 2023 by Alan de Enfield

[stevevp]

Alain,

 

Many thanks for your message, I do appreciate the effort.

 

On the pipe, it is rubber and I can barely reach the top end. I guess access to the bottom end requires something to be taken off? Whilst I do have the owners manual, it does not cover this. I can't find the list you mention to the workshop manual on the honda uk or jp websites. I have searched.

 

I appreciate the need to be self-sufficient but I'm happy to pay someone to fix it if they know what they are doing. It's much cheaper than me breaking something!

 

As far as I can see, with the engine tilted, the intake is not bloked although there was quite a lot of algae/weed on it which I allowed to dry and have brushed off. As mentioned, there is some initial flow of water from the check hole and the engine did not overheat after 10 minutes running.

 

Steve

[Alan de Enfield]

19 minutes ago, stevevp said:

As mentioned, there is some initial flow of water from the check hole and the engine did not overheat after 10 minutes running.

 

It could be partially blocked and when it is standing an amount seeps into the leg thru the inlet which is then 'used up' once the engine starts, Running the engine at tickover will not overheat the engine in a 'few minutes'.

 

This is one of the legs on my Catamaran which is almost totally blocked with 'limpetty things' and weed and although the engine was running hot it was not at the overheating stage.

Try and clear your inlet of all obstructions and try and see inside the 'grill'.

 

You really should try and get to the bottom of why the tell-tale is not working, as although the water MAY be circulating today, when it does fail you will not know and you'll end up with a siezed up engine.

 

Pictures were about 6 months after the last lift out and 2000+ miles at Sea.

 

You can just see the water inlet holes - some of them 100% blocked.

 

Edited August 21, 2023 by Alan de Enfield

[stevevp]

Mine is about 9999% cleaner than yours! It's fairly clean externally including the grilles, I just don't know what's got inside. I'll try and get the boat turned round and have a closer look.

[Mad Harold]

Nylon strimmer cord is best for clearing the water outlet.

Depending where you are, you can get little critters up the water system and they can grow and breed.

[stevevp]

6 minutes ago, Mad Harold said:

Nylon strimmer cord is best for clearing the water outlet.

Depending where you are, you can get little critters up the water system and they can grow and breed.

Thanks, from the top or the bottom?

[Mad Harold]

14 hours ago, stevevp said:

Thanks, from the top or the bottom?

From the top.

On my outboard (Tohatsu) I needed to insert about 18 inches whatever that is in foreign capurtallers.

[Alan de Enfield]

4 minutes ago, Mad Harold said:

From the top.

On my outboard (Tohatsu) I needed to insert about 18 inches whatever that is in foreign capurtallers.

 

Did you have to split the leg off from the power head to get access ?

[Mad Harold]

2 minutes ago, Alan de Enfield said:

 

Did you have to split the leg off from the power head to get access ?

No, simply pushed the strimmer cord into the tell tale untill I felt resistance, and pulled back and forth a few times.

I did have to do this twice, as it didn't work the first time.