RYA Diesel Course unhelpful. What shall I ask engineer to teach me on a Yanmar

tudorsailor

tudorsailor

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In the past I have completed an RYA Diesel Course and it was one of the most unfulfilling days I have spent. Generally, I have a local engineer service the engine as I try to spend time on board sailing rather than maintaining. So I am lacking basic engine skills

We are considering sailing further afield - the ARC. So I would like to learn more about the engine. I wonder of it would be more useful to get a mechanic to show me things on my engine rather than do another course. Would others agree? If you do, what skills should I get the engineer to teach me? Changing the fuel filter and changing the Racor seem an obvious start. What else would be essential?

Alternatively, can anyone recommend a course that has hands on teaching on a Yanmar 4JH23-TE 88HP?

Thanks

TudorSailor
 
Bleeding the fuel system that would come with changing filters. Changing an alternator or water pump belt. Changing an impellor. You are correct in getting some tuition relevant to your particular engine
 
Checking oil level/topping up
checking coolant level/topping up
Changing seawater impellor
Changing oil and fuel filters
Bleeding the fuel system
Changing the aux belt
Checking gearbox oil level
Replacing fuel lift pump
Fuses, relays, etc. (where they are, what they do, how to replace).
Where things like oil pressure switch and, thermostat, and coolant temp guage are.
 
All the suggested routines should have been covered on the RYA diesel course. I'd wonder what your course covered if it didn't do those! And diesels are pretty generic in their basic needs; which engine you have shouldn't matter for the things mentioned so far.

I speak as a person with minimal mechanical skills, but the RYA course gave my wife and I the confidence to strip down the cylinder head on our Volvo (with a bit of help from a more mechanically inclined brother)!
 
I heard a bout a man the other day who learnt to be a motor mechanic at an early age . Before starting he was told to take a Diesel engine to bits and reassemble it again . On the basis that was the right way to learn . Perhaps you should get an old one from a scrap yard and spend the winter months doing the same perhaps even refurbishing it to a working condition . Learning on the job is the best way even if you fail
tudorsailor said:
In the past I have completed an RYA Diesel Course and it was one of the most unfulfilling days I have spent. Generally, I have a local engineer service the engine as I try to spend time on board sailing rather than maintaining. So I am lacking basic engine skills

We are considering sailing further afield - the ARC. So I would like to learn more about the engine. I wonder of it would be more useful to get a mechanic to show me things on my engine rather than do another course. Would others agree? If you do, what skills should I get the engineer to teach me? Changing the fuel filter and changing the Racor seem an obvious start. What else would be essential?

Alternatively, can anyone recommend a course that has hands on teaching on a Yanmar 4JH23-TE 88HP?

Thanks

TudorSailor
Click to expand...
 
tudorsailor said:
..............

Alternatively, can anyone recommend a course that has hands on teaching on a Yanmar 4JH23-TE 88HP?

Thanks

TudorSailor
Click to expand...

Do you mean 4JH2-DTE, which is my engine, and rated 88HP? If so you need to learn how to change the impeller, and have the right tool to get the old one out, and actually practice doing it. The reason is that on this particular engine the raw water pump containing the impeller is mounted on the port side facing aft with the starter motor obstructing access with anything as big as the Jabsco impeller removal tool.
 
How to check the voltage over the glow plugs & tell if it is the glow relay or the plugs themselves
How to use a digital multimeter
How to bypass the electrics & jump start the engine straight from the battery with jump leads thus cutting out all the minefield of wiring
 
I went on a RYA Diesel Course and was surprised that they did not show how to bleed a diesel. On the course were a couple of ladies and I felt the instructor should have gone through what tools to have, especially small 1/4 drive sockets which are invaluable when blleding the injector pump which is in an inaccessible place.
I would also say that you must learn to change the Impeller. My last boat had an excellent Yanmar engine and the plate for the Impeller pump could just about be seen and once the plate was off to look at the impeller itself required a mirror. There was no room to get an impeller puller in (or pliers) If I had believed the service schedule from 60 hours before where it said that the impeller was "serviceable" I would have ended up a statistic on the Lifeboat Call Out List.
Because I could not get it out I asked a Marine Engineer to remove the pump, which involved in stripping part of the engine, took him 30 min and when the impeller was examined it was falling apart.
I only felt that the impeller had not been changed as a boatyard will never miss an opportunity to take profit out of a sale, but perhaps the mechanic was on a fixed price and did not want to waste an hour fitting an impeller for which he would not get paid.
So as I have had 2 impellers fail while out at sea it is perhaps one of the most essential things you can learn.
 
It's an excellent idea to get someone to talk you through the features of your own engine, on your own boat. Ideally, you need someone with specific Yanmar experience, and perhaps combine it with a service visit.
 
Norman_E said:
Do you mean 4JH2-DTE, which is my engine, and rated 88HP? If so you need to learn how to change the impeller, and have the right tool to get the old one out, and actually practice doing it. The reason is that on this particular engine the raw water pump containing the impeller is mounted on the port side facing aft with the starter motor obstructing access with anything as big as the Jabsco impeller removal tool.
Click to expand...

This is one thing that I can do having changed the pump cover to a Speedseal. Speedseal also supplies an impeller removing tool.

TS
 
have you looked on youtube you will find plenty of things to watch not just for your engine but in general mechanical practices
 
Having just been on a one day RYA diesel course with Sailtrain I can only think that the OP was unlucky in his instructor as our day was packed with basic theory and hands on work on a simple twin engine and thoroughly useful as is the 'RYA Diesel Engine Handbook'.It may be that the Yanmar 4 series has significant special features although with a 2GM20 I found it easy to extrapolate to my particular layout where access is in fact the trickiest element.I don't know what's readily available for the 4 series but the 'Yanmar Workshop Manual' for the 2/3 series (downloaded) goes into very clear detail on the parts requiring service and at A4 with large diagrams and english-only text is far more useful to deploy than the cramped multi language owners manual.
 
My own perception is that the RYA course teaches you a lot about bits that don't usually break. Not to knock it, but my struggles have been with things like throttle cables (some smartass will now tell me a diesel doesn't have a throttle), alternators, gearboxes, felxible couplings, stern glands and all the other bits that vary idiosyncratically from boat to boat. Good to know how your engine works though.
 
tudorsailor said:
In the past I have completed an RYA Diesel Course and it was one of the most unfulfilling days I have spent. Generally, I have a local engineer service the engine as I try to spend time on board sailing rather than maintaining. So I am lacking basic engine skills

We are considering sailing further afield - the ARC. So I would like to learn more about the engine. I wonder of it would be more useful to get a mechanic to show me things on my engine rather than do another course. Would others agree? If you do, what skills should I get the engineer to teach me? Changing the fuel filter and changing the Racor seem an obvious start. What else would be essential?

Alternatively, can anyone recommend a course that has hands on teaching on a Yanmar 4JH23-TE 88HP?

Thanks

TudorSailor
Click to expand...

You cannot seriously be thinking of hiring someone to teach you how to change an oil filter! Its common sense. Just do it.
 
tudorsailor said:
Alternatively, can anyone recommend a course that has hands on teaching on a Yanmar 4JH23-TE 88HP?
Click to expand...


It'll probably be hard to take everything in at once if you did get a mechanic to teach you. Chances are a good mechanic is probably not a good teacher of novices. Try practising with simple things yourself, like changing the fuel filters/impellor/oil & oil filter.

I don't know about the TE, but the 4JH-2BE is very good at bleeding itself as long as the secondary filter is pretty full when you start the engine(the air goes down the return pipe to the tank) so I've got incredibly lazy. Just make sure you've run it long enough to be sure before depending upon it.

You can find pretty comprehensive Yanmar manuals on-line.

As others have mentioned, the Yanmar engineer who positioned the impellor had dreams of going off to join a circus as a contortionist and set up the engine so he could practice in his day job. A trick I've found is that you can screw a bolt of the right size into the old impellor, then pull.

Edit: And remember to close the seacock when you're changing the impellor. :)
 
Last edited:
Jim@sea said:
I went on a RYA Diesel Course and was surprised that they did not show how to bleed a diesel. On the course were a couple of ladies and I felt the instructor should have gone through what tools to have, especially small 1/4 drive sockets which are invaluable when blleding the injector pump which is in an inaccessible place.
I would also say that you must learn to change the Impeller. My last boat had an excellent Yanmar engine and the plate for the Impeller pump could just about be seen and once the plate was off to look at the impeller itself required a mirror. There was no room to get an impeller puller in (or pliers) If I had believed the service schedule from 60 hours before where it said that the impeller was "serviceable" I would have ended up a statistic on the Lifeboat Call Out List.
Because I could not get it out I asked a Marine Engineer to remove the pump, which involved in stripping part of the engine, took him 30 min and when the impeller was examined it was falling apart.
I only felt that the impeller had not been changed as a boatyard will never miss an opportunity to take profit out of a sale, but perhaps the mechanic was on a fixed price and did not want to waste an hour fitting an impeller for which he would not get paid.
So as I have had 2 impellers fail while out at sea it is perhaps one of the most essential things you can learn.
Click to expand...
That is why I did NOT choose a Yanmar when I re-engined a few years ago!
 
I did the one day but felt I was not ready to do a brand new engine on my own. So Last year paid an engineer to watch me do the service and talk me through bits I was unsure about. This year I've done it all myself.
 
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