J2 - new owner - starting on diesel

[Mike Adams]

I have just bought a boat fitted with a J2 Kelvin and hydralic drive. The current owner is only able to start it on petrol by hand as the starter moter has slipped/will not engage. The starter motor seems very old pre-engaged design.I suspect the starter teeth are also shot. I cannot find anything about electric starting in the books I have been given.

My questions are - When would you normally be able to start on diesel alone? I assumed from cold some sort of preheating would be need either in the intake or glowplugs. I really don't want to have to resort to petrol unless I have to.

It is possible to fit a more modern say co-axial CA45 starter - any recommendations

Thanks

Mike

 

[RLWP]

Can you post some pictures of the starter? 

Richard

[Mike Adams]

This is not the actual starter but the same type. I had one of these in an old dorman 3LB many years ago.

[RLWP]

We can get those reconditioned

Richard

[Mike Adams]

Thanks Richard

I am hoping to get the boat home at the weekend so I will take it out then.

Mike

[BEngo]

The Starter motor should be an axial ( not pre-engaged)  CAV BS5 12 (or 24)P101 depending on voltage.  Your piccy looks right. They are common and any good auto eleccy should be able to recondition one. The pinion is a bronze one to go with the cast iron flywheel teeth and somewhere I have the workshop manual as a pdf should you need it.

When you re-fit the motor the clearance between the rear of the flywheel and the front face of the starter pinion should be 9/64 in. If it is too small the armature does not get full power because it cannot move axially to trigger the main internal contactor.

Getting a J to start on diesel from cold without heaters ( or Easy Start )   is hard.  Even the cold start version with special rocking horse poo  cylinder heads and no plugs is a bugger when it is cold.The K and L will but the J  combustion space is much smaller so the air cools more than in the bigger model.  A thermostart is the usual solution though I just use petrol. Dave Moore has posted pictures of the set up in Resolute somewhere on this forum this year.Why are you not keen on petrol?  It makes starting a doddle. Mine goes first piston over even in January. Champion K 97F plugs are the canines cojones if you are still on 18mm plugs. For 14 mm holes try a Lodge BL 14.

N

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Edited October 24, 2017 by BEngo
mention the cold starting versions

[Mike Adams]

Thanks for the information. I am not keen on petrol as I was once blown out of a motor boat when a fuel leak on a petrol powered cruiser went up. OK it was a hot day but petrol leaked out somewhere and when the stater engaged the whole lot went off! My understanding is that the thermostart is just an electric heater in the inlet manifold? Can I assume there is no possibility of fitting glow plugs to the engine? The engine number is 18763

I will have a look at the pinion but I thought it was steel. From your comments its not a shrunk on ring gear. I would have though a cast iron one wouldn't last very long

Mike

[koukouvagia]

15 minutes ago, Mike Adams said:

  My understanding is that the thermostart is just an electric heater in the inlet manifold? Can I assume there is no possibility of fitting glow plugs to the engine?  

It's a bit more than that because they're connected to a diesel supply, so burning diesel is sucked into the air intake.  They are very effective.  

[BEngo]

A thermostart burns diesel in the inlet manifold, so it needs a power supply for the igniting coil and a small diesel supply.   I suppose you could put a couple of heater plugs in the manifold above the inlet ports but there is no where to put one in the cylinder head unless you can replace the petrol combustion chamber and the starting valve.  Even then I would be wary of the effects on the diesel combustion in  the venturi and would not want to lose the ability to hand start.

A factory  standard small or large  flywheel has no teeth.  The electric start ones have teeth cast and machined into the rear edge. Some may have been modified to take a shrunk on ring gear.   A steel pinion should never be used with cast iron as the wear will be on the cast iron rather than the (replaceable) pinion. If the starter is otherwise OK a pinion change is a 15 minute job involving one nut and associated split pin.

If  you have  the red book no18 "Instructions for running and repairing " or similar it describes how to do an electric start. It basically is identical to a hand start  but uses the starter to swing the engine over.

I can understand your concern about petrol. I suppose I have just developed habits to mitigate the risks. 

N

[David Mack]

16 hours ago, Mike Adams said:

I have just bought a boat fitted with a J2 Kelvin and hydralic drive.

So which boat have you bought, Mike?

[Mike Adams]

Hi Dave

It's called MSC frodsham  - a replica MSC tug - very much a project like yours

Regards

Mike

[KroSha]

I have a J2 with a similar starter motor. The sticker on it points to https://www.startermotorsalternators.com/

You can have a pre-heater fitted to the top of the inlet, koukouvagia fitted one on my engine for the previous owner. I've never used it and I think it's burnt out, but the theory is sound.

[dave moore]

I’ll happily provide glo plug details if required, we fitted 2 on Resolute by grazing threaded brass collars on to the air intake. We also had to provide power and a diesel supply to them. Many years later, they are still performing well. Dick Goble, the Kelvin guru, gave lots of helpful advice. We fitted them to get round magneto issues and like the op I was less happy with petrol start on safety grounds.

While on the petrol subject, I was advised by one of the Gardner family that old fashioned leaded petrol would be better suited to use for starting, which we found to be true years ago. I was fortunate to have a local garage that sold it. Just a thought.....

[BEngo]

I can see no reason why leaded petrol might be any better than unleaded provided both are fresh.  High octane peaded fuel waz not available easily when the J and K were designed and the petrol compression ratio is so low that it is not needed anyway.  Diesel is always unleaded so there is no benefit to the valve seats from leaded starting fuel.

There may have been other additives in the leaded fuel which made it keep better, but I don't think so.  If anything my experience is that modern petrol lasts as well or better in all sorts of small machinery.

N

[koukouvagia]

This is the homemade  arrangement I fixed on my Kelvin.  I drilled and tapped the air intake elbow to take the thermostart.  (Tip use metric thread, because metric thermostarts are much easier to locate).  I added a warning light to show when the thermostart is on.  I learnt the hardway, several times, that they burn out if left on and they are quite pricey to replace.

 

Edited October 28, 2017 by koukouvagia

[dave moore]

Bengo, I’m a painter, not an engineer, as you probably know. I can only say, hand on heart, that the leaded petrol we used for a while certainly made starting easier when we had the petrol start, Who was I to ignore advice from one of the illustrious engine manufacturing family? I appreciate your reasoning, makes sense to me, but I can only add my first hand experience. Dave

[magnetman]

I had a look at MSC Frodsham thinking i might buy it a couple of weeks ago. The condition was quite shocking but hull (6mm steel) seemed good. I'm glad someone bought it as its a nice boat but what a big project ! I think the wooden part of the cabin has got to go but maybe it can be saved.

 

Iirc the J2 has a thermostart on it.

 

Its a very unusual boat. Good luck with it - specially with actually getting into the engine room !!

 

 

Edited October 29, 2017 by magnetman

[magnetman]

Frodsham when I passed it on the river Wey this summer.

 

Edited October 29, 2017 by magnetman

[Mike Adams]

I moved the Frodsham to my end on garden on the Basingstoke  on Saturday. It is quite a project but the kelvin and the hydraulic drive worked faultlessly. I think the cabin is saveable and 2 days of heating, cleaning have made a remarkable difference but a long way to go. Despite its appearance it only draws 2'7".

 

[Markinaboat]

we had a thermostart on our K3. Drop of diesel in the chamber then a blow torch up the intake until there was a flash. Always started but with a starter motor as I couldn't turn the bugger over by hand!