Lister JP3 - What to look for

[John Barnet]

Thinking of buying a boat with Lister JP3 plant.

Any advice on what to look out for would be greatly appreciated.

[bag 'o' bones]

Thinking of buying a boat with Lister JP3 plant.

Any advice on what to look out for would be greatly appreciated.

 

Take someone with you who knows what there talking about even if you have to pay them.

 

I probally know more than your average DIY mechanic when it comes to messing about with cars but old fashioned engines are a different kettle of fish as even very worn engines can can start ok and 'sound alright' to the untrained eye (basing that on my experience of working on a dumper truck's Petter AVA1)

 

Just a thought will probally save you money in the long run.

[Proper Job]

Assessing the condition of any engine is similar irrespective of age.

 

The fact that its a JP means that its in an engine room so access around it should be a lot easier than a modern unit hidden in a box at the back of the boat.

 

How easy is it to start (from cold)? I set mine to about 1/4 throttle and 2 - 3 revolutions of the engine on the starter and its away.

 

Listen for obvious rattles, knocks etc. When cold, they tend to thump a bit, but should quieten down a bit once warm (if it ever does get warm).

 

How much smoke is coming out of the exhaust? What colour is it?

 

What is the general external condition? oil leaks? etc

 

Where are you? If you know anyone locally with a JP (2 or 3) talk to them, listen to their engine.

 

A JP3 is a good robust engine and if looked after (normal maintenance), will last for many years.

 

If your in the Oxford area, your welcome to come and have a look at mine. Another good contact is Mark Paris - BSC examiner and mobile engineer (07860 711003). He's a JP man.

Edited January 19, 2009 by Proper Job

[John Barnet]

Assessing the condition of any engine is similar irrespective of age.

 

The fact that its a JP means that its in an engine room so access around it should be a lot easier than a modern unit hidden in a box at the back of the boat.

 

How easy is it to start (from cold)? I set mine to about 1/4 throttle and 2 - 3 revolutions of the engine on the starter and its away.

 

Listen for obvious rattles, knocks etc. When cold, they tend to thump a bit, but should quieten down a bit once warm (if it ever does get warm).

 

How much smoke is coming out of the exhaust? What colour is it?

 

What is the general external condition? oil leaks? etc

 

Where are you? If you know anyone locally with a JP (2 or 3) talk to them, listen to their engine.

 

A JP3 is a good robust engine and if looked after (normal maintenance), will last for many years.

 

If your in the Oxford area, your welcome to come and have a look at mine. Another good contact is Mark Paris - BSC examiner and mobile engineer (07860 711003). He's a JP man.

 

Hello Steve

 

Thanks for the reply. I have viewed the boat and are interested. However the engine would not start at the time. The owner, who wasn't present, seemed genuinely suprised. It was agreed the battery was to blame.

I intend going back once this is sorted.

 

The enigne room is very tidy, the bilges are also clean. A little bit of oil on the side of the engine, didn't really look too hard to see where it may have come from, but will when i go back.

 

The overall state of the business end looked good, the boat has the feel of one that has been looked after.

 

There was a box of bits stowed at the front of the boat including piston, con-rods and a set of valves. Not sure what thats about, but looked like spare bits.

 

Does your engine start with full compresion? The owner of this one says he normally turns the engine will the compression lever up then pushes down one it have fired. He also suggest, as the boat had been standing foe while we may need to prime the fuel pump.

 

The exhaust outlet and extention pipes are very sootie, though seem to be in the main 'dry soot'.

 

If i go any futher I will contact your suggestions. would also appreciate a view of yours as a reference point.

 

Thanks so far

[mykaskin]

Does your engine start with full compresion? The owner of this one says he normally turns the engine will the compression lever up then pushes down one it have fired. He also suggest, as the boat had been standing foe while we may need to prime the fuel pump.

 

The exhaust outlet and extention pipes are very sootie, though seem to be in the main 'dry soot'.

 

Hi John,

 

As a new owner of a JP2 I can't really say anything with much authority, but what I've found out is the following:

 

First, mine is hand-start only. It would be worth checking if you can hand start the engine in this boat, as is it is handy if you have flat batteries. However it took me and my Dad about one hour to start it after being left for 2 weeks over Xmas, and only a burning oil rag in front of the air intake got it going in the end!

 

Hand turning the engine when cold is quite hard, and needs a lot of work to get it moving fast. Don't expect it to fire the first few compressions, but the engine gets easier to turn after a while and it should have enough speed to get over two compressions after which it usually starts.

 

On the JP series there are two valves in the side of the engine which control compression ratio - these need to be fully screwed in and ensure they are well seated otherwise the cylinders won't get compression (they blow though the screws).

 

You should be able to start the engine with the compression levers down if using an electric start, however if the battery is low/flat then letting it spin to speed first will help. If it doesn't start from an electric motor then it doesn't bode well, though it might be a fuel problem.

 

There is a load of soot stuck in the exhaust of my JP2 also. When the engine is running up to throttle speed the regulator opens fully and causes plenty of black smoke, which should come clean once the engine is up to speed - assuming its upto temp and working well. Running flat out under a good load for an hour should get the engine to a nice temp, otherwise even with the water turned off it takes ages for the engine to get to temp.

 

When running hard, and up to temp my JP2 seems to seep oil from a few joins in the engine. I know mine needs a service, and may need the oil seals replacing.

 

 

Hope that helps,

 

Mike

[Timleech]

Hi John,

 

As a new owner of a JP2 I can't really say anything with much authority, but what I've found out is the following:

 

 

There is a load of soot stuck in the exhaust of my JP2 also. When the engine is running up to throttle speed the regulator opens fully and causes plenty of black smoke, which should come clean once the engine is up to speed - assuming its upto temp and working well. Running flat out under a good load for an hour should get the engine to a nice temp, otherwise even with the water turned off it takes ages for the engine to get to temp.

 

 

 

Mike

 

 

There should be a weighted stop on the end of the fuel pump control rod, you lift it to give extra fuel for starting, it drops under its own weight once the engine picks up speed.

If your engine doesn't have this, it's worthwhile fitting one as it should stop that heavy smoke.

If you already have such a stop and there's still heavy smoke when opening the throttle, get your injectors checked.

 

Tim

[Proper Job]

Hello Steve

 

Thanks for the reply. I have viewed the boat and are interested. However the engine would not start at the time. The owner, who wasn't present, seemed genuinely suprised. It was agreed the battery was to blame.

I intend going back once this is sorted.

 

The enigne room is very tidy, the bilges are also clean. A little bit of oil on the side of the engine, didn't really look too hard to see where it may have come from, but will when i go back.

 

The overall state of the business end looked good, the boat has the feel of one that has been looked after.

 

There was a box of bits stowed at the front of the boat including piston, con-rods and a set of valves. Not sure what thats about, but looked like spare bits.

 

Does your engine start with full compresion? The owner of this one says he normally turns the engine will the compression lever up then pushes down one it have fired. He also suggest, as the boat had been standing foe while we may need to prime the fuel pump.

 

The exhaust outlet and extention pipes are very sootie, though seem to be in the main 'dry soot'.

 

If i go any futher I will contact your suggestions. would also appreciate a view of yours as a reference point.

 

Thanks so far

John

 

I'm now racking my brain. Are you sure its a JP Lister? I've never come across one with a decompresser unless it is hand start only.

 

JP series engines have a high compression/low compression system. On the side of the head are 'knobs' that screw in/out. You start the engine on high compression (knobs screwed in) and once the engine is warm and working hard, you can unscrew the knobs to lower the compression and (theoretically) reduce the strain/wear and tear on the engine.

 

There are differing opinions about the high/low compression running. I always run mine on high compression. When on canals, the engine never works that hard and is rarely above 500 - 600 rpm. Running the engine lightly loaded on low compression can lead to combustion problems and 'lumpy' tick over.

 

Likewise, all of the JP's I know have day tanks. The fuel pump should be gravity fed, There is no lift pump.

 

Have you got any piccie's or links to piccie's? (PM me if necessary).

 

 

Edited to add:

The oil down the side of the engine may not be an oil leak. The greasers from the rocker covers often squeeze a bit out around the sides. The grease falls down between the cylinder heads and when warm, runs down the side of the engine. You could spend hours looking for that non existant oil leak

 

When running hard, and up to temp my JP2 seems to seep oil from a few joins in the engine. I know mine needs a service, and may need the oil seals replacing.

Mike

 

see my reply above about the greasers and phantom oil leaks - It may be your problem?

Edited January 19, 2009 by Proper Job

[mykaskin]

I'm now racking my brain. Are you sure its a JP Lister? I've never come across one with a decompresser unless it is hand start only.

 

Hi Steve,

 

I didn't realise this, but there are hand start versions with valve lifters, and electric versions without. Is that right?

 

Obviously hand start versions can have an electric start retro fitted - sometimes sorely tempted (literally) to do that with mine!

 

Cheers,

 

Mike

[BuckbyLocks]

I'm now racking my brain. Are you sure its a JP Lister? I've never come across one with a decompresser unless it is hand start only.

 

I think all JPs, including the 4s and 6s have decompressors. The early ones have them in the Crankcase doors and the later ones on the Heads. The manual certainly shows them on all models.

 

You will really hammer the battery if you try to start from cold without using them. Unless there is a leak in the system you should not have a problem with the fuel after leaving the engine standing for a long time. You can always hear the injection of fuel into a JP anyway so you will know if the fuel is reaching the pot. Very satisfying squish if it is working properly.

 

The worst 'clunk' on JPs is the fuel pump coupling where if you have any wear at all in the tufnol spacer it knocks. As the timing is driven by this coupling always make sure everything is tight or it may slip and you will then find it very difficult to start the engine. Most afficianados can hear a JP at 4oo yards because of the fuel pump 'clack'.

 

Unless you are towing or loaded the high/lower compression screws are probably best left screwed in. You would be very lucky to get a JP to start with them screwed out. Even when hot we used to screw one back in before starting and recompress that one first.

[Proper Job]

Hi Steve,

 

I didn't realise this, but there are hand start versions with valve lifters, and electric versions without. Is that right?

 

Obviously hand start versions can have an electric start retro fitted - sometimes sorely tempted (literally) to do that with mine!

 

Cheers,

 

Mike

You jumped in while I was editing my post to add "unless it was hand start only".

 

You'd have to be a vertitable brick sh#t house to be able to hand start on high compression

[mykaskin]

You'd have to be a vertitable brick sh#t house to be able to hand start on high compression

 

I assume you mean "able to hand start without the valves lifted", as of course you can only start it on high compression mode.

 

I think the previous owners best attempts to get it going from warm was half a turn - which would mean you could leave the compression leavers down. :-)

[Proper Job]

The worst 'clunk' on JPs is the fuel pump coupling where if you have any wear at all in the tufnol spacer it knocks. As the timing is driven by this coupling always make sure everything is tight or it may slip and you will then find it very difficult to start the engine. Most afficianados can hear a JP at 4oo yards because of the fuel pump 'clack'.

It is probably the worst sound made by the engine. I know someone who spent ages trying to track down the noise, at its worst it sound like someone attacking it with a hammer

 

Second only to changing a K series Kelvin over from petrol to diesel

[Timleech]

You jumped in while I was editing my post to add "unless it was hand start only".

 

You'd have to be a vertitable brick sh#t house to be able to hand start on high compression

 

Surely you don't mean that?

 

I'm guessing you mean 'without decompressing', which is rather different. You'd struggle to start it at all, even with electric start, on low compression unless hot.

 

I used to drive a railway loco (standard gauge!) with a JP2, the starting handle passed through the buffer beam to the end of the crankshaft.

We found the easiest way to start it unless the weather was very cold was pulling it straight over compression with two of us on the handle. I could do it on my own if it was warm.

 

I've never come across a JP without decompressors.

 

Tim

[Proper Job]

Surely you don't mean that?

 

I'm guessing you mean 'without decompressing', which is rather different. You'd struggle to start it at all, even with electric start, on low compression unless hot.

 

I used to drive a railway loco (standard gauge!) with a JP2, the starting handle passed through the buffer beam to the end of the crankshaft.

We found the easiest way to start it unless the weather was very cold was pulling it straight over compression with two of us on the handle. I could do it on my own if it was warm.

 

I've never come across a JP without decompressors.

 

Tim

Tim

 

My JP3 does not have decompressors, but there is no facility to hand start it either. It is an ex Royal Navy JP3M.

 

In fairness, it's virtually a brand new engine. Having been fully rebuilt by the RN in 1953, it was put in a packing crate as a 'spare unit'. It was then put in the boat and has since only done around 400 hours. Even I have to admit it, its one of the sweetest running JP's I've come across (blood fuel pump coupling still knocks though!).

 

Mine starts quite happily after a couple of revolutions via the 12v starter.

 

I also know of another JP3 - ex standby generator - that does not have any decompressors. If it was auto start, there wouldn't have been anyone available to activate the decompressors anyway.

 

I think the bottom line is that there are many 'options' for starting. It just depends on the original spec for the engine and its subsequent history. It think air start was a potential option (although I may be thinking about later JS and JK models). I've never come across one though.

[Timleech]

Tim

 

My JP3 does not have decompressors, but there is no facility to hand start it either. It is an ex Royal Navy JP3M.

 

In fairness, it's virtually a brand new engine. Having been fully rebuilt by the RN in 1953, it was put in a packing crate as a 'spare unit'. It was then put in the boat and has since only done around 400 hours. Even I have to admit it, its one of the sweetest running JP's I've come across (blood fuel pump coupling still knocks though!).

 

Mine starts quite happily after a couple of revolutions via the 12v starter.

 

I also know of another JP3 - ex standby generator - that does not have any decompressors. If it was auto start, there wouldn't have been anyone available to activate the decompressors anyway.

 

I think the bottom line is that there are many 'options' for starting. It just depends on the original spec for the engine and its subsequent history. It think air start was a potential option (although I may be thinking about later JS and JK models). I've never come across one though.

 

Interesting.

The standard JPM book only shows rocker covers with decompressors, no alternative version.

Of course, because of the design change it would be easy to build one without if that was what was really wanted by selectively combining bits from older and newer engines, but a hand start option was pretty much de rigeur for small marine engines of the day. You wouldn't want to rely too much on this new fangled electricity stuff, with batteries which go flat, would you

 

Air start was certainly an option, but I've never seen it either.

 

Tim

[johnthebridge]

Many moons ago, Keith Christie showed me how to hand start a JP. I've tried it many times since and it's worked every time for me:-

Give it plenty of speed wheel. Turn it over 10/12 times without compression, set the extra fuel rod as Tim Leech has described, then lower the leading de-compressor. Turn it over gently until you come to compression. Stop winding. Take the lead decompressor off, and put the other one on. Grasp starting handle firmly with both hands, and wind. You have enough revolutions to get going before hitting compression, and it will fire whilst you're winding, without having to take one hand off to fumble for the other lever. Once it's going on one, drop the other lever.

Edited January 19, 2009 by johnthebridge

[Timleech]

Many moons ago, Keith Christie showed me how to hand start a JP. I've tried it many times since and it's worked every time for me:-

Give it plenty of speed wheel. Turn it over 10/12 times without compression, set the extra fuel rod as Tim Leech has described, then lower the leading de-compressor. Turn it over gently until you come to compression. Stop winding. Take the lead decompressor off, and put the other one on. Grasp starting handle firmly with both hands, and wind. You have enough revolutions to get going before hitting compression, and it will fire whilst you're winding, without having to take one hand off to fumble for the other lever. Once it's going on one, drop the other lever.

 

If your engine has the top style of decompressor, it's possible to arrange a length of cord tied around the raised hand start shaft with a loop which drops over one decompressor lever, if you have the right free length of cord it will give you the optimum number of turns of the handle to get up to speed before pulling the lever down, with both hands and no distraction of reaching out to knock the lever down as the cord will do it for you. Once that cylinder has fired, knock the other lever over by hand.

 

With the older crankcase door button decompressor, a cord looped around the button(s) and tied across to the side of the boat, stamp on the cord to pull the knobs out

 

Tim

Edited January 19, 2009 by Timleech