Lister SR3 not turning over

[TragicSlip]

Hi all,

 

Complete amateur (just got my first boat), so go easy on me.

 

I’ve done a few journeys on the boat now, and it has been absolutely fine. Went to go and start it up today and it’s not turning over. Sounds like it’s struggling. I don’t want to keep trying as I am aware this can damage the engine further.

 

The only things I have done that may have any effect on the engine in any way, are putting a bit of oil in and tightening the stern gland a little.

 

If anybody has any idea what may be going on and how to solve it, I would really appreciate the help.

 

Cheers in advance,

Ethan

[Jen-in-Wellies]

Welcome to the forum Ethan.

What you describe sounds more electrical than mechanical. Most likely a flat starter battery, or a dead starter battery.

Do you have, or can you beg, borrow, or buy an elecrrical multimeter? This will help hugely in finding where the problem is. 

First question. Is there a warning lamp in the cobtrol panel for the battery/charging circuit? This should be lit before starting the engine, with the key on, then go out as the engine fires up. If you have one, what does it do?

[Tony Brooks]

Probably flat or knackered batteries. Batteries work far less well in the cold.

How are you charging them? How long do you run and at whet engine speed each day.

Post a photo of the belt area at the front of your engine so we can see if it has been modified to give half decent charging al low speeds.

3 minutes ago, Jen-in-Wellies said:

This should be lit before starting the engine, with the key on, then go out as the engine fires up

 

True, but on an SL it may not if he does not rev the engine a bit.

[bizzard]

It would probably start on a low battery if you use the de-compressors, best if the three levers are linked together.

[David Mack]

Does this engine have a Lister LH150 gearbox (many do)? These are in forward gear when the engine is not running, and once the engine turns over the gearbox hydraulics put the gearbox into neutral. So if you have overtightened the stern gland the engine may not be able to turn over, especially if the batteries are a bit down.

[TragicSlip]

Cheers to the lot of you! It was of course the battery!

 

I can’t promise that I won’t be back with more questions requiring painfully simple answers. I will try to make my mistakes slowly and more importantly never the same one twice. 
 

Cheers again,

Ethan

[Jen-in-Wellies]

14 minutes ago, TragicSlip said:

Cheers to the lot of you! It was of course the battery!

 

I can’t promise that I won’t be back with more questions requiring painfully simple answers. I will try to make my mistakes slowly and more importantly never the same one twice. 
 

Cheers again,

Ethan

Glad you got it sorted. Don't worry, we (nearly) all started like this. 

[Tony Brooks]

16 minutes ago, TragicSlip said:

Cheers to the lot of you! It was of course the battery!

 

I can’t promise that I won’t be back with more questions requiring painfully simple answers. I will try to make my mistakes slowly and more importantly never the same one twice. 
 

Cheers again,

Ethan

 

Many thanks for coming back and telling us what the problem was, many don't bother. When they do come back, like you, we can all learn from it.

[Roxylass]

Bizzard you mention compression lever linkage

I was under the impression that you put compression 

levers over one at a time starting with No1 cylinder 

If not I will inquire if primrose eng has linkage

[bizzard]

17 minutes ago, Roxylass said:

Bizzard you mention compression lever linkage

I was under the impression that you put compression 

levers over one at a time starting with No1 cylinder 

If not I will inquire if primrose eng has linkage

If you have help then with someone on the levers with someone on the starter button. You could easily make your own linkage with strips of Meccano and small nuts and bolts. Loads of cheap s/h Meccano on ebay.

[Steve56]

On 06/01/2026 at 07:51, Roxylass said:

Bizzard you mention compression lever linkage

I was under the impression that you put compression 

levers over one at a time starting with No1 cylinder 

If not I will inquire if primrose eng has linkage

Normally on a Lister engine the decompressor levers were all individual and not linked. For hand starting you would operate one at a time. Lister did offer coupled decompressors as an optional extra. These were more for generators and suchlike where the decompressors were operated mechanically.

[zenataomm]

What do you actually mean by not turning over?
Does it move at all but just not over compression?
If it doesn't move it all then it could be either seized or there is water in the cylinders.
Lift the dipstick, what colour is the oil, does it look like chocolate milk?

Turn on all your lights and press the starter. The lights should dim but if they really disappear then I guess your battery(ies) are flat.

[bizzard]

2 hours ago, zenataomm said:

What do you actually mean by not turning over?
Does it move at all but just not over compression?
If it doesn't move it all then it could be either seized or there is water in the cylinders.
Lift the dipstick, what colour is the oil, does it look like chocolate milk?

Turn on all your lights and press the starter. The lights should dim but if they really disappear then I guess your battery(ies) are flat.

I doubt theres water in the cylinders as an SR3 is air cooled, unless he left off the W from SR3. Although if he has a vertical exhaust pipe I suppose rain water may have entered the cylinders.

[zenataomm]

12 hours ago, bizzard said:

I doubt theres water in the cylinders as an SR3 is air cooled, unless he left off the W from SR3. Although if he has a vertical exhaust pipe I suppose rain water may have entered the cylinders.

I was trying to cover every single common possibility as OP started with "Complete amateur (just got my first boat), so go easy on me."  He then explained things which could easily be misunderstood, yet might be essential clues.
The bloke next to me on the moorings let his exhaust line up with a pipe outlet exiting from the bank.  It only took a gentle but regular dribble to find the one cylinder on his SR2 that had rested on its exhaust stroke.

I reckon it's his battery(ies)

[jonathanA]

On 09/01/2026 at 14:10, zenataomm said:

I was trying to cover every single common possibility as OP started with "Complete amateur (just got my first boat), so go easy on me."  He then explained things which could easily be misunderstood, yet might be essential clues.
The bloke next to me on the moorings let his exhaust line up with a pipe outlet exiting from the bank.  It only took a gentle but regular dribble to find the one cylinder on his SR2 that had rested on its exhaust stroke.

I reckon it's his battery(ies)

Funnily enough about 6 posts earlier the op came back and told us that it was his batteries...

 

So maybe add reading the whole thread to "covering all the possibilities..." 😅😝🤣