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Lister SR3 smoky


John Lewis

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Hi guys, I've a Lister Sr3 which came with the boat I bought. It sat idle I believe for a long time, so I've inherited some issues..

 

She looks clean all over the engine and under rocker covers etc. All gaskets are good.

 

I have question marks over the first cylinder, I think she's firing in there but maybe not as much.

 

1. Anyway, the issue is she's still a bit smoky - white/blackish smoke when I hit throttle.

 

I've got the injectors re-conditioned - and it has helped a lot, but still I think she is quite smoky.

 

Is there further steps I can take? Do the pumps effect things...

 

 

2. Also she seems to be running into an air lock after sat for a few days.

The tank sits up on the side of the swim, and the fuel filter is mounted next to in, then Flexi to the pump.

The fuel filter is a fancy water separator unit - with 2 inputs and 2 outputs. So I am going to change that to the ordinary Lister one.

Can the height of the fuel coming in affect things?

 

Thanks a lot.

 

 

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It is not unusual for engines with heavy flywheels to smoke as you rev them, the faster you throttle up the more smoke they tend to produce. This is because the inertia in the flywheel causes them to overload for a while. If it only happens in gear I would suspect an overlarge prop.

 

I found it impossible to get our SL4s to produce an even exhaust stub temperature across all cylinders on idle so if that is how you are judging no. 1 cylinder then try again  when cruising with an infrared thermometer. I would also suggest that you check all the valve clearances but beware I think there are two different values depending upon push rod material. Hopefully someone who knows will either confirm or deny.

 

I think the Lister fuel filter is a tiny little thing that can be difficult to see fairly low down on the engine. Have  a good look round and follow the pipe from the lift pump.

 

Photo of the fuel filter because if it's a CAV agglomerator it will be fine. Two of the ports should be plugged. Where does the injector leak off pipe run to?

 

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Thanks Tony/Tracy 

32 minutes ago, Tracy D'arth said:

Its likely down on compression on one cylinder hence the unburnt fuel and white smoke.

First thing is to set the tappets.

Then get a compression test done.

 

Thanks Tracy, is there much involved in adjusting the tappets. Also how do they do compression tests on diesels. Ive only done a bit on petrol 2 strokes.

 

Tony - pic attached.

We disconnected from fuel filter for a while to diagnose problem.

She's just running temporarily off a separate tank.

The return pipe was just left open for the meantime.

 

Are you sure there'd by a separate fuel filter on these. I don't see one.

 

Would the height account for the engine being starved of fuel?

Also does the governor ever play a part in incorrect fuel delivery?

 

 

Ta

IMG_1147.JPG

The bucket does not play any part in the operations!

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1 hour ago, John Lewis said:

Thanks Tony/Tracy 

Thanks Tracy, is there much involved in adjusting the tappets. Also how do they do compression tests on diesels. Ive only done a bit on petrol 2 strokes.

 

Tony - pic attached.

We disconnected from fuel filter for a while to diagnose problem.

She's just running temporarily off a separate tank.

The return pipe was just left open for the meantime.

 

Are you sure there'd by a separate fuel filter on these. I don't see one.

 

Would the height account for the engine being starved of fuel?

Also does the governor ever play a part in incorrect fuel delivery?

 

 

Ta

 

The bucket does not play any part in the operations!

 

I can not see an engine mounted filter so I doubt there is one. The white filter may well have a water bowl on the bottom but that does not stop it being a filter. In fact all filters have a volume below the element to hold any agglomerated water. Its fine, you don't need a new one unless the head or bowl is cracked.

 

Lift pumps happily suck fuel from tanks on the bottom of the boat so I don't think tank height is a problem. In fact yours has a positive head so that makes it easier to get fuel to the pump.

 

While the governor adjust the fuel delivered to the engine it should not have any effect on fuel starvation unless the control rod/rack is jambing in the no fuel (stop) position. You can check this via the cover over the injector pumps. Are you aware of the cold start button and do you use it? If you push/pull it you might hear the rack jump forward.

 

Compression testing - you need a diesel compression tester that clamps in place of the injector. You can't hold one in against the press like a car/bike one. Probably get a professional to do it. Ideally get a wet and dry test, that is six readings.

 

Valve clearances. Get a piece of crayon or chalk and remove the rocker covers.

 

Turn the engine over until one valve is fully down and put a datum mark on the front pulley.

 

Turn the engine over half a turn (full turn on most engines, but your front pulley is driven off the camshaft so half a turn for you.

 

Adjust check the valve that was fully down and adjust the  clearance as required. NOTE what I said about the possibility of different clearances depending upon the push rods.

 

Move onto the next/another valve.

 

 

 

 

 

Edited by Tony Brooks
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9 minutes ago, John Lewis said:

Thanks Tony, I have feeler gauges alright, so should I check manual - and see all valves are same gap?

 

Also what do you think about the pump needing a service?

particularly the first one, as I suspected weak area here - due to the temperature on exhaust outlets,..

 

You should always check the manual. If I put this in (paging @RLWP) our Lister expert might pop up and give chapter and verse.

 

I don't thnk the gaps are the same but I am on about 2 different sets of gaps, not just a different one for inlet and exhaust.

 

 

The lift pump looks new to me. To test it put your thumb over the inlet and spin the engine a few revs. See how long the pump hold suction, expect at least 30 seconds. Same for the outlet but this time you are seeing how long it holds pressure. You could also check the delivery, expect about a small egg cup full per squirt.

 

 

 

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6 minutes ago, John Lewis said:

Yes I had to replace the lift pump, all working good now.

 

It was the high pressure pumps I was meaning..

 

So injector pumps. With a positive fuel head like you have any air leak should leak fuel out, not air in. Unless an injector pipe union is loose there are three places those pumps can leak from. The bleed screw on the front, the element securing screw on the back, or from a worn element from the bottom of the pump. All would cause the sump oil level to rise and the oil dilute. I think the injector pumps are unlikely to be at fault but when you stop the engine you physically more the rack to the no fuel position then if one is slightly twisted it could stop the rack jumping back to the run position. In that case some cranking might vibrate it into the run position. As I said check it through the injector pump cover. You must have been in there to bleed the pumps unless your engine hast he automatic bleed option. If it has the pump bleed screws will have thin pipe running upwards to the leak off rail in the rocker cover.

 

 

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Thanks Tony, I think with the help of my friend we\ll be able to trace the air leak etc.

 

It was the smoke issues I was trying to figure out.

Someone said if the injector pumps were acting up they could bee delivering too much fuel - or causing smoke issues?

 

Could that be right.

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SR3 tappet clearance. Both inlet and exhaust. Adjust cold. 0.014'' GO to 0.016'' NOT GO. Which means the 0.016 blade won't enter the 0.014'' gap.  0.015'' is nice. Don't adjust them too tight!!!! better a touch too slack than too tight

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10 minutes ago, John Lewis said:

And running here now for a few minutes, its hot from centre cylinder no 2.

The first is still cool, and the front cylinder no 3 is also fairly cool.

If I put my ear over the middle cylinder I can hear a knock coming through.

The others seem quite.

 

here's her running on tick over.

 

 

 

Normally the cylinder at the front of the engine (where the belt is) is considered No. 1.

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Certainly sounds as if no. 2 is doing more work but are the decompressors correctly adjusted (don't mess, you can wreck pistons if you get it wrong). But as I said I would not necessarily take a test at tickover as indicative of power balance when under load. Don't use the decompressor at much over idle in case a piston hits a valve.

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  • 2 weeks later...

I got a friend to do tappets, and with a new smaller filter, she seems happy.

 

I have the return line to plumb in.

 

As the tank sits higher than the engine return, will this fill up and make its way back up the pipe to the tank return?

 

Im trying to pick out a spot to mount it to...

 

thank you

IMG_1181.JPG

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34 minutes ago, John Lewis said:

I got a friend to do tappets, and with a new smaller filter, she seems happy.

 

I have the return line to plumb in.

 

As the tank sits higher than the engine return, will this fill up and make its way back up the pipe to the tank return?

 

Im trying to pick out a spot to mount it to...

 

thank you

 

 

Yes. The lift pump can produce around 6 psi so it can pump the return fuel up hill.

 

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2 hours ago, John Lewis said:

I got a friend to do tappets, and with a new smaller filter, she seems happy.

 

I have the return line to plumb in.

 

As the tank sits higher than the engine return, will this fill up and make its way back up the pipe to the tank return?

 

Im trying to pick out a spot to mount it to...

 

thank you

IMG_1181.JPG

The leak off rail is the pipework up against the rocker covers [Port side) your yellow fuel tubing can be connected to that and tother end connected to that disconected copper tube which goes to the top of the tank.

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22 minutes ago, John Lewis said:

Im not sure I follow you Tony.

 

The return is just drilling out a pipe at top of engine, just a drip now and again,

 

Does this not go back direct to tank?

 

On your engine that may be the case but on the self bleeding variant rather more would come out and that is at whatever pressure the lift pump can produce. In your case it must be just the leak by of the injector needle and the pressure behind that is in the order of 3000 psi so no problem blowing it uphill into the tank. As long as the end of the pipe is open the pressure will be just enough to get the fuel to the highest point so not much more than zero.

 

As  @bizzard says the pipe out of your engine should be connected to the top of the tank. If you look under the rocker covers you will see that pipe is connected to the small unions on the injectors.

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