Lots of black smoke (hard to start)

[Nauty]

Hi. I've just rebuilt a Z482 to go in my boat (engine is a Beta 10)
Sorry for it not being an orange tractor although I do have a Kubota front cutting mower as well.
I got it in a sorry state although hardly used, 144hrs.
Bores were de-glazed , new rings and new gaskets all round. Put it all back together and set it up with water for cooling and the control panel supplied.
So it belches out black smoke and won't start unless I use lots of heat. When it runs it's fine, not much smoke, responds well to throttle and no issues at all.
Then if you turn it off and go to start it again immediately , it belches out black smoke and won't start unless you use lots of heat again. I'm thinking it's getting way too much fuel on start up.
I removed injectors, ultrasonically cleaned them although they were very clean and all seemed good with them.
Still exactly the same issues.
Any ideas anyone.
I didn't touch the injector pump , just put it straight back on with the same shims.
It's never been torn down before I did it.

 

[whitetiger]

A lot of black smoke can be too much load on the engine while starting, inadequate glow plugs, timing off, restricted air intake, injectors, injection pump, low compression, etc.
Cleaning the injectors in an ultrasonic cleaner is just a feel-good action. It is a waste of time, the injector must be popped off to check the pressure and spray pattern. They can shine like a diamond in a goat's butt and not function at all.
You should perform a compression test and have the injectors professionally tested and calibrated. It is very likely if you had the engine completely disassembled, the timing gears are timed incorrectly.

Check the air intake for obstruction.

 

[Nauty]

A lot of black smoke can be too much load on the engine while starting, inadequate glow plugs, timing off, restricted air intake, injectors, injection pump, low compression, etc.
Cleaning the injectors in an ultrasonic cleaner is just a feel-good action. It is a waste of time, the injector must be popped off to check the pressure and spray pattern. They can shine like a diamond in a goat's butt and not function at all.
You should perform a compression test and have the injectors professionally tested and calibrated. It is very likely if you had the engine completely disassembled, the timing gears are timed incorrectly.

Check the air intake for obstruction.

Thanks for the reply
No load on engine at all.
Timing was done correctly and once started runs perfect.
New air filter
I guess I could get the injectors tested , just no one within 80 miles of here that can do it , same for compression test.

 

[Nauty]

So I got the injectors tested and I was there when they tested them on an old Lucas machine, they were both toast so they supplied me with new ones. Fitted them but no different at all as afar as I can tell.

It's as though it's either getting too much fuel or not enough air. Intake is completely free and new air filter.
Timing is correct but wondering if I got valve clearances wrong and the intake isn't opening much , not likely.
Anyone have any ideas before I skip this engine.? I've spent about £2k reconditioning it and it looks like new or better but no use to me if it doesn't work.

 

[eserv]

So I got the injectors tested and I was there when they tested them on an old Lucas machine, they were both toast so they supplied me with new ones. Fitted them but no different at all as afar as I can tell.

It's as though it's either getting too much fuel or not enough air. Intake is completely free and new air filter.
Timing is correct but wondering if I got valve clearances wrong and the intake isn't opening much , not likely.
Anyone have any ideas before I skip this engine.? I've spent about £2k reconditioning it and it looks like new or better but no use to me if it doesn't work.

It doesn't have enough compression. you need to do a compression test. My guess is you have bent connecting rods.

 

[North Idaho Wolfman]

Yes do a compression test.
Valves should be .145-.185 mm or .008 in.

 

[Nauty]

I'd given up on this little engine but uncovered it last week for another go at it.

I got in touch with Beta and they said from the video I sent them it was low on compression and thought it must be a bent rod but both pistons are sitting 0.55mm above the block so that's in spec.

Did a compression test and both came out at 300psi so obviously that's the issue (thanks eserv)
So I took the head off and everything looks fine , turned the crank so both pistons were down from the top and poured a small amount of engine oil on top of them (about a 1/4" deep) . It's been there for 48hrs and not gone down at all so from that I think the rings are fine bearing in mind it has new rings on a deglazed 144hr engine.

So next I went to the head and the valves. I made a little levy/dam around them with BlueTac and filled it with water , again absolutely no seepage at all as I suspected. I never touched the valves on the rebuild apart from fitting new stem seals. This engine has done nothing.



The the only thing left is the head gasket which was a new but repro one from a very good supplier here in the UK (JEM Engines). They also have a full machine shop and deglazed my bores for me, they're a couple of hours away from me near Edinburgh but the gasket looks fine so I'm very puzzled.

Anyone any ideas?

 

[William1]

Glow plugs.

 

[thebicman]

The other big question is why was it taken apart at 144 hrs?

 

[Nauty]

It was partially submerged (gearbox and bell housing inc. starter)
The actual block was untouched.

 

[Nauty]

Once I'd removed the starter and all the corrosion at the rear it turned easily and no water at all in the engine.
You can see I'm not a fan of Beta red paint. Oil cap was the only survivor.

 

[North Idaho Wolfman]

Have you done a spill test on the injection pump?

 

[Nauty]

No I haven't , what is that?

 

[North Idaho Wolfman]

No I haven't , what is that?

That will tell you if the timing of the injection is right.
It could be that it's off and injecting to early or too late.
Can you see marks on the side of the flywheel?

Also did you measure the sqwash of the head gasket when you pulled the head the second time?

 

[Nauty]

I can't see the marks anymore but I could remove the gearbox and bell housing to see them.

What's the swash of the head gasket? I measured the thickness of it at 1.7mm , it's metal and 3 layers I think.

 

[Nauty]

Is this what I need to do?

Technical - Spill timing | Jem Engines UK

www.jemengines.co.uk

 

[North Idaho Wolfman]

I can't see the marks anymore but I could remove the gearbox and bell housing to see them.

What's the swash of the head gasket? I measured the thickness of it at 1.7mm , it's metal and 3 layers I think.

It would be how thick the head gasket becomes after you torque the head.
The final thickness is what's important.
Even .x mm will make a huge difference in compression.

Is this what I need to do?

Technical - Spill timing | Jem Engines UK

www.jemengines.co.uk

Don't do anything in the first part, Just remove the injector lines.
You can watch the level change via the delivery valve holder, it's not a good idea to open the injection pump up!
No need to cut an injection line or anything.
The second part for no timing marks might be beneficial, but you have to make 100% sure you get TDC right or everything will be off.
Look on the right side of the bell housing, there is normally a cover over a port (window) to see the timing marks.

 

[Nauty]

Well if I just leave the head off I can see the piston is at TDC ..correct?

 

[North Idaho Wolfman]

Well if I just leave the head off I can see the piston is at TDC ..correct?

Yes that will do it.
Then just follow the math on the link you gave me for the marking of the degree's that you need.

 

[Nauty]

New head gasket all back together and still have no start and black smoke

I should say if it's cool then it'll start pretty well with some heat from the plugs.

It's just when it's warmed up to operating temp , shut it off , it does this!!
Any ideas what that's pointing to ? Compression still?