Diesel generator question

My son has just bought an ex MOD diesel generator with a
Lister-Petter single cylinder electric start engine. When we
unloaded it last night I gave the hand crank a couple of turns
and it rotated freely with the decompressor engaged, and seemed
to hit compression when I disengaged it.
Just tried it again and it is solid whichever position the
decompressor is in, can't even rotate it backwards with a
screwdriver in the fan.
Pictures can be seen here
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Any ideas appreciated.
Mike
I am away from home from early tomorrow morning so will be unable
to reply to answers/questions until Friday.
Reply to
Muddymike
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Petter AA1. Sounds like you've got a Diesel lock to me, but why it doesn't squidge out of the decompress or when its open I don't know ......
Reply to
kimsiddorn
More likely that the electric starter motor has jammed in mesh. Removing the starter should free it up. This happened to me when I had an AA1 generator.
Reply to
crn
Thanks guys I will check both points over the weekend. I assume that removing the rocker cover and depressing a valve should clear a diesel lock or am I on the wrong track there? The starter does spin if power is applied, but will remove it and take a look. At least that will give me access to the starter ring to attempt turning it backwards. I have little experience with small diesel engines so any more advice greatly appreciated.
Mike
Reply to
Muddymike
I'm baffled here. You claim that the starter spins but that the engine is locked solid, you can't have it both ways!
Julian.
Reply to
Julian
By feeding power directly to the starter motor, the starter motor spins without engaging to the engine. I did this to test if the starter motor was jammed in mesh. If I try powering it normally then use the starter switch on the controll panel the pre engage solenoid throws but the engine does not turn.
Mike
Reply to
Muddymike
Ok so I have it turning.
Starter off and could not turn it by prying the ring gear either way. Rocker cover off and depress a valve, still wont turn. Head off and it turned straight away. Very little carbon in there but one bit was loose. Cleaned it all up, re-assembled and it turns a treat.
One more question. Can anyone tell me which way the engine stop lever should be to start the engine? It can be clearly seen in this picture at the point of the red arrow.
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this position it is up against an adjustable stop, rotated to the right it just sit against the housing. Sadly it has no markings so I don't know which way is on or off.
I have tried crank starting it but with the starting handle so close to the floor and without knowing the start position of that lever I had no joy. I have a couple of 12 volt batteries on charge so hope to try it on the electric starter tomorrow.
Mike
Reply to
Muddymike
Ah, This one goes back towards the genny or forward towards the exhaust.
Something I forgot to ask. What fluid goes into the "Start Pilot" show in this picture?
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injects something straight into the inlet manifold.
Mike
Reply to
Muddymike
Slacken off the pipe union on the injector and crank the engine. When it leaks diesel you have found the "on" position.
Reply to
crn
You don't need to go that far, you'll hear the injector ''creak'' when you crank it over.
Julian.
Reply to
Julian
No Joy, no fuel at the injector. Are there any particular tricks to priming this system? I have cracked the outlet union from the filter and pumped the primer until fuel leaks. I have then disconnected the injector pipe union and cranked the engine over with the "on/off" control in both positions but still no diesel at the injector pipe. Remember this engine has been cranked quite a lot without a fuel tank.
Mike
Reply to
Muddymike
I've taken a look at those pictures and I can't see the injector pump - I wonder if it's similar to the likes of the Lister LD and is hidden behind a crankcase door?
It's obviously at the other end of the pipe from the injector :-)
Anyhow, find it. Sometimes there's a screw near the top of the thing, you loosen it and pump fuel to bleed the pump, If there's no obvious bleed screw then bleed at the fuel inlet pipe to the pump. After that bleed at the pump outlet by slackening the injector pipe - you'll need to crank it a fair bit with the decompressor engaged, next work along and bleed again at the pipe to injector union.
If you think about the above you'll see that the course of action is to bleed the entire system working along in stages from the tank - that's basically the same for any Diesel engine.
Julian.
Reply to
Julian
Thanks for the words of wisdom Julian.
The injector pump seems to be buried inside the end of the crankcase. I will take a good look to see if there is any kind of bleed screw. The fuel inlet and outlet unions are a sod to get to with a spanner but I will have another go. I have not had any dealings with small diesel engines before so this is a learning curve for me. I assume that once air gets into the injector pump it does not easily pump it out.
All help and advise greatly appreciated.
Mike
Reply to
Muddymike
When you're there you'll see for yourself which way the stop start lever works, normally the fuel rack is opened via a spring, counterbalanced by a centrifugal governor.
The fuel inlet and outlet unions are a sod to get to
Just the same as any other Diesel, this one is very very simple with no added bells and whistles like you find under the bonnet of a Diesel car.
I assume that once air gets into the injector pump
It always ''easily'' pumps out - the trick is getting to the best bit to pump it out from :-)
If I run a Diesel tractor out of fuel, often as not I'll maybe just try slackening one injector pipe at the pump and see if it'll prime itself and start pumping - after some cranking with one cylinder firing the others will join in and Bob's your uncle. Following some sort of strip and re-assembly or other works, I'd not be expecting to get away with that and have to start from first principles.
Julian.

Reply to
Julian
I have just spent an hour on it and still no joy. By removing the fuel filter, but leaving it hanging on the flexible feed and supply pipes I was able to get a spanner in to slacken the inlet union to the injector pump and diesel appeared straight away. I then removed the injector pipe completely, lots of cranking with the start stop control in both positions and still no joy. I then slackened a bigger union on the pump that the injector pipe connects through, lots of diesel shot out both when cranking and priming. Nothing with it tightened back. I then removed it completely and found a plunger on a spring inside, a none return valve perhaps? Lots more cranking and still nothing. I even tried a vacuum pump on the injector pipe whilst cranking and still nothing. I am beginning to think the injector pump is knackered.
There are three studs holding the housing that the injector and supply pipe attach to which may be the injector pump itself. Am I likely to upset the timing by removing it for inspection?
Mike
Reply to
Muddymike
Yes, that's right, it's a NRV. I have found these stuck on engines that have stood for a..g...e....s.... in the past, I didn't mention it before because it sounded like we were getting in too deep. Anyway, you've found it, check it's free and clean, I'd be very surprised if you fail to get it to pump fuel, given that you've got fuel to the underside of it.
Lots more cranking and still nothing.
I should be very surprised. Pump don't normally knacker. Obviously they wear over time, but on an engine like yours it'll probably outlast you!
I wouldn't think so. I'm not familiar with this engine, but the obvious is to check for the position of any shims you may come across.
Julian.
Reply to
Julian

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