Ah, I see, thank you for explaining it so clearly. I will next test to see if there is a spark at the spark plug, with a spark plug tester.

Forgot to say, welcome to TGMForum.

The flap you see is called the throttle butterfly, it controls the speed of the engine along with fuel and air mixture.  A choke would be a second butterfly at the other end of the carb which restricts the airflow thus making it suck more fuel for starting.

Hi Mick, thanks for your reply. I've attached three more photos I took, looking into the carburettor - isn't the flap thingy the choke? So when I put the lever on the tortoise setting, what does it do in the carburettor? (I sort of understand simple engines, but patently not very well!)

The engine tight spot is a bit difficult to diagnose without seeing it to be honest. 

The carburettor on your machine doesn't have a choke and uses a primer. So that shaft is referred to a Throttle shaft.  It's quite normal for it to float way from the idle speed screw when the engine is stopped. The governor will push it back when it's running.

Hello, I have an old Hayter Harrier 56 which stopped working a few days ago. I was mowing the lawn, and I think it ran out of petrol, as I couldn't see any in the tank. I filled it with petrol and then when I pulled the starter cord, the engine was very difficult to turn over. There was a very hard part every so many rotations (probably only one of the four strokes), and I couldn't get it to start. I drained out the oil and found that there was probably about 200ml in it, and I believe it needs 500ml. I refilled the oil with brand new Hayter engine oil, but the difficulty turning the engine over remained, and it won't start.

I started to take it apart, so I could see the carburretor, and I noticed that the choke doesn't close when the lever is set to the 'tortoise' position, for full choke. I can see that there is a rod that goes to the metal part on the top, which the choke is attached to, but the rod doesn't move back to close the choke (and I presume there is nothing else supposed to do this, unless there was a spring which has gone missing). I believe this rod is somehow connected to the governor on the engine. Should this rod be moving backwards (to the left on the photo) to pull the choke closed when the choke level is on the 'tortoise' setting? You can see that the cable is as tight as it can be, on the top right of the photo. I think in this photo I had manually adjusted the plate which is pointed at by the arrow in the centre of the photo, to close the choke, so it doesn't represent what actually happens when I try to turn the choke on with the handlebar lever.

Many thanks in advance to anybody who can help me, I appreciate you taking the time to answer all the queries on here.

Update:
The new motor arrived, it's too small. The measurements I read were wrong.
Looking for another option that's cheap, going to send this motor back.
Update2:
Seems to be a special motor.. Any ideas from anyone?

Hi Roo, and welcome to TGMForum.

I'm guessing as a lot of these machines come out of the same Chinese factory there would be using similar if not the same components.  I have no idea if they are exactly the same though.

Just curious as I've only done engine work of some of these HYUNDAI machines, what did they change between the 46 and 460 gearboxes?

Hi,
I have a Hyundai HYM46SPE that was given to me as a non runner. Cleaned the carb and got it working but then discovered that the drive gearbox is broken. They updated that model to the 460 and I cannot find a replacement for the older 46 model. However the Cobra M46SPB transmission 23050200201 seems almost identical. Has anyone had experience in this?

Update:
Was able to smash the starter open (it was locked up beforehand, the top 'carbon' was cracked), I got the plastic bit with the wires out, going to work on desoldering the cables to mount them on the new starter.
 

Yeah, was going to buy that but can't afford 100 pounds.
I think i'll just have to snip and strip the wires off then.