Notallthere

Right sorted the two rings on the left are the directional bearing and when it rotates the lobe gets stopped at the top by that silly thin piece that goes between the two shafts. So the cam rotates and the decompressor stays put, so the side of rocker is lifted and released by the flat on the left. So now have to work out why it's missing the decompressor when the two rocker arms are the same apart from the rough casting on the one, but they do have the same casting number on them. Thank you all for your help and input. Cheers

Mech there isn't any problems with anything catching or interfering with each other.

That's a good eye. I will have a look in the morning cheers Mech.

Yep that's the same head spot on. I also see that there's a manual decompressor for it. I wonder if it could be fitted to mine. https://www.motorkit.com/en/spare-parts-skyteam-125cc-engine/23195-lifan-yx-125cc-engine-manual-decompressor.html

The ring with a notch has a one way bearing. Totally lost on this one.

Hope these help I just don't believe what a pain this is when I can sort out a V8 in minutes.

Hope the photo's help I really hope the photo's help and yes I have tried a spare battery with jumper cables and direct to the new starter motor.

Hi Mech First place I started with new starter and cables as the old cables had corrosion, I have tried the spare battery and jump leads and it's the same hard to turn over until you close off the intake. How do you test the auto decompression as not sure how it works.

Hi all the engine spins by hand with around 70psi compression, take the plug out then it will spins freely then once back it barely turns over, Adjusted valves so there all good . New battery New starter, it's like the start decompressor is not working. It's not very often I get stuck on a engine but.

Hi manual choke and still have the problem with the carb off. If I take the plug out it spins like a good one.

Hi yes fine if you put the hand over the intake it sucks you right in.

Manual choke and it's not on the engine and the mo, but still has the problem.

Hi yha new starter and battery and it's a Chinese 125cc so key start only. It is like it has to much compression ?

It is struggling to turn over with the air intake fully open. But if you cover the opening by 95 percent it then spins over freely

Feels as it should. All I do is a 95 percent close-our and away it goes.