Honda CG 125 valve clearence

[Flixi]

Hi, little while back I have posted a thread asking for help with my Honda CG project... Thank you very much for helping me, I have done fair bit of work since then, the engine runs nicely now and I have adjusted the carburettor.

But (unfortunatelly ) I have got a new question:
When I turn on the engine I have noticed (I think quite loud) tapping noise coming out of the top of the cylinder, I have read is perfectly normal for a tapping noise to be present as long as it's not extremely loud, but I thought it would be worth checking the valve clearance, just in case.
So I have followed the guide from https://hondacg125.awardspace.com/valve_clearance.htm and this video https://www.youtube.com/watch?v=-4CrFwli-v0 and I have also read a threat previously posted on here, where a guy was asking about the same thing. Like him I got stuck on the part where the rocker arms are supposed to be 'rocking' when aligned in the correct position - they don't, they are rock solid.

I have tried turning the engine over and over, always aligning the T symbol and eventually I have found a position where the RIGHT rocker arm moves ( only by about 5mm up and down) but the LEFT arm is still unmovable, stuck to the valve and I definitely can't fit my gauge in the (atm nonexistent) gap. Does this mean that the left arm is tightened too much and I need to give it more clearance?

Or am I still in the wrong position? Although there just doesn't seem to be a position where both arms are rocking...
how much of a movement should I expect in the arms anyway?

I would be really thankful for any advice about it, because I don't want to mess it up by adjusting it in the wrong position or something....

The bike is a 2001 W front drum break model

[Nobby the Bastard]

On TDC (the T mark on your flywheel) both valves should be shut and you should be able to measure the clearance between the valve and the rocker,

If there was any clearence, if you were bonk the rocker above the valve with your finger you should hear an audible knocking sound.

CG valves have old-style nut-and-screw tappet. I'm not going to waste my time explaining how this works to you when there's a whole fucking internet out there.
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Nobby the Bastard]

Right, here's a simplified picture of your head.

The black bit is the rocker, the blue bit is the valve.

The red bit is the locking nut. This needs to be released before you start to adjust the valve. The green bit is the threaded bit that you use to adjust the clearance. THere should be a slot at the top of it for a screwdriver.

You need to release this, then reset the clearence (don't put a feeler guage in and then just tighten up the screw, you need to adjust the screw and then see if the guage will go in, repeat until you are happy....) and then, when you are content that the clearance is correct, then tighten the nut (red) whilst holding the adjuster(green) still with a screwdriver

https://i428.photobucket.com/albums/qq9/Nobbythechihuahua/Valve_zps6523479f.jpg
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[tomh]

If the valve clearance has never been checked then the valve will wear into the cylinder head, causing the valve clearance to reduce. Eventually there will be no valve clearance at all and this is what is most likely your problem. Make sure your on the right stroke at TDC and loosen off the locknut and adjust until it is to spec using the above information.

It is important that this is sorted as the valve is now always being slightly pushed open. The valves cools themselves by touching the seat in the cyclinder head. This will no longer happen and can cause the valve to burn out.

You should also notice that cold starting will be massively easier when the valve clearance is right.

[Flixi]

Ok, Thank you, I will do the addjustment, see what it'll look like then..

It's my fisrt bike so I'm kind of learning everything on it, sorry for the novice questions, the help is much appriciated though

[Robby]

5mm of play in a rocker arm is too much, and will be noisy. You should have about 0.1-0.2mm of play at the slackest point.

The rocker arm transfers the movement of the cam lobe to the valve, pushing the valve open. The clearance is there to allow for the expansion of metals as they heat. When the valve is open, the rocker arm is pushing it open, so there is no clearance. When the valve is closed and the rocker arm is against the smallest part of the cam, there is a tiny clearance to ensure that the valve is not being held open.

If the clearance is way out (like 5mm out) it suggests that someone has tried to set the valve clearances with the cam in the wrong position. It shouldn't run at all in this case.

[Flixi]

Oh sorry, that was a very bad estimate on my side my boyfriend had a look at it and assured me there isn't more then 1mm play in it... Anyway, we have also repositioned the whole rocker assembly a little as it seemed it was not sitting on quite properly and Tada! the left arm started to rock a little as well, when we aligned the T mark... so we adjusted the valves, following the instructions I have read here/the manual, and it should now be correct...

However there is still a rattling/fast ticking noise in the engine, I think I can now only hear it when the throttle is disengaged and the engine is returning from high revs to idle.. here https://youtu.be/xWphcngUt6M is a video I made of it, it is defifnitely coming out of the top of the cylinder.... is this normal noise, or is something still wrong? What, beside the valve clearance could it be?

Oh and this has been shot when the engine is pretty cold, running for few minutes in the shed (where it has been for the past few weeks since I bought it ) we didn't have chance to test it on a hot engine...