Low RPM when Fully Opening the Throttle

Hi all,
I have been trying to sort out this problem for a few days now. I have a PZ27 carb on a 150cc FT162FMJ engine.
When I open the throttle completely my engine revs upto around 8000 rpm, if I hold it open it slowly drops to 7000 rpm and starts to "hunt/miss".
While riding on occasion I get a small backfire and I get the hunting/missing.
I have opened the the carb and checked for any dirt and found nothing.
I have adjusted the main needle on the top of the carb up and down and tried to set the carb with the adjusting screw with each change in needle position.

I set the idle up to 3000 rpm and adjust the screw - what I have found is that I have to screw it all the way in before there is any change to the rpm and I have to unscrew it almost all the way out as well before there is any change to the rpm.... I am not getting any rpm change while slowly screwing it in or out.

I am going to check valve lash this evening.
Am I correct in thinking the engine should rev up to 10 000 plus...or do they only rev to 8000 rpm?

Any help or direction will be greatly appreciated.

Thank you all in advance

Why NOT ask the dealer? http://hondacg125.awardspace.com/bas...lt_finding.htm
Changed the stock spark plug? The stock one may f**ed : underpaid monkey NOT screw it to spec in bike factory / Shipping damage etc. NGK DPR8EA-9 is always a treat for these machine.
Exhaust leaks etc. Block the SAI is always a great prevention solution.

After stripping down the carb, cleaning the carb, setting the valves and going to a few local people for advise (who also didn't see the problem) I finaly got a solution.........:clap:

My PZ27 carb has 3 settings - I recieved the bike with the carb choke arm in the center position - which is the choke in the first position.

I thought that is where it should be but if I flick it down the bike revs all the way up to 10 000 rpm, pulls with plenty power and just responses to throttle changes like a dream....:taz:

I have been riding the bike for 3 months with the choke on, as well as trying to set the carb with the choke on...... Instead of looking for a big problem I should have looked at the simple things first....

Well I suppose thats how we learn - I just hope my stupidity helps someone one day lol :lol8:

At least I learnt a lot about the carb and learnt how to set valves on a bike - so no real time waisted lol