50cc slowly dies when full throttle, HELP!

[islandRider]

[FIXED] - I had to buy a feeler gauge and adjust the valves

hi everyone!

I have a Wangye 49cc 193qmb 4-stroke scooter.
It has 8000+ km, but has given me almost no problems (besides a broken driving belt once ). That is until now...

Since 2 weeks ago or so it has not been able to reach its top speed (now 45-50, used to be 60km/h on flat road) and goes uphill very slow (35-40km/h, instead of 50 normal).

Then 1 week ago it started to act even more weird. Every time I start it up and drive away it will slowly lose power after 1 minute or so.
Even when I give full power it keeps going slower until I stand still and it dies on its own (Heres a video of it:
)
Then when I start it up again it takes a while. even when I give it some extra gas. So that makes me think it does not get enough fuel OR too much air, right?

Or could this be the carb? I could get a new one. But since I live in the Caribbean it will take some time and extra money to get it here.
I cleaned it with carb spray and cleaned the nozzles with pressurized air. But that did not fix it.
I checked for leaks in fuel and air lines and cleaned the fuel filter. Again, with no luck.
I adjusted the A/F screw and the idle. No luck either.
The only thing I could see what would be wrong is the spark plug OR the valves.

Oh and also, when i disconnect the fuel line the fuel flows out. So that's not the problem either :/

I hope I have given you enough information with this and the video. If not let me know and I will reply asap!

[scooterduder]

Do you have oil in it?it sounded like it was knocking a bit before you gave it gas. make sure your getting oil to it.

[Firehawk989]

Get a feeler gauge and adjust your valves. It's easy to do and is something you need to adjust every few thousand km on these scoots.

[islandRider]

You are right firehawk. I did buy the feeler gauge and found out the valves were way too tight.

I forgot to change this forum name to fixed, my bad.
Thanks anyways, you are the only one on all the forums that actually got it right

[Firehawk989]

No prob! Glad you got it sorted. When people start having trouble with poorly running Chinese scoots, this is one of the most common solutions.

[mmsscooters]

Make sure you adjust the valves at the right top dead center,there are 2 top dead centers, you need the magneto to be on the T line, and the cam needs to be positioned so that the large hole is on top at TDC, if the big hole is on bottom your valve adjustment will be wrong. make sure the 2 small holes are lined up with the top of the head too

[rv1160]

Hey guys - same problem Tao Tao 50 - adjusted valves and runs now but bogs at full throttle - figure it might be a fuel carb adjustment but after removing the tamper proof plug - I see a square (male) not a flat slotted screw - how the heck do I adjust that - think I'll just buy a new carb - never seen such a thing

[islandRider]

Well I'm not a scooter expert at all. but did its start bogging only after you adjusted the valves? Mine did that as well. For me it was a bad spark plug. It would not produce a spark every time, so some stuff entered the exhaust. only to be egnited when the spark plug did work.

So try changing the spark plug. otherwise it could be that you did not adjust the valves in dead center (read mmsscooters comment) or that your air fuel mix is too rich (i think?).

Would be good if someone with more skill could approve what i just wrote here. Or just make your own post I guess.