Looking for a bit of advice guys.
My 125 started acting funny this morning. Revving up very slowly and not accelerating and maxing out at 10mph.
It would take a bit of starting and would die completely when I opened up the choke.
Was thinking either water in the air filter (washed it yesterday) or dirty carb (had to go to reserve earlier this week).
Does that sound about right? (Beginner). If it's the carb. Is it a tricky job to do or is it worth paying to get it done?
Was ok up until this all started.

Did you dry the filter properly?

Carb is easy enough, but can be fiddly, especially refitting. Make sure you are meticulous about the cleaning, do it in a dust-less environment, etc etc.

Otherwise, I'd check all the usual bits first - Oil, plugs, leads, etc.

I hope you didn't jet wash it! If the air filter is wet then the air won't get through and it will hold back a lot. Not sure why you would want to wash one with water though. Also there could be water in or around the coil and plug cap which may be earthing out the spark. That's why I don't wash my bikes from one year to the next.

Sorry guys. Meant washed the bike! Had the bike 3 weeks so not up there with it yet.
Had a look at the air filter (a slight bit of rust noticed - replacement ordered).
Checked the fuel tank breather tube (ok)

Have now noticed a slight squeeling noze from the clutch area before the engine dies. New plates?

Is it running OK now apart from the squeal?

I would look at each problem separately.