Ts50 Bogging issues

[skyliner22]

Hi guys sorry to be a bother but i need to be pointed in the right direction.

I took in a Ts50 from gumtree for silly cheap, literally silly cheap, After fixing all the issues to get it ready for an mot its started to behave a bit weirdly.

When in Neutral i can freely rev all of the band easily without bogging and it does idle for a short while i can blip the throttle and it will stay on.

When knocked in to gear i accelerate to about 5000 revs in second gear and it just bogs down and starts juddering and starts to slowdown i have to knock it down to first gear.
Im unsure of where to go next as the carb has been off and ive given it a new set of seals set the float height made sure the jets are clean. Removed all old petrol from the tank and flushed it out

Does anyone know what else i could try?
I thought it would of been fuel starvation but really not sure on this one

Thank you
____________________
Singe Cylinder fan club: CG x 2 , NC50 x 1, Kawasaki Kx250

[Sir Clip]

Had a mate who ran a couple of TS's at various events years ago, including newly-bought (secondhand) one with a cone filter of unknown/questionable performance, similar symptoms as you describe. We enclosed the filter in a sandwich box, and tweaked the holes we had made in it to get it running nicely.

Turns out the holes we made in said sandwich box wern't optimaly tuned for the mud and rain on an enduro couse, but it gave us a clue!

[jaffa90]

The engine uses more fuel under load and needs an exhaust to get shut of the gases.