and here we are with nomenclature difficulties... "bogging out"
some seem to think its when its too lean.
some seem to think the term applies better when its too rich.
i prefer
"it dies when given full throttle" for too lean.
" it runs but doesnt really rev" for too rich
if you need to tweak the choke whilst riding...it is lean. very lean.
what causes this? forget airleaks, they are only a concern at idle.
a blocked jet is likely.
a blocked fuel line/filter calls second place.
a blocked vent on the petrol tank takes third place.
you can eliminate the last two issues by seeing how fast/consistently it will flow from the (disconnected from carb) fuel line into a handy glass or similar vessel.
and lastly, very rarely...the clip comes of the needle and its no longer being lifted by the slide. idle is fine but it stalls as soon as the throttles opened.