1/2 - WOT cough/bog (i cant figure this out)

[oldskool83]

i have been dealing with a problem for the last 2 months. its been to a dealer also.

1st i had the reed replaced with new boyeson ones
2nd i thought my coil was bad since it was spliced and put back together, so i replaced with new OEM and it did nothing. it had good metal on metal contact with the frame also.
3rd i swaped out a CDI for another one i had, this only helped when i wanted to let the clutch out and ride it.
4th i played with the jetting for 4 hours and still get the 1/2 throttle bog.

everything is at stock settings on this bike. if i ride the bike and get to 1/2 throttle it will kind of sputter and some times catch its self only yo bog again.

i have not lost any radiator fuilt either, its at the same level it was 2 months ago. my plugs are turning out a color between milk chocolate and dark chocolate, kinda a darck brown so i konw jetting cant be that far off.

what the heck causes a cough/bog that goes into full shut down if i dont let off the gas?

it fires up 1st kick every time so i have compression since its fully rebuilt, and new gaskets/all seals too. carb is rebuild with 70% of it having new parts, its clean also.

will a fried CDI only work untli certail rpms?
stock jetting is:
125 main
52 pilot
needle at 3rd clip (seemed to run better at 4th for me)
air screw 2 turns out

now WTF am i missing here, some please help, nothings working!:confused: :wondering

ps its a 1989 cr80

[jason 32]

it sounds like a passage in the carb might be clogged up - try soaking it and blow ing it out with a air compresser,
also -sounds like its starving -in the mid --
if not clogged up- mabe a bigger pilot jet -
remember those jets are verry small-
so are the air passages in the carb
whats the plug look like?

[oldskool83]

plug looks like a color a little lighter then dark chocolate. i thought the main jet controlled anything over 1/2 throttle

[jason 32]

the fuel still flows through the pilot -
it doesnt just close off-

[oldskool83]

well i work on the bike for 2 hours tonight.

1st i cleaned the carb out again with really strong spray cleaner and then used compressed air to get all the stuff out, then i set the float to 19mm, it was off by 3mm at 21mm. next i took out the pre-oiled air filter i had in and then fired up the bike.

i was able to snap it to WTO and then snap it back with no bog, if i tried to ride it then it still bogged and sputtered over 1/2 throttle but it tried to find its self but would just bog and die.

after my ride i noticed it just wanted to die in neutral. i found out then the carb is missing the air screw spring, i had it set and this is why it died then, it just vibrated to the closed position....my plug was very lean then so i will not do anything else to it until i get new parts around thanksgiving next week.

i also ordered a factory air filter because i feel the oiled one is restricking flow. i think i am getting there i think:confused: