ATC200 Bog Blues - any ideas?

[CaptainRon]

'82 ATC200 - anything over 1/4 throttle starts a "bog" in the engine.
Tried:
1. Cleaned carb out no less than 25 times (blown air through all passages after removing all jets and screws)
2. Set float at different heights
3. Tried all needle clip positions
4. Tried with and without air filter and airbox
5. Changed fuel tanks and fuel filters, checked fuel flow
6. Checked spark plug (it's new and has light brown color to electrode)
7. Adjusted idle mixture screw
8. Checked choke position - putting choke on while bog present kills engine
9. Checked to see if all jets stock size - they are (38 pilot, 105 main)

Any more ideas on where to look for problem?
Could a weak stator cause this?
Engine starts and idles and runs perfectly until bog kicks in at above 1/4 thottle.

[longbedGTs]

Any exhaust restrictions? Have you checked the timing? FWIW, I had an 82 200 and it had the same symptoms yours has. The timing had to be off as teh exhaust would glow red after running a while. I sold it before I correct the problem. Good luck!

[CaptainRon]

I have not checked the timing, but it seems easy to do so will try that also - thanks for the suggestion.
Ron

[CaptainRon]

Found out, by switching to another carb, that the needle used was a big fat one.
The needle in the spare carb was a thin one, like all my other needles.
Put just the thin needle in, and it worked fine.
Hope this helps someone......