so my bike was running all that well and I cleaned the carburetors..now it still runs about the same it bogges down and shuts off if you open up the throttle at all, unless u go really slow..... Periodically it kinda backfires just a little, and a heavy blue flame shoots out...? Any ideas? Spark plugs are good....
There are a few things that may be possibly going on.
When you cleaned the carbs, did you also adjust them? It sounds like you need the carbs properly adjusted and synced. With the free flowing full muzzy exhaust you have, it is common to see a blue flame if the engine is running too rich. With no cats in the exhaust system, occasional flames are not suppressed.
What you describe is rich bogging. Check to make sure you have good airflow (from airbox to carbs), properly connected carb boots and properly installed and tightened exhaust.
Do you know of any mods that may have been done to the carbs? That is where you may want to start your diagnosis. Chances are with the full Muzzy the carbs may have already been rejetted, which may be the cause of your problem. If the main jets are too large, they can also cause the problem you are having.
Also something else to consider as far as power loss/bogging goes...
Have you done a compression test to see if your rings are OK ? One way to check it is too smell your oil. If it smells real heavily of gas, then it is possible that extra fuel is not being burned and leaking past your rings. On a 1992 Ninja 250, it may be time to look at rebuild. A compression test will let you know whether or not your cylinders are good or not.