TOPIC:

I'm having trouble with my 82 440 running. I rebuilt the carbs in March. I've installed a modified air box (don't have enough room since lowering the suspension) and a Mac 2 into 1. The Mac didn't have any baffles so I found some universal ones and installed them.

I've got the 440 to idle very nicely but in neutral she won't rev past 5k and backfires on deceleration. When I've taken her out to ride, she stumbles. I have to very lightly twist the throttle to get her moving but eventually she'll get up to 30mph.

So, am I correct thinking im running too rich and need to either jet the carbs or adjust the pilot screws. Thanks in advance y'all.

Here's a shot of the modified air box and a stock one.

If the carbs have stock jetting, the mixture is likely too lean, which means too much air relative to the amount of fuel. If the bike barely runs and will not exceed 30 mph, I say there is something besides a jetting problem.
Are the carburetor holders and the carb to air box tubes soft and relatively new?
Has the fuel level in each carb been checked to be in the specified range?
Are the carbs spotlessly clean inside, especially the tiny low speed passages?
Is the ignition system up to snuff? Is the mechanical advancer working smoothly?
What was changed on the air box? I am not familiar enough with that model to tell from the pictures.

Are the carburetor holders and the carb to air box tubes soft and relatively new?
Both intake and exhaust boots are brand new.
Has the fuel level in each carb been checked to be in the specified range?
I'm gonna say yes since they both "leak"from the overflow nipples at the same time when primed.
Are the carbs spotlessly clean inside, especially the tiny low speed passages?
From what I remember yes. I might clean them again.
Is the ignition system up to snuff? Is the mechanical advancer working smoothly?
As far as i know. Have not troubleshot this yet. Any tips?
What was changed on the air box? I am not familiar enough with that model to tell from the pictures.
Basically I cut the lower section off the air box and sealed it with a flat piece of aluminum and RTV.

If the carbs are overflowing, then the fuel level is not correct, or the overflow tubes are cracked ( if that model has them), or both.
The floats and float valves control the flow of fuel into the carbs as well as the fuel level. The floats care not what position the petcock is on, or if there even is a petcock at all. When properly set, the floats will stop the flow of fuel into the carb, unless the float valve is not sealing.
Flooding carbs will contribute to poor running and make it impossible to properly tune them.

If there is a mechanical advance left from the points ignition, you can easily test it by trying to turn it fron its default position to fully advanced. If it moves freely and snaps back quickly, and the weights move freely on their pivots, it is probably fine.
If your new ignition has the advance curve programmed into the igniter, then there should be no mechanical advancer to test.

Ok, I believe I misspoke. Im guessing that the float level is good but I will double check when I pull the carbs. I saw somewhere a guy made a gauge out of a baby medicine syringe and hose I think I'm gonna try and make.