I've got a 2000 Honda shadow ace vt750cd2. Back cylinder is running too rich blowing liquid gas out the baffle of the back cylinder, making the spark plugs black and wet with gas.

problem in the low cylinder
could be a leaking valve ( valve clearance ) or problem rings
both pistons have to be the same

Yes, once you remove the baffles this reduces the back pressure hence clearing the engine cylinders more quickly, this means a leaner fuel mixture, go up maybe 2 sizes, run the bike and just check the performance or even easier maybe dyno tune.

Bummer, you're probably correct on the not firing cylinder.
Narrow down which one by idling the machine for as long as it takes to feel warmth at an exhaust port..
So, you need to verify spark... Pull plugs on both cylinders, put the plug wire on the spark plug, hold the base of the plug firmly against bare metal of the engine (hopefully not near the PLUG HOLE as it will be charged with gas....!)
Crank over the bike briefly and observe the spark plug gap....
Sparking?

If yes, test both all cylinders. then check compression with a test gauge. Resolve what you find...Usually valves... pricey.
If no, resolve the spark issue. Also involved is a triggering system, and electronics.
I would need more information to proceed past here, but this should get you narrowed down on your issue.
Doc

Pull the plug out and test it on the frame. If no spark you need new plugs. If it does spark look at the plug. If the plug is black and wet it is getting to much fuel and flooding. You will need to adjust your carb's air to gas mixture.

Could be a carb problem or a firing problem. Use a inline spark plug tester to check the fire on both cylinders to make sure spark is there. Afterward,use a spray bottle with water in it,and spray the plug wires with bike running. If it arcs,or starts running rough,...it needs plug wires. If neither of these are the issue,then most likely you have carb problems,and they will need to come off,be cleaned and synched.

shut off the fuel at the tank petcock until the bike quits running.. then tur it back on and it should be fine....

Sticky float...

The slow circuit on one carburetor may be plugged. But bad spark plug caps could also be the culprit along with one plug being fouled. Try a squirt of carburetor cleaner in the gas line for the jets. Check the OHMs on the spark plug caps should be 5000 OHMs . If it is higher or lower replace the cap or cap/wire. Either the cap unscrews off the end of the wire or the wire is removed by unscrewing the cap on the coil.

You need a long reach plug wrench tool should have one in your bikes tool kit .

vac leak craked boots

HI harleyrider6,
No hitting means not firing?
Assuming tht its not firing up upon cranking,
please check if theres gas coming to the spark plugs and sparks too.
Not a bad idea to replace the spark plugs if they are fouled up!

Good luck.

Knight.. (Yamaha Seca XJ750A 1981)