still won't start :(

[krypto35]

GS still won't start.  Let out 1 BIG backfire after 5 minutes of cranking and pausing and cranking.  The bike is a '95 with V&H exhaust, K&N Lunchbox filter, 40 pilots and 150 mains, and 3,000mi on the engine. 

Never had it in solid running condition.  When purchased it would backfire a lot and not start.  A friend got it to run once, we both rode it - was very rough a sounded rich.  The other week I had it running OK but once it warmed up it would backfire into exhaust a lot and high-rev randomly, which is when I found out it only had 40 BLEEDER pilots and 142.5 mains it - the bleeders are incorrect for the carb and the 142.5s were too learn - so as of today they were changed to regular 40 and 150s.  I pulled the plugs and they were wet (getting gas), and they both sparked bright blue/white, and the gap is correct.  Plugs are somewhat black and seem to have oil as well as gas on them - could my rings be shot already?!  I know one my other GS, new plugs changed everything and it starts instantly when I hit the button, so plugs are in order for tomorrow.  Any other help or suggestions would be appreciated!  Thanks

[poolshark]

Compression test it. Oil on the plugs = bad, bad, BAD.

[Jughead]

Yeap do a Compression check and go from there.Of course it sounds like your Flooding now.Your Plugs may be fouled out. Take the Plugs out and turn the Motor over a few times to dry the Excess Fuel out of the Cylinders and Install new plugs.