Motorcycle Repair: Lean plugs and popping, but only lately, exhaust gaskets, vacuum line

Question
Hi Mike,

Need to address a problem with my bike and I'd rather do it myself, local dealer shop just threw gas at the problem and I like knowing what/how everything on my bike works anyway. Just found this site and figured I'd take a shot.

Had my bike in the shop to have something on the fork checked, asked them to also look into the way it was running. Stage 1 88ci Night Train (fuel injected), K&N filter, V&H staggered big shots and a race tuner. Had the race tuner installed last year when I needed a new ECU, bike ran like a top (it was September, pretty similar weather to what we have now). No pop on decel, no cracks, etc. I ride year round, it's seen weather from low 90's and humid to low 20's and dry. It's been fine up until last month late last month. Lately it's been popping quite a bit on decel, sometimes a loud crack. Also noticed I can hear a much more pronounced hiss around the intake area (haven't heard it in 14,000 miles, now it's as plain as day, don't know if it's just TB hiss or not). The dealer shop replaced the exhaust gaskets and "recalibrated" the race tuner to richen it up. Still popping/cracking quite a bit, more so when it heats up. This is what makes me think it's not just a lack of fuel. Also notice what sounds like a slight muted pop sound now and again when idling or at zero TP. I'm guessing I have a leak somewhere and I'm going to check it out soon. I'm thinking intake leak, or maybe a problem w/ the vacuum line?

Would just like some feedback if I'm on the right track/other things I should check. I tend to ride on the harder side, I'm not much of a putter...Haven't noticed any drivability problems, but the fact that the sound just up and started makes me thing something is wrong (or on its way to wrong). Not to mention the popping is damn annoying.

Thanks in advance, and sorry for the long message.

-Jimmy

P.S.--where are you located in Ohio? I live in VA but originally from PA near the Ohio line. Looking into possibly moving to the Columbus area.

Answer
I am located in Mount Victory, Ohio, which is about 50 miles from Columbus.
As to your problem, I would check the intake manifild for leaks. If they are ok, your hissing might be a blown head gasket. Start the bike and run your fingers around the head and you should feel it.
Good luck and happy riding
Mike