2000 suzuki marauder vz800 loss of power and more?

[Matt]

Having some power problems with this bike. Bought it one month ago and was working great for the first week. After that i had to replace the chain and the shop that did it told me the bike was only firing on one cylinder. It usually only did that when it was cold and low throttle. Once it was warm, it would ride fine.. But slowly it started to get worse, till one point where it was cutting in and out a lot more and more noticeably. I determined it was the front cylinder that is where it was cutting in and out, so i removed the carb and cleaned it out and reinstalled. When i fired the bike up, both cylinders seemed to be working just fine. But now im not getting the full power i had before and when it gets warm, it seems to be doing the power cut in and out (mostly under low throttle), and the bike has a kind of flubbing sound (like when you make a raspberry at someone, but less spit sound) out of the same cylinder i was working on and you can hear it well when you are decelerating (no throttle coming down from high rpm) it kind of sounds like a compressor.
I know this might not make too much sense and im not too familar with motorcycles to tell you what that sound is, so please bear with me.
But I cant really spend anymore on it right now so taking it into the shop is something i cant do for a while.
Any thoughts?

I did take the fuel pump off earlier today and cleaned it out, didnt look bad inside and no particles came out of it. still has the same problem as before i did this.
obviously i have spark to each plug or it wouldnt cut in and out, it would just not cut back in.

 

[Mitchell]

take the carbs off and check all of the jets it may be a slow jet that's plugged, this is the smaller jet as there should be two of them in each carb, also check any fuel filters if they are plugged it could cause this, one more thing check the vacuum diaphragm that allows fuel to come out of the petcock if it has a hole in it, it will send fuel down the vacuum line causing it to run terriblely