Okay, long story long, I have a 1994 Yamaha Virago 750 (duh) and I've been tirelessly working on it for the past 4 months or so. When I bought it it ran perfect, no problems whatsoever. Got it home, re did the front calipers and put a new front tire on. Went to start it. Nothing. It turned over but wouldn't run. I pulled the carbs out and cleaned them. Put them back in and it started! Great right? no. Five minutes later down the road it started bogging, it wasn't accelerating properly. Soon as I let off the throttle. Dead. I was able to start it up and try to drive it but when I gave it more gas it would bog down. Pulled the carbs out and cleaned them, and it did the exact same thing. Pulled the carbs out AGAIN and rebuilt them completely. I put them back in took it for a ride and it worked perfectly. Until 5 minutes went by cause then it starts to run on one cylinder. I barely make it back home and end up replacing both coils. Tried to start it again and nothing. It would run on starting fluid but that's it. By then I figured I should hand it over to a shop (note: I am mechanically inclined and I've worked on a bunch of motorized vehicles.) even though I knew how expensive it was going to be. Three weeks later I get a call saying my bike is fixed, I say "cool I'm on my way" and I head down there. I pay $340 for them to clean the carbs and put new needles and seats in (I ALREADY DID THAT) and I start driving away. After driving it for just a few seconds it starts to run like crap! Very scattered firing and it died on me before I got out of the parking lot. Five minutes later down the road, sounding like crap, I let off the throttle to slow down for a stop sign and it dies. Try to start it again and nothing. Ended up towing it to the shop again and they said they would look at it. A few days later it's fixed again. When I got there some of the employees had taken it for a test drive to make sure it worked fine. They get back and it sounds like garbage and we all agree that it isn't fixed. Runs off one cylinder intermittently. So I go and pick it up and take it home. It does start but still doesn't sound right but it sounds good enough, though it backfires when you rev it up. Drove it on the drive way a little and it drives fine in 1st as long as you're barely giving it enough gas to not die. If you give it more it won't accelerate and then it will for just a sec and then stops accelerating. I let it idle for a long time, twice, and let it cool down in between and it hasn't died. It will idle high for a bit if you rev it though. What is going on??? The only thing I can think of is the CDI box? I tried moving the handlebars back and forth to see if that made a difference and it didn't, I also fiddled with all the wires under the seat while it ran and nothing changed. The shop checked everything else electrical and said it was fine. I'm getting real tired of getting nothing from all my work and if anyone has any idea what is going on then I would really appreciate it.