just bought a quannon. having issues

[DiffieMcDermit]

Just bought the bike 2 days ago. While starting it it idles pretty low and almost feels like it's gonna die. When I put it in gear and start to release the clutch and go on the gas at the same time, the bike stalls 60% of the time. It only goes 55mph . But when decelerating it backfires.

What would cause these issues?

[BettinANDlosing]

Idle and stalling sounds like a dirty carb. Pretty easy to get ur out on the Quannon. Highest speed I've gotten on stock ones as about 68 indicated screaming almost 10k. 55 is low. Check your tires maybe? Worn chain? Previous owner change the jetting?

[DiffieMcDermit]

Yea he did say it was running rich. So I kinda thought it would be that the float is to low. Which would cause it to backfire while decelerating.  But doesn't explain the low idle and top speed of 55mph. It has a brand new rear tire. He did say he just switched out the jet and lowered the sprocket. The bike only has 2300 miles and it's a 2010 he also said he hasn't riddin it in over 6 months due to cold winter here but it was stored in a garage.

[BettinANDlosing]

Yeah for sure clean the carb, it sounds like he didn't use it. Also he went down a size on the rear sprocket or front sprocket? What rpm are you turning doing 55? The bike might not be enough power to pull higher gearing.