Need to know if my bike is injected or carb ? 2004 vulkin clasic 1500

A single dual throat throttle body (fuel injection)

http://www.bikebandit.com/oem-parts/2000-kawasaki-vulcan-1500-classic-fi-vn1500n-throttle/o/m149531sch65727

its fuel injected and mine does the same thing for backfiring. as for half throttle. you closed the choke after it warms up. and might need to check the air cleaner maybe the plugs need to be changed. not sure.

It would help to know what your bike is?????????? You could be losing fuel, is it carb or injection, could be piston rings, so many things but you omitted the make model????

ADDED NEW EXHAUST LATELY? SOUNDS LIKE CARBS NEED CALIBRATING. IF BIKE SAT DOWN FOR THE WINTER OLD GAS CAN SOMETIME GEL IN INJECTION SYSTEM. RECALIBRATE CARBS AND CLEAN INJECTION SYSTEM SHOULD DO THE TRICK.

Anytime you change the exhaust system on a bike, it's going to affect the mixture. I know nothing about the fuel injection system or the computer on your bike. That being said, I'd take the bike to shop that had a dynometer and a competent mechanic running it. They may need to make some changes in the fuel map. It's probably running a bit lean in the low RPM range. That's my best suggestion.

Good Luck
Steve

Could have air leak between carb and head (intake manifold), or carb may need adjustment.

Has the bike been setting up for awhile? If so, it problably needs carb and carb jets cleaned.
try SeaFoam, Lucas, or other good carb and Fuel injection cleaner added to the fuel. They are a petro base additive, so you can't add too much. With the ethanol that is in most fuel now, bikes cannot be parked for very long without gumming up.

Black smoke is usually and indication of a rich mixture. Now, you didn't tell me whether your bike was carburator equipped or fuel injected. If carburator equipped, is the carb the stock carb or has it been changed. Still, regardless of whether its carburated or fuel injected, the mixture is way rich when revving. If the bike is equipped with an S&S carb, this is typical and it has an adjustable accelerator pump and most people get them adjusted too rich. Find out whether your bike is carb equpped or fuel injected and let me know. We'll go from there if it's carb equipped. If it's fuel injected, you'll have to take it to a dealer.

Ride Safe
Steve

Issue with your Timing Advace need to be re-ajuste Carb need tune up also.. Check Spark Plug for bad performance.. Take a carb calibrator to ajust those Carburator.. nice but Touchy You will get the best performance and you will save much more on gaz...If it persist ..Well your Valve as to be check' Up

Replaced old gas then i am assuming the bike was not used for some length of time? If you have old gas in the tank and the bike was not used the gas in the carbs would have gummed up the jets in the carb or carbs.
sounds like its time for the carbs to be cleaned.

is your bike fuel injected? take a look at vance and hines web site as well a the power comander web site as the have fairley easy to install ecms to give you more smoother running bike. if its carborated may need to clean and adust carb or rejet