Backfireing when ideling and when i give it some throttle

Did you replace the spark plugs. Sometimes the plugs get fouled up with the cleaners they use.

1. choke circuits still plugged up or carbs not cleaned correctly; most people that attempt to clean their own carbs do not have the proper equipment to do it with. Most carbs have really small orifice(jets) and require really small jet drills/orifice cleaners to clear them out. Cleaning them in a caustic soak tank will clean them out but the carbs must be taken completely apart or it will damage any gaskets or rubbers parts left in it. Carb cleaning should be left to professionals unless one has experience doing it.

2. Open/broken vacuum lines can make it hard to start and backfire when letting off the throttle; jets that are not cleaned out correctly can also make it backfire.

3. If the backside of the inlet grommets are not sealed at the flange and have a vacuum leak, that will cause hard starting and backfire also; this applies to carbs with a flange style grommet. If the intake grommets are cracked or leaking it too will cause hard starting and backfire. Remove the carbs, wipe the head and mating flange surfaces with laquer thinner, let it dry and then reseal the grommets back to the head with rtv silicone rubber. Make sure to wipe any excess rtv(before it drys) from down inside the port before putting the carbs back on.

Backfire when throttle down can be;
1. dirty carbs that are running lean and need cleaning. Also the rubber grommets that hold the carbs can be leaking at the backside or even dry rotted.
2. no air filter
3. broken or open vacuum lines
4. an aftermarket exhaust that needs rejetting or an open exhaust system

clogged pilot jet in the carbs causing a lean condition and backfiring

this sounds like fule starvashion blocked running jet's in carb or fule lines blocked,,,strip both and clean them out

There is a proper way to start the engine. Four controls are on your bike to assist in starting. Below are generic instructions.

• The choke, used when the engine is cold. Pull the red knob for choke.
• The " Hot Start " Lever, used when the engine is hot. Pull the lever to lean the fuel mix when the engine has been running.
• The de-compression lever, always used.
• The throttle, used to prime the cylinder, (power valve).

Don't kick, instead, push the kick lever downward. You will feel the back pressure as the piston is going upward on the compression stroke to the point the pressure is great enough that the kick lever "locks up". You are very close to TDC. NOW, pull in the de-compression lever. Push the kick lever a little bit more to get the piston past TDC. Now release the de-compression lever. Give the throttle a 1/4 turn then let it snap closed. A diaphragm, (Power valve), in the carb gives a shot of gas when this is done. DO NOT do this multiple times because you will flood the engine. Leave the throttle closed when kicking. A flooded engine will often backfire. Now give a strong kick through the full sweep of the kick start lever. Quickly get your foot off the kick lever at the end of the kick to avoid any chance of "kickback" from the kick lever. This happens in the case of a misfire, aka > backfire. It can be very painful, and can even break a leg. I am serious about that. Repeat the process (but without the throttle priming), for six kicks. After six kicks go ahead and twist the throttle again for a second priming. A good battery, a clean spark plug, a clean carb and clean air filter will also aid in starting. Note that not all carbs have a power valve. When a power valve is not present you should crack the throttle open only 1/8 inch from closed on each kick.

Either take the carbs off and clean them or add some fuel additive to clean the system. Sounds like you have a clogged jet.

Time for the carburator/s clean up, it seems the main jet/s is/are kinda blocked.

You may need to clean the carburator.Check valve clearance.

it could be a simple fule filter!