So my bike idles great but when I rev it up it starts popping and kinda wants to quit what would cause this am I pushing to much gas through it I'm gonna take the carb off and clean it so it will be no issue to re-jet it's an 83 rebuilt with a s&s carb any suggestions on what size jets to use

 

Are you reving it up at idle or when you are riding?

Is it popping out the exhaust or out the carb?

First thing i would do is check for intake and exhaust leaks ...

Intake And Exhaust Leaks Tests

You cannot get a good tuneup if there are intake leaks or exhaust leaks.

1. Check for Intake Leaks

With the engine idling spray propane gas or WD-40 around the carb/intake/cylinder head joints. Propane is best because it leaves no mess, and is most easily sucked in thru leaks. WD-40 is said to work well because it has very fine spray droplets. Be careful to not allow any of either to get sucked in thru the A/C as this will invalidate the results.

Any change in engine RPM is a leak which must be fixed.

EDIT: Experience is that this procedure will identify larger intake leaks, but it may miss very small leaks that also must be fixed. And that propane is the better choice.

EDIT: You have to do a lot of spraying to detect a small leak. Propane will be really clean. Anything else like WD-40, carb cleaner, etc will make a mess.

2. Check for Exhaust Leaks

Pour about 1/2 ounce of oil into each cylinder thru the spark plug holes. Run the engine at idle. You will get lots of smoke for about 5 minutes.

All smoke should come from the ends of the exhaust pipes/mufflers. Any other is a leak which must be fixed.

 

When I go to take off it wants to die out that's when it backfires out of the exhaust

 

I think Mick is right, intake leak. Since the rebuild has the bike ran good?

Here is jetting recommendation out of a S&S manual. You can go to S&S web site an get this information. A good way to check if you have the right inter. jet is too go by the air mixture screw. It should be at about 1 1/2 turns out.
If the engine runs best with the mixture screw turned out less than one turn, the intermediate is too large. If it is greater than 1 3/4 turns, intermediate probable too small.
Do what Mick said first, there can't be no leak in the intake.

 

Your jet size will also detremin what altatude you are at ,this is very inportant,here in costa rica i am at 5000 FT and had to down size my jets agreat deal,i have a mikuni carb and had to go from a 330 jet at 600 ft to a 220 at 5000 Ft. But i think your problem is an intake leak,put electrical tape or hockey tape around you intake ports,where the intake manifold attachs the motor and connects to your carb.Ihad the same problem and this cured it.