its like the 4th of july every time I ride!

so, like I said. my 77'650 pops like crazy when I ride it. I have taken carbs off and cleaned (lemon soak and carb cleaner) it was a bit better after that but still backfiring. I removed all the gas and put new in line filter, still no change.
where do I go now fellas'? point me in a direction a I will try it out.

Backfiring usually means you have too much unburned fuel entering the exhaust port or exhaust pipe. Maybe you should check your timing.
Grant.

ok. I do have a manual but is there any tricks to checking the timing that I should know.

Try increasing the amount of choke you give the bike - if the popping descreases or stops, then you've got a vacuumm leak somewhere and it's pulling in to much air.
Likely culprits are the intake manifolds which become rock-hard and brittle over the years, and most often the hairline cracks causing the vacuumm leaks are very hard to see.
With the bike running, sray some WD-40 or carb cleaner at each manifold individually (change in RPM's indicate you've found the leak). This will help give you a better idea of where the prob is located.

Look at the ports on the carb manifolds for cracks,the rubber plugs dry out and crack. Z1 sells new ones.

If the backfiring is consistent under most conditions, and not just when you close the throttle, I would check the power to the coils. You may have a flakey wire or a bad connection at the ignition switch, kill switch, or even at the fuse holders. The unburnt fuel builds up in the exhaust while the bike is no firing, then when the bike resumes firing, the fuel in the exhaust goes off like a fire cracker.

Could also be worn out points, too. Check that first.

will check those. sweet tricks. the bike acts the same weather I have full half or no choke though.

the backfire is when I get on the throttle not on close throttle.

May also be the coils.
May also need to check the voltage while riding.

Temporarily, as a test, you could run a wire directly from the battery positive to the coils. Put a switch in line. Make sure the battery is fully charged and has a good ground connection to the engine (if the starter works, the ground is probably good). If it acts the same, then the problem would be narrowed down to coils, wiring from coils to the points, or the points themselves.

If not already done, would also assure valve clearances being within specs.

Good Luck!

I had the same situation on my 1979 KZ650 (way back when), and it turned out to be the reed valves that inject fresh air into the exhaust. I was advised to block off the aforementioned reed valves, but I do not remember how I did it. I’m rather certain that there’s an article here that describes their removal / alteration.

Labeled number 8 on the image...if it comes through!

Hope this helps!