Not starting and backfiring

So i just cleaned set the float lvl on my carbs, put them back on so i can snyc them and the bike started right up. Turned it off to put the tubing on for the sync and now it wont start just backfires. Any thoughts?

 

Prob not clean enough, as sad as that might sound. Probably something simple but then again, there isn't much simple about these carbs. just keep cleaning, replace anything even a little worn and then bench synch...oh and make adjustments for any mods.

 

So i cleaned the spark plugs and it started right up, when i went to bench sync the needles on the gauges just went crazy and no matter how i turned the adjustment screws they still did the same. I put the colortuner on and tryed to adjust the yellow flame and still same result i turned the fuel screws and the yellow flame didnt change. And now it wont start again....Im out of ideas i dont know what to do

 

You are probable way out of adjustment now. If the bike is stock, turn the mixture screws to 2.5 turns out, and check your bench sync again. A really quick and good way to bench sync is to look at the tiny hole in the top of the carb throat. adjust sync screws until they are covering just half of that hole.

Also, what kind of sync gauges are you using? Some (like the dial gauges with needles) have to have a restricter inline to "baffle" the vacuum feed. Also, make sure you are getting a good seal from the vacuum tubes on the carb boots.

If it will not sync ( bike should be fully warmed up before attempting), then you likely still have dirty carbs of faulty components in the carbs. it is also futile to try to color tune the plugs until the sync is good.

First and foremost, have you checked the valve clearances and are they in spec.

Order of business:
1) valves must be in spec
2) insure good plugs and that they are the proper ones for the machine.
3) carbs should be in perfect working condition, and float levels verified via clear tube method, and bench synced.
4) perform running sync with proper sync gauges or manometer. (you do not have a YICS model bike, so no port blanking needed)
5) colortune
6) keep tweaking 4 & 5 until all 4 cylinders are well balanced, and idle mixture is spot on.

Then for ultra fine tuning, do 4k + rpm plug chops to verify main fuel mixture.