So my 96 crb600f3 is no longer starting.
I tried with multiple choke settings to no resolve.
after few start attempts it will give me a small backfire.
I road the bike a few minutes yesterday I don't know what gives any suggestions?

 

Sounds like the issue I had a few weeks back when I flooded mine on a cold morning. I drained the floatbowls, removed the plugs and cleaned them up, and got her to start after that. Just a thought.

 

after i posted that I went out and tried again. Choke fully closed throttle 1/4 and it started let off throttle opened choke and died again. Tried again throrrle 1/4 started I noticed while revving it it didnt feel or sound the same as if I were losing HP somewere I had to turn the idle controller up to get it to idle but still didn't sound or feel right. Took it around the block a few times felt minor shakes in low RPM and still didnt sound or feel right. Not sure at all what is going on.

I did notice some issues the last few weeks but had no performance loss.
I changed the oil which looked like it had missed 4 changes from the previous owner oil was BLACK. I put in 20-5 oil(i live in Florida.)
took a look at 2 of the spark plugs (far left and far right) both of which were black and a bit damp.
I cleaned em and placed them back.
I also have sea foam (little less then half can) and 93 gas in there which I noticed didnt seem to be fully burning(exhaust was spitting out small amounts of gas)

The bike ran fine yesterday and the past week despite all this.

 

93 gas isn't helping, the engine doesn't need it, and also it burns slower so that's why you're getting gas out the exhaust. 87 burns easier and is actually what they're made for, though you may need to run 89 if you have carbon build up or anything else that causes pinging.

 

its probably fouled from too much choking and idling. its really hard with these bikes to keep them running great by starting them and not get any revs out em to warm everything up. a couple times into the 8-12kr pms will clean up a slightly fouled plug. the seafoam and 93 are working against you also. if you can get it started take it out and crank on her and see if it will clear up

 

+1 if she starts up take her out for a good long ride to clean her out

 

Don't start your bike with throttle. Whatever is wrong, you're making it worse. You're likely to foul the plugs on top of whatever is causing her not to start.

Bike should start, even in cold weather, with just choke. Based on what you described I'd ask when the last time your carbs were cleaned. That'll be after you resolve the plug situation (are all 4 salvagable?)

 

did ya follow up like kuro said and pull a plug out to the side and test each plug?

If you replaced em, make sure they are all gaped right.
Make sure there is no blockage in your carbs as well, sometimes debris can prevent your bike from turning over, but she sounds like she is drowning in fuel.

 

When it's really cold (25 or less), I use just a smidge of throttle with the choke. It doesn't take but maybe a 1/16 turn.

 

toss a little starter fluid in there. that sure would get it started up and the choke should keep her on. does it have a manual cct. this happened to me a while back. the low speed jerking and studduring when i had the stock cct. and adrianinflorida you bike looks fantastic.