Wont start, Loud exhaust Backfire! Help

[eran_k]

Yes,
now i need to figure out why it will only idle with the choke pulled 3/4.
i guess it's running lean but will replacing the main jets effect idle or idle is adjusted just with the pilot screws?
My needle is adjustable as well so should i move a slot or two down?

[Badooka]

Good- always troubleshoot the very basic items first- ALWAYS
Sounds like your main jets are gunked- it doesn't take much time at all for deposits to start with this modern gasoline. You need to completely tear down, dip and rebuild those carbs. It's a little labor but worth every second of it. Bike will run like you won't believe.
The trick is to never let your carbs gunk up again when you get them done.
Small amount of Seafoam, Marvel Mystery oil or STP's new fuel additive will save you.
Modern fuel in carbs need to be conditioned unless your burning through every tank.
Deposits will begin after just a few weeks of sitting untreated.
See Basscliff's site for Carb teardown info.

[terrylee]

If like all my bikes should have idle screw in middle of carbs facing towards back of bike. Turn right to make idle higher, left to decrease. But as was said if you have not cleaned carbs. properly you're just chasing your tail. I would recommend bench synching when done and then synching with proper tool once it running. Also if you haven't adjusted valves should do that before final synch is done. terrylee