Quick question regarding backfiring???

[Len Todd]

So had it to yamaha today had 170 jets put in red cv springs and kn filters put on with pre filters and a crank case filter, clutching all done and it still has the little back firing oh ya new plugs too! He didnt have # 10's in stock so he just put in # 9's instead!! I put 20$ worth of fresh regular gas in it and he told me once i start to run it a bit it should come out of it, and he said throw some seafoam through it too!!

Backfiring is most often casued by an exhaust leak, TORS activation or chaffed wiring, typically up buy the CPU.

 

[happy1426]

no exhaust leak i just put on a new flex pipe and 4 new donuts grounded the clips of some to make them tighten up more new muffler mountain performance and tighten the #*$&@ out of everything! cant see wiring if it wasnt doing it before the exhaust!

 

[jsjk-4-stroke]

there is a carb switch under the idle adjustment screw mine would work sometimes and then not work it will set off TORS a little check it with a ohm meter to see if it makes & breaks everytime you open & close the flipper