2007 rancher 420 trx

[Fastfreddy 0]

Hey guys  I have a Honda 420 rancher starts right up runs fine idles fine. if you ease on the throttle it will Rev fine.  but if you hammer it it bogs and backfires I’ve change the fuel pump fuel filter same thing nothing changed oh sorry I also change the spark plug. Can someone help 

[retro 4,048]

Welcome to ATVHonda Fastfreddy!

 

Does it act the same when the motor is cold as it does when the motor is warmed up? Are there any airbox mods on it... or have you added a snorkel onto your '07 420? Are the valves in adjustment? Is the ambient air temp sensor on the airbox plugged in?

[Fastfreddy 0]

The sensor is plugged in yes it acts the same way hot or cold. No mods all stock. And no valves have not been adjusted. 

[Fastfreddy 0]

Could the idle air sensor be bad. Someone on another forum said unplug it and if it doesn’t act any different that it could be bad so I unplugged it and it ran the same. 2007 rancher 420 trx

Edited November 22, 2020 by Fastfreddy

[retro 4,048]

Yes, the IACV may be dirty. The throttle body may have standoff/sooty buildup inside as well. You can take the throttle body off, open the throttle butterfly and clean the bore with some Berrymans carb cleaner in the aerosol can. The IACV sensor is held on by tamper-proof screws so you may need to twist them loose with a pair of vise grips or whatever ya got handy to turn those screws. Once the IACV is off you can spray it with Berrymans to clean it while rotating the shaft back & forth. Put it back on the throttle body exactly where it was... let us know how it goes!

[shadetree 5,880]

injector can also be dirty/clogged.