has anyone had to have there 07 420 computer reset? the local atv shop told me that was a common problem with these new ones. mine is backfireing now an wont crank.when it was running the idel wasnt very smooth an it acted coldnatured. i havent even ran a whole tank of gas thru it an im having problems already. any suggestions??

 

Any 420 that leaves our shop gets the ECM reset and a health check done to it.
Make sure you wait for the FI light to go out before starting your quad. This gives fuel pressure time to build up. I have seen them act like yours is when this is not done. Also make sure the fuel petcock is not partially turned off.
A few other issues that may be the problem is a fouled spark plug or a sticky IACV. A quick check of the IACV (top of throttlebody, rearward of where the throttle cable enters the throttle body, IAC has a plate holding it to the throttle body with 2 tamper proof torx head screws on it) Turn the ignition on and listen for the IAC to beep. This is normal and it should be working correct. Also the IAC valve can be removed and cleaned. A shipping coating (cosmoline) may be hanging the valve up from working correctly.
I would suggest having the ECM reset, then following the proceedure let the unit idle for 10 minutes warm, 15 to 20 miniutes cold so the ECM can aknowledge all inputs of sensors and ranges so they can operate together correctly.

Hope this helps you

----- Gimpster -----

 

thanks ill check on that stuff an see. the bike when its running is great but this lil problem today isnt helping nun. its making my 14 year old 300 look better. maby the 420 will straiten out