Does anyone know how to increase the idle on the FI 420?

 

My idle has always been fine, so this has never come up for me. Thought maybe the owner's manual would say something, but a quick look at it and I didn't find anything. A service manual will tell you for sure, or just pop in and ask the mechanics at your dealership.

 

The EFI system on the 420 does not require or allow for idle adjustment. However the 4 items suggested in the manual that would effect idle are:

throttle operation and or throttle lever freeplay

intake air leak

engine top-end problem

IACV operation

I think it was HondaMechanic that had a piece on here about how to clean the IACV.

You might search on here for IACV.

 

If the MIL light isn't flashing then I would check the IACV to see if it was stuck open ..

 

On EFI Rincons the IAC has been known to get sticky, usually happening in cold weather, and resulting in too slow to keep running, or more often very fast idle once warmed up.

The solution is to take the IAC valve off and spray it clean.

 

This a brand new machine, I just thought it may help with the backfire that these quads are known for. When going up steep hills and then going down right after the backfire will occur unless I give it a tinny bit of gas as to increase the idle. The quad has 100 miles and 15 hours on it.

 

The backfire will go away, when the exhaust gets sooted up a little.....