I have heard of people doing this and I think you have to take out the gears on the shift motor. I also heard that they won't hold up, because the transmissions are, somehow, different between the ES and S models. They say they won't handle the strain. The explanation that I got, was that the shift motors shift with the exact same amount of force and pressure every time and on the foot shift, when you shift with your foot, the pressure varies, so the foot shift transmissions are built different or better to compensate. I have never tried this. This is just what I've heard and I am simply passing it on to you. You might call your local Honda dealer and they might be able to tell you if this is true or not.
Most 4-wheeler problems are caused by a loose nut connecting the handlebars and the seat!!
You only need two tools in life -- WD-40 and duct tape. If it doesn't move and should, use the WD-40. If it shouldn't move and does, use the duct tape.