EXCAP232,
I don't know how to mount the supplied throttle arm leaving the spring on--it won't fit. Perhaps are carb setups are different. Pukinbuzzard basically said the same thing-arm won't fit. I didn't use the washer under the arm may give this a try. There is a pic in the rcshowcase user gallery where the installer uses the stock linkage with the throttle servo right near the firewall. So I guess you can leave the spring on if you want.