I have a Brillelli 46CC that just had an accident and the sping that use to close the carb (move the throttle back after it is opened and released) is not working, I noticed in Bob's post he said
"Remove and toss the "stop screw" on the throttle arm plate, then unhook the little spring that pulls the butterfly closed, unless you want your throttle servo under constant load/tension. Do NOT REMOVE THE SPRING."

So, do I not need this spring to close the carb anymore, just leave the spring on and go, is this what it means? Just trying to understand if it will be ok not to have the spring closing the throttle anymore or if I have to fix it. The spring is still there, just doesn't close the throttle anymore.

Thanks,

Chuck

You are fine...the spring helps keep the plate centered in the carb bore. Without it the vibrations could eventually wear the mating surfaces and cause problems for you. Leave the spring, don't worry about it no longer closing the plate

It is not the end of the world if the spring doesn't work.

Many people un hook the spring anyway. Others leave it hooked up.

It is up to you

That's right. Simply clip the hook end of the spring off and leave the spring in place. It keeps the butterfly from vibrating around - possibly messing up your mix and causing premature wear. If the spring is left stock, the servo has to work against the spring pressure every time you open the throttle - drains the battery.

Yea, dump the "stop screw", too. Let the servo determine the low end position. If the servo stalls against the "stop screw", you'll either bend linkage or drain the battery - fast.

CAUTION - If you remove the butterfly, be absolutely sure you reinstall it in the same position/orientation as it was.

Hey thanks for the help! I will just leave the spring as is and not worry about it. Thanks a million.

Chuck

I see lots of comments regarding the spring, and stress on the servo in various threads. Those curious should fit an amp meter between the throttle servo and receiver, measure the current draw with and without the spring catch on the arm I've only seen a select few carbs with significant spring tension on engines we use. The difference, if any noted at all, isn't worth removing the spring catch from the arm, in most cases.

My vote is with arobatx. If the arm is long enough for good throttle resolution, the spring tension is minimal. Besides the throttle is almost in constant motion, so the tension rarely sits against the arm in a stalled condition. That being said I have some engines done either way. Kind of depends on how I feel the day I hook up the throttle.