What fell off my engine?

[scatteredsun]

Got my engine mounted and running. Last thing I did was connect my throttle.

It was idling along and I heard something fall. This scew/spring thing was on the ground. Not sure where it came from and I don't see any obvious place it came from. Looked in the manual and didn't see an obvious match.

 

[scatteredsun]

420cc predator BTW

Sent from my SM-G900V using Tapatalk

 

[frostyflammable]

Looks like just the throttle stop screw. Screws in so that it hold the throttle handle from opening all the way. Look for a threaded hole very close to the throttle assembly.

—Dan

 

[mckutzy]

That is the throttle arm stop...

 

[bob58o]

Is that needed to prevent damaging the butterfly?
Or can he throw it away?

 

[itsid]

it's the "low" end stop...
it's the goto solution to quickly adjust the idle speed
(by opening the butterfly a hair)

So no, he should keep it

'sid

 

[bob58o]

it's the "low" end stop...
it's the goto solution to quickly adjust the idle speed
(by opening the butterfly a hair)

So no, he should keep it

'sid

That sets the limit for "max" throttle (absolute max throttle is Fixed by the tab cast onto the carb).
Low end throttle stop is the idle speed adjustment screw on the carb (absolute min throttle is Fixed by the other tab cast onto the carb).

I was wondering if removing the adjustable max throttle stop might bend likanges or crack plastic butterfly valve components by pulling/pushing too hard against the tab on the carb.

 

[itsid]

Oh right.. I'd sworn it'd sit the other way around..

In this case... it doesn't make much sense on a go kart/mini bike ..
the aforementioned tab should keep the butterfly at 90°
the only thing that scew would do is to adjust that in case the butterfly overshoots slightly
(which frankly on chinese cast carbs is a possibility )

since frankly limiting the throttle is likely unwanted
(and even ruining the clutch in case it's set way too low)

So I'm a bit biased towards keeping the screw in (and set up properly)
but I don't think you could actually damage your butterfly if it gets lost.

'sid