Butterfly screws

restornator

Petty Officer 1st Class
Joined
Aug 15, 2009
Messages
361
Why are they so hard to install? i'm talking about the screws that secure the throttle and choke valves to their respective shafts
 

a70eliminator

Captain
Joined
Sep 9, 2007
Messages
3,762
Re: Butterfly screws

Those screws get staked after they tighten down, it assures they can't vibrate loose fall out and get sucked into the engine.
 

tootallofwa

Petty Officer 2nd Class
Joined
Feb 20, 2010
Messages
178
Re: Butterfly screws

Why are they so hard to install? i'm talking about the screws that secure the throttle and choke valves to their respective shafts

When trying to start a potentially cross threaded screw, I turn it left-loose first till it sets into the thread before turning right to tight. Turn slowly left and feel it settle before tightening. Or replace the screws with new ones.
 

F_R

Supreme Mariner
Joined
Jul 7, 2006
Messages
28,226
Re: Butterfly screws

Those staked screws are not supposed to be removed. If you do remove them, it destroys the butterfly shaft and it has to be replaced. You can't get the old screws started because the ends are buggered up by the staking process. Even if you do get them back in, there is great danger that they will vibrate back out and be ingested by the powerhead, Result: Destruction of the powerhead.
 

restornator

Petty Officer 1st Class
Joined
Aug 15, 2009
Messages
361
Re: Butterfly screws

i was afraid of that. fortunately i may have a spare body with the butterflies in tact
 
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