3120XP trigger lock question

[PogoInTheWoods]

Got most of the parts I ordered for a 3120xp project and am now in rebuild mode. 'Bout as straightforward as it gets except the little trigger lock pin assembly (high idle, throttle catch, whatever you want to call it) has me sorta stumped. Can't find anything definitive explaining how it actually fits into the handle, where the spring goes, etc. It's currently rednecked together and works but was also popping into high idle position on its own occasionally when the throttle was held wide open. I have the correct parts but could use a good pic of what this should really look like when assembled (or a concise explanation of how it goes together correctly with the right parts). Pretty sure there is a small machine screw missing from the OEM kit that would secure the knob to the post which in turn would secure the spring between the trigger and the knob....
Don't see one in the IPL, though. And the inside of the pin doesn't seem to be threaded, either.
TIA for any help.

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[Adamski]

Not sure if this IPL is of any help, looks like the pin goes from the right hand side and the boss from the recoil side, not sure how the spring fits into the equation though..

Maybe the spring goes between the trigger and the left hand side (between the trigger and the boss) to keep the trigger tight against the handle plastic?

Meh....

 

[Adamski]

Like this, excuse the wobbly sketch (a mouse is terrible at annotations)

 

[PogoInTheWoods]

Nothing there to hold the spring in place that I can see, though I did consider that approach. Pretty sure the boss (knob) holds the spring in place on the shaft. Just not sure what's supposed to hold the boss in place to hold the spring in place.

Thx for the input.

 

[PogoInTheWoods]

bump...

Still scratching my head over this.

It was suggested elsewhere that the boss (knob) is secured in place by spreading the shaft (pin) end with a punch. Problem there is lack of length on the shaft itself to spread or peen the end and nothing to support the large end of the shaft if you whacked it with a punch or drift anyway.

Anyone?

@Spike60 maybe? (mayday!)