MS440 high rev then dies

[The Snowman]

Newb,
Original owner of a MS440 thats 23 yrs old. Light duty, firewood mostly.
Was dying after a minute of idling before I messed with it. Got all the vibration bushings so I figured I'd take it apart, clean everything and replace those.
Well, got stuff clean, back together, had starting issues. Eventually flooded to where I couldn't pull it. Pulled plug and gas dumped out cylinder. Ordered walbro carb rebuild, cleaned and replaced gaskets/diaphragm.
Now itll start, idle sometimes. When you get that high rev from half choke it spins up then dies, or if you get to idle and feather up to high rev that kills it.
Did I miss something?
Oh yeah, took apart and cleaned tank vent too.
Carb is set to factory settings on side cover: L 1/4, H 3/4.
Not sure what I screwed up.

 

[J D]

Thread 'MS440 carb initial settings, limiter caps ???' https://www.arboristsite.com/threads/ms440-carb-initial-settings-limiter-caps.44077/

 

[The Snowman]

Thread 'MS440 carb initial settings, limiter caps ???' https://www.arboristsite.com/threads/ms440-carb-initial-settings-limiter-caps.44077/

I believe those were still on there.
Maybe get time to pull them off later this week. Got friends tractor here now so gotta take advantage of that first.
Thanks

 

[J D]

Yeah, you kinda need to pull them to get the L & H screws out to clean the passages.
Did you pull the welch plug?
Did you set the metering height?
Did you check for leaks & pop off pressure?
Are you sure the gasket & diaphragm are round the right way?
Did you blow it out with compressed air?

 

[cookies]

check the impulse hose, sounds disconnected or torn

 

[stihltech]

It is 23 years old. Time for vacuum and pressure testing. It may be lean due to air entering after the carburetor, You cannot adjust this out.
Verify sealing before blaming carb. I with the statement about the pulse hos. Seen more than 1 pull off and/or leak at the carburetor nipple. Then-
Intake boot
Seals- both suspect at this age (same with me).
Lots of cylinder gaskets.
Oil pump worm adapter sleeve. Fill the backside with grease.
That is a start.