Chainsaw Repair

Been trying to get this PR5020 to run decently for days now.
Read "all the things". Know about 1.5 turns on h & L to start, etc., etc.

1. Nobody seems to know what the T (idle) actually DOES.
It's certainly not a throttle stop like in a car. Direct fuel feed? out for more? OR
2. H&L out to lean or out to richen?
Why? Because I'm at 8600' - things are different here. - sea level settings are always too rich.
Are they fuel needle valves or
3. Will H-Jet be in effect at high RPM without any throttle?

SO - what's it doing? Nothing consistently.

Carb looks clean and near-new (chicom knockoff likely).
Fuel filter, bulb, and lines are good.
It WILL (sometimes) run "forever" at idle OR at high RPM - all based on the CHOKE.

The common explanation would be "dies on throttle up" but it's not that simple.
At this point, I've got a decent idle -- as long as the choke is closed.
The choke lever is acting more like the throttle. Open choke to go faster - WAY faster - with throttle plate closed !!
Hit trigger (throttle) and it dies almost instantly - slow pull or fast, doesn't matter.

I've played with the adj. screws several different ways, and can't really get any "reaction" to the changes.

Thanks for reading!

Great info! Thanks much!

I assume you meant 3000'MSL not Feet Per Second. 
That's key info.

3000' is the low point of Colorado, and we're 3 times that high.
1/2 mile above sea level vs. my 1.5 miles above sea level.

In engine terms that's a 10% loss of power vs. a 25% "derate".
In straight oxygen/pressure levels, 2.3% less than sea level vs. 6% less.

It's not a linear progression, and the screw settings won't be either,
but now I know it's going to take much bigger swings at it than I was doing!!!

As a retired FF/EMT, I'm more familiar with altitude effects on fire & humans. 

Will report back when I know more.

Ahhh! - I get it now !!

I looked at his profile -- yes, his location is a touch more than a mile high.

And, I do appreciate the 3000fps --
I have a couple of things that can do that, too.