Cold start troubles: The little Stihl 011 that couldn't.

[McCullochKid]

Here we go again with another thread about this little monster...
Long story short, I acquired a Stihl 011 that appears to be low use and in great condition, but it will absolutely not start when its cold. You need to prime it to get it going.
First place I checked was the carb, which I cleaned out thoroughly with my ultrasonic cleaner and put a new kit in. This helped things once the saw's running, but unfortunately did little for cold starts.
So I've moved down the line and gave it new lines, new fuel filter, made sure that the tank vent does its job, and checked the piston and cylinder, which are pristine and test at about 158-164 PSI.

You can pull the cord all day long when the saw is cold, with or without choke, and it'll never start. However, once you've primed it once and started it that way, it'll run and cut beautifully, and when things are warmed up you can restart the saw on the first pull every time.
I'm thoroughly stumped here. At this point, I really want to get this fixed just so I can pass the saw on and get it out of my sight.
Any suggestions or little tricks I can try in an effort to diagnose what exactly is going wrong?

 

[rupedoggy]

The choke is not closing

 

[L34]

Dad has an 010 that you have to put your thumb over top of carb to get it to start.
Yes it has a choke problem but just as easy for him to do this as saw is not often used.

 

[HarleyT]

If it has a cheapo aftermarket air filter,
it won't choke properly.

 

[Old2stroke]

Choke must be completely closed and throttle partly open. Very few 2-stroke engines will start with a closed throttle when cold.

 

[merc_man]

My 009 was hard to start( i think ther pretty much the same saw) when cold too. I turned the low jet out some and it really helped the cold start.

Sent from my SM-G950W using Tapatalk

 

[McCullochKid]

The choke is not closing

Dad has an 010 that you have to put your thumb over top of carb to get it to start.

This must be it. I just went out and tried the thumb trick, and on the very first pull I had some fuel on my thumb. The next pull started the saw just fine on its fast idle.
Currently letting it cool back down before I try experimenting some more, but now I'm wondering where to go from here.
It already has an original Stihl air filter on it, so that can probably be ruled out.
The type of choke on this 011 is a switch that you slide forward, which pushes down a little piece of plastic on top of the air filter/carb. It's obviously not sealing it properly, but why?

Think I could attach a thin piece of gasket or other squishy material to the plastic part to help it seal better?

 

[HarleyT]

Put up some pics, especially of the air filter.

 

[L34]

I glued an oring on my old orange 009.
Made it choke a lot better.

 

[McCullochKid]

So guess what? After using the thumb trick, the 011 has now decided that it wants to work properly.
I've tried multiple cold starts now that run on the second or third pull off of choke, just like how it should work.

I'm almost wondering if there was an air bubble somewhere in the fuel line or the carb, and the little plastic choke piece just couldn't provide enough of a seal to work it through the system.
Then again, you would think such a thing would have worked itself out when starting it via priming.
I don't know, I'm just glad it appears to be functioning properly now. I think this saw is out to make me look foolish. If it starts acting up again I'll revisit the air filter and/or stick an o ring on the plastic piece like mentioned by L34.