HSSK50 - Hopefully a simple carb question

I need to adjust the carb - it runs lean - I attached a couple of photos.  I presume that the adjustment screws are below the caps indicated by the red arrows?  Can I drill the caps or are they required to prevent an air leak?
 
Sincere thanks, in advance!

Well, I got it to run well enough to get the job done.  Here is what I believe the issue is:
 
I replaced the OEM carb with a cheap junky chinese carb that was under $15 on Amazon.  On the bottom of the float bowl on the OEM, there is a mixture screw - the "Main mixture screw" according to Tecumseh documentation.  On the replacement carb, there is no adjustment there.  I tried the OEM float bowl with the main mixture screw, but the main mixture screw "assembly" will not screw into the new carb far enough to hold the float bowl in place.
 
LESSON LEARNED.
 
I believe I'll order a rebuild kit and go through the OEM carb properly and put back on.  I can keep the chinese crap for an emergency spare.
 
Once again, the bitterness of low quality remains long after the sweetness of low price is forgotten.

Thank you for your reply, @AVB.  So I ordered the wrong carb, it would seem.  As I said above, I am ordering the rebuild kit for the one I pulled off.  I'll keep this non-adjustable one as an emergency spare.
 
I'll also take a moment here to plug Parts Tree.  I have no affiliation with them.  I'm restoring a Snapper LW357B Push mower for my girlfriend's son who just bought his first house, and I have added items to an existing order THREE TIMES, including just now with the Tecumseh carb kit.  The allow me to do so happily, in fact, they even suggested it!  So everything is being shipped under a single one-time $7.95 shipping fee.
 
They were the lowest price vendor for some items, but not for others.  I'll pay a little more to give them my business since their customer service is being so helpful.
 
I have seen other parts sources mentioned, and I may check them out.  I'm just a homeowner/hobbyist, so I'll only be buying small quantities of parts.
 
Anyway, getting back on topic, when I pulled the float bowl on the new non-adjustable carb, the bowl gasket "sprang" out.  It seems that it is too large for the bowl.  I used the old one from the original carb to get me running.  This Chinese carb does not appear to be what I would consider high quality.  I will not pull the caps.  I'll just pull the float bowl and blow air through the passages before I store it.  Perhaps I will spray everything down with WD-40 to prevent corrosion, and seal it in a zip-lock bag until I need it again.

I just installed it in late November, 2018.  I'm guessing that it's inferior rubber.  Nitrile would not have that problem.
It will be out until I need the carb again some day in the distant future.  Hopefully the carb kit will arrive before we get snow again.

Very interesting.  Well, I'll have a spare!