Yes they are adjustable. To tell you more it would require a model number. But for the most part, they have a small double valve with a slotted top on the front deck manifold between the burner valves. Usually with a hole or slot that you can put in a 1/8 th or 3/16 ths inch blade screwdriver. Counter clockwise will be more and a little goes a long way. But make sure the pilots are clean first.
Yep, a model number. However, I did a SWAG to post this illustration. This is probably your stove’s setup:
In that setup, Tri-Star uses a tandem valve arrangement so one pilot adjuster valve supplies TWO pilot burners. The pilot adjuster is #11. As illustrated, there’s one pilot adjuster valve per each front/rear set of pilot burners. On your six burner stove, there will be three sets of pilots.
Note that #10 is a T-fitting which splits the gas feed to supply two pilot burners.
Adjusting a pilot adjuster valve asfixbear explained should raise or lower the front and rear pilots in unison. Be warned that, if you back out the pilot adjuster screw too far, it can fall out and gas will spew out. So…use care when trying to adjust them.
I’ll add that if your pilots were fine some time back, but are performing poorly now, the pilot burner(s) probably got doused by numerous boil overs of -whatever-… and food stuff is clogging the burner ports. Sometimes cleaning those ports will help, but it’s not uncommon for a pilot burner’s tube to get clogged down inside of it as well. I’ve never real successful at clearing that out and have always found it best just to simply replace the pilot burner.
On that note, if find that to be necessary and you’re having a problem with…say – just a front pilot…with the rear pilot in that set seemingly okay, I still recommend replacing BOTH of the pilot burners in that set. That way they’ll both perform equally fresh and new. Otherwise, if you just replace ONE fouled burner, then you might discover that the OTHER burner wasn’t so good after all because ITS flame is too low while your new one has a huge flame.
Here’s the pilot burner you’re probably needing. However, you should call PartsTOWN with a good model/serial number before ordering: