Pklove

I’m beginning to get the impression that this is the Yugo of kilns.  
I now have drill bits for 40, 5/64, 50, and 60…I’m getting seriously good at that.  No two sources have said the same thing.
It doesn’t help that the manual is so horribly done and that Olympic is …well…not in the running for when I upgrade.
I would prefer if they just said “that model is obsolete, you need a new burner system” instead of wasting my time.

(Olympic recommends 5/64ths.) In Michigan these bits are common at any hardware store.
I have been a round a few of these and even converted one to a =downdraft salt kiln (short life). Start slow with gas and as Bill said small adjustments on the flue are critical .6 burners should fire this easy to cone 10.
Digital pyro is also key to use.

#40 orifices are larger than # 50 and # 60. With #40’s and a blue flame you max out at about 37000 btu per burner, which would be about 225000 btu for all six. That’s a lot of energy for a small kiln.
So stalling can be because of atmosphere but is often because of damper adjustment. Especially this kiln. Really small adjustments are needed to maximize the energy in the kiln and just keep it out of reduction. When I say really sensitive, I mean 1/32” or less to trap as much heat as practical while just staying out of reduction.
 I would also double check sizing and pressure - #50 orifices net about 34000 btu per burner, #60, 11,000 btu pr burner so a huge disparity there so likely some misunderstanding.

Thanks for the response.  
 
The top shelf is over an inch below the top.  Dampers are set to keep the atmosphere neutral, no reduction stink. The stack is loose, no plate shelves and open in the middle.  A good two inches from the walls, plenty of room to breathe. Gas is not full bore, about 75% and the flame is blue at the burner tips . 
It climbs great to about 1700 F (500 degrees an hour) and then it struggles and craps out at 1800.
I’ll check out the link, I’m guessing that you are thinking “convert it to a downdraft.”  Which is what I’m thinking.  Which I’ll probably do anyways.  I just want to fire, I’ve got a ridiculous amount of work made already.  Soon I will not be able to get into the studio without causing an avalanche.
The thing is rated to cone 10, and I’m only shooting for 6.  So I figured that it would be easy peasey.  Ha.
Time to start digging in the archive.
(That is hilarious, most of the replies are from you.  You must be shaking your head thinking “another one.”)

Thanks for this Bill,  I’ve been beating my brains out juggling the specs from Olympic (which are only for the later model of this kiln, not what the OP posted pictures of...and mine is older) and the random stuff online.  This helps soooo much.