On a Royal mod.RFT-50 deep fryer,the pilot light lights but when I turn the temp knob to light the main burners i don't get the gas needed for lite up and the pilot goes almost out.

SOURCE: Pilot Light

i had this trouble with a different fryer. We had lpg instead of natural gas. check youre using the correct gas.

SOURCE: Imperial deep fryer IFS40 pilot lights, turn on

Hi there, it sounds like your thermopile, for the pilot, is failing during use, when this happens, the small DC voltage it generates is less than the gas valve requires to stay open, and shuts off the pilot, which shuts off the main burners. Another thing that could be happening, is the hi limit is opening prematurely, instead of shutting of the pilot at 450 deg. it now is opening at 325, or 225 or 250. Sometimes the sensing bulb gets broken where it pass's through the oil tank causing this symptom. If you temporarily bypassed the hi limit to test this also, and it still goes off, you need a thermopile. If it stays on, check your temp with a reliable thermometer, and see if it reads fairly close to your setting, if so, then you need a hi limit.
Hope that helps, and thank you.

SOURCE: comercial deep fryer pilot light goes out

This problem could be caused by a few different things. You should check the condition of your pilot and the thermocouple, if the pilot is weak due to being dirty you will not generate the optimum Millivolts to run the fryer, you may need to dissassemble and clean the pilot. The thermocouple needs to be correctly placed in the pilot assembly, if it has dropped down to where it is not in the flame it will not work correctly. You may need a new thermopile as it may not be generating millivolts as needed. Gas pressure can cause this as well, if the pilot goes out then the main burners come on you should check the gas pressure. One more thing to check is the hi-limit thermostat, if this is cutting out early your pilot will go out. Imperial uses a self-resetting limit, after a few minutes your fryer will relight and work until if cuts out again. If your fryer pilot stay on with the thermostat off for long periods of time and does not go out immediately when the burners come on and the pilot is clean, you may need a hi limit. This is a lot of info, I hope it helps.

SOURCE: Pilot going out when thermostat turned on

It could also be the high limit thermostat shutting the pilot lite off.

SOURCE: Light pilot on Royal deep fryer. Pilot will not

there is a small adjustment screw on the gas valve,turn it clockwise to increase pilot,if that does not work the vent cap on the gas regulator on the back of the unit could be stopped up,remove that cap ,clean out or replace unit can operate without it just fine.If you increase the pilot and it still wont stay lit replace the thermocouple