The pilot light won't stay lite

Question

i have a dyna-glo rmi-80lpt, when you light the pilot the flame goes on,ignates the gas,the flame comes on burns for a while and when it comes up to temperture the flame goes out and so does the pilot light. You have to relight the pilot everytime. Is there an online manual for this model or is it just out of date? Had it serviced but it still does it.Also we noticed the pilot light is at least 2 inches long and there's no adjustment.