Cecilware fme40 propane model .flame is soft. what

Most NatGas devices will convert to use of LP by changing the orifice.

GRINDMASTER CECILWARE F177A ORIFICE 52 1 16 LP GAS

Propane is delivered at a higher pressure it is also a hotter burning fuel then natural gas. One thing you would need is a pressure regulator that would reduce the gas to city pressure which is about 1/4 psi. If you can reduce the gas to that pressure you may not need to change the orifice but you may still need to adjust the air mixture to get a blue flame. A yellow flame would indicate that it is not burning correctly and is emitting unsafe levels of not properly burned gas. That looks like a Rannai I would check with them. It also looks like a ventless, Make sure you install it more then 3 feet from an opening (windows, doors, soft vents, other vents in the house) and not under a window.
Best of Luck
Ray

On the top of pressure regulater is a removalable piece that fits one way for nautral gas and the other way for propane i am wondering it was installed upside down afer ya reassambled it, accidenttly setting it to propane which defeintly will cause that

try to contact the manufacturer. i don't think you can get second hand conversion kit.

Sounds like you need a gas regulator in the main line.

Either that or you are using a natural gas fryer on propane which is a no-no if not converted properly.

You will need a manometer to determine your gas pressure, the amount required is posted on your appliance. Take both a static and dynamic reading on the inlet side of the gas valve. If it is not high enough consult a plumber. If it is take a reading on the manifold side. If the gas pressure is too low again consult a plumber. If it is within spec check orifaces and burner tubes if any for debris and spiders.

you will need a propane conversion kit designed for that particular model heater.
which would most likely consist of a heavier spring for the gas valve and orifices for the burners depending on how many burners you have.
Most all gas heaters come thru the factory set up for natural gas and most have a kit available for conversion to LP (Propane) You will also need a manometer or a gas pressure tester to check the incoming and outgoing pressures from the green (2ndary )regulator outside your house to the gas valve inlet side,usually 11 to 14" WC( water column) pressure( static) 14" being MAX!!
Outlet pressure with burners running 10-11" WC approx. This info should come with the conversion kit if available. If you are not comfortable working with gas then find someone who is, for safety reasons.

Goto 3wire.com.Search the site with the s/n.To do the conversion you need to change the pilot,burner orfices,gas valve and pressure regulator depending on the model but usually their all the same.Any questions let me know.

if the gas pressure is good on inlet and outlet of valve u might wanna chk the burner trays and manifold for flakes, dirt, spider webs ect... once u kno the passages are clear from obstruction you can focus on the mechanical. (sounds like gas valve may be getting weak and not able to open fully)