Gas Stove/fireplace problem

[Davej]

Had to install a gas shutoff valve on the back of a direct-vent gas fireplace (free-standing ornamental stove) to meet code but now the main burner seems to be acting strange. Sometimes it goes out or doesn't want to light. The pilot stays lit. I am wondering if some dirt or rust might have been knocked loose and is now clogging the internal workings. I tried to clean out the pipe with a Q-tip as I was installing the valve but maybe there was still a bit of dirt left inside. I'm not sure how I might be able to blow any such dirt out with compressed air? Ideas?

Thanks

[Davej]

It occurred to me that the problem might be insufficient flow due to the added valve itself. I installed a 3/8" ball valve because the pipe on the back of the stove was 3/8" iron but what if the restriction of the valve causes insufficient flow? I guess I might be able to install a larger valve with with reducers. I will also check to see if running the furnace has any effect. This stove is on a separate line that branches off only a few feet from the gas meter.