I have been working sporadically on my PW205 which definitely needed a renewal of the NRV and a new fuel cap gasket. I had to fabricate the pip using Viton material and the first few times I put it together and pumped it up, the pump handle slowly emerged indicating a leak. I reassembled it several times cleaning surfaces and stretching the internal spring a bit and ultimately it held warranting a fuel fill and lighting. The stove lit easily with just a bit of flooding on initial light(probably my inexperience) , but the flame settled down quickly and purred along. However when I opened the valve to get a higher flame and to support the second burner, the flame tended to go to half yellow/half blue. I allowed it to burn for 15 minutes or so and the yellow was reduced on the main burner and only slightly present on the secondary burner. Adjusting the light up valve (second one) did not seem to affect the situation. Does anyone have a suggestion of what the issue is for the yellow flame tendency when the valve is opened to half or full throttle. I'm going to guess that there may be a bit of gunk in the generator. I'm a bit confused by the grid of holes in the center of the main burner. I assumed that it was a way to put more heat on the generator for faster startup, but only when the stove was nearly shut down did I see flames coming from those holes as opposed to those on the perimeter of the burner. My plan at present is to fill it and let it run for awhile to see if any improvement will result from fuel running through the system.