I just tested the new LPG carburetor, which is a dual-fuel carburetor, and I couldn't get it to run properly. The motor sounded terrible with this gas carburetor. I tried more LPG and less LPG using the tuning screw, but it made no difference; it was still running poorly.
I put the original modified LPG carburetor back on, and it ran perfectly again. I'm not sure why the new carburetor was so bad—possibly the LPG connection in the new carburetor doesn't have an angled fitting inside to draw gas. One thing I thought I shouldn't have done with the homemade LPG carburetor was make the venturi so large, as I drilled the carburetor out as far as it would go.
You can see the differences in the venturi in the picture below. I guess I can use the new LPG carburetor as a petrol-only carburetor on another mower if I want to get some use out of it.
It has been a few years now since I started using an LPG mower, and I still haven't needed to buy any LPG, as I have been using up gas from discarded LPG bottles.
