Re: Throttle cable
Yes, it's the end in the carburetor. Cut off what you want gone as cleanly as possible... a dremel with a cutoff wheels is perfect for the job. Clean up that business end of the cable and use silver solder with flux for silver solder. I find it helps to first wrap a strand or two of copper wire around it as the solder then grabs better. Then use the dremel with a grinding wheel or diamond tip to shape it to the same dimensions as the old stop you removed. I realize you may know all this, but someone else is reading your post who did not know how and now they do. There is a nice video that Norm did on shortening a cable.
Someday when I grow up I will probably lose interest in toys with wheels, but until then...