RE: 3w-75ius vs 3w-75 qs
Scott, the pic makes it look close, but there is about 3 inches seperation. The muffler stacks angle back. The tube is flush under the motor box. Scroll up to the first pic without the cowl and you will see what I mean.
That tube is the carb snorkel anyway. It runs into the fuse to regulate the air on the air side of the carb. There would be no consequence if it burned through.
Jess