The intake is a 2 1/2 inch tube to the carb which is just barely larger than the carb's intake diameter
. It turns at a 30 degree angle and opens up to a 4" intake at a 30 degree angle. I tried to fit a 5" filter, but then I could not run an air box and you will want a box in wet, snowy conditions. The air box fits under the frame instead of between the rails for more space for the air cleaner to breathe.
The radiators are PWR Oversize.