Boom vac hose size?

[lighthousecarwash]

I recently installed new pay per use JE Adams vacs mounted on poles with the swivel booms. JE Adams told me that the hoses had to be 1-1/2. Not sure if that is because of weight or the connection to the boom, but I am having constant issues with the hoses plugging up. My normal vacs at other locations are 2" hose and I never have any issues. For everyone running the swivel booms, are you also using the smaller hose?

Thanks,
Lighthouse