The A1 license allows me to ride any motorcycle up to 47.46hp in Israel. It is my understanding that in the US a distinction isn't made between motorcycles based on horsepower, and that any motorcycle license allows you to drive any motorcycle. Would I be allowed to drive a 80hp motorcycle in the US with this license?
I might put it this way: if your license in your home country is sufficient to obtain a motorcycle ("A") rating on your International Driving Permit (and you carry your valid license along with the IDP), you should have sufficient documentation of your skills to operate a full-sized street motorcycle in the United States. If your license is in English and clearly indicates a motorcycle endorsement, that may be good enough in itself.
The IDP standardizes the various vehicle operator permits and endorsements from treaty countries into thirteen categories.
Since 2011, the relevant vehicle categories would be
- A - Motorcycles
- A1 - Motorcycles with a cubic capacity not exceeding 125cm3 and a power not exceeding 11 kW (light motorcycles);
- B1 - Motor tricycles and quadricycles;
Since 47.46hp is about 35.4 kW— well above the 11 kW level— it seems you could ask whichever company issues your IDP for the A rating. This being the regular motorcycle skill category on the IDP, I would expect it to be treated as a regular motorcycle endorsement in the 50 U.S. states and in Washington, D.C., just as they recognize each other's motorcycle endorsements.
There is very considerable variation from state to state on what the cutoffs are at the lower end— there is no standard definition of a motorcycle in the United States. If you can only get an A1 rating, therefore, it is possible that you would not be allowed to operate anything large enough to take on the freeway/expressway, which would make a coast-to-coast trip extremely difficult.
I'm not aware of any such separate licensing categories for larger or higher-powered bikes anywhere in the U.S. For good or ill, once you get a motorcycle endorsement here, it's good for a 3 hp street scooter and a 205 hp 1299 Panigale alike, and up to you to operate only as much bike as you can handle. The cutoff between a motorized bicycle and a motorcycle/"motor scooter"/"motorized cycle" is low, often 1kW or 0.75kW, and often based on engine displacement and wheel diameter in addition to or instead of power.
Standard warning: as licensing and traffic law enforcement are handled by the states, it is good to review the laws of every state you plan to operate in.
The American Motorcyclist Association provides a handy online summaries of state motorcycle laws. Note, for example, lane splitting and filtering are illegal in most states, and only explicitly legal in California. As a daily rider myself, I would also caution that motorcycling is rarer in the U.S. than in much of the world; it is largely considered a recreational activity. Like bicyclists, scooter riders, and truck and farm equipment operators, you are thus at the mercy of car drivers who are not very accustomed to you, and who may resent your presence on the road altogether— and of police who see a disproportionate amount of reckless joyriding on two wheels.
Can I legally drive a motorcycle in California with a New Zealand motorcycle license? answers California and it is likely the answer similarly is yes in other states. (But usual disclaimers apply)