As is the case with most things in life the answer is: it depends. Certainly you won’t want to try attaching a gas motor to an inflatable kayak and there are numerous regular inflatables that shouldn’t be brought into contact with any type of motor, nevermind a gas motor. Some small to mid-size regular inflatables are built to accommodate battery powered trolling motors and provide you a secure pouch to store the battery. So if you see the battery pouch it’s a pretty good sign the boat isn’t gas engine compatible. Larger regular inflatables however are often able to accommodate full size outboard motors. And a gas motor won’t typically be a problem for a rigid-body inflatable.\r