For this type of issue you have to get the Mic out of the wind. Best way to do so is to place an external microphone you can place where is is shielded from the wind.
The video being shaky is always the issue when using a standard camera / camcorder. as they have a larger profile. Best for this type of application is a small profile camera. I use adrenaline systems helmet camera which has an extended microphone I place behind the tank..this give me very good engine sound. The small profile of the camera completely eliminates the shakes. check the system: Superbike Helmet Cam
The video being shaky is always the issue when using a standard camera / camcorder. as they have a larger profile. Best for this type of application is a small profile camera. I use adrenaline systems helmet camera which has an extended microphone I place behind the tank..this give me very good engine sound. The small profile of the camera completely eliminates the shakes. check the system: Superbike Helmet Cam