Why can I not advertise a motorcycle cover?

Hope someone can help

When I try to advertise (in Motorbike > Motorbikes, Accessories & Parts > Accessories > Motorcycle Covers) using AMS Amazon advertising (PPC sponsored products). All the motorcycle related products come up as “ineligible” at the “Choose products to advertise” stage. It says"Products in this condition are not eligible for advertising in this product category"

Is there some sort of gating taking place for advertising in this category?

Thanks

Not all types of product can have sponsored ads. By the sound of it thats one not on the list.