Yamaha kodiak engine noise

Question

I have a 2004 yamaha kodiak 400 4x4 that at low speeds is fine but when you pin it the engine knocks a bit. My friend has a wolverine which seems to do around the same thing. Is this normal for a yamaha. The engine runs perfectly, does not smoke or die and no lights come on for over heating or anything. If not normal what could it be?

Answer 1

hi ivegot an 07 400 grizzly with same noise as well