Just wondering it anyone else has noticed a knock/rap kind of a noise? Mine makes the noise when I give it gas from idle, trying to figure out what it is or if that's just how they sound? I know my Kodiak was kind of noisy that way. I'm burning premium so it shouldn't be pinging, my plug still looks pretty new, but it is starting to get a little tan so it shouldn't be running lean, could it be the valves? i'll probably take it in and have the valves adjusted around 10-15 hours, it only has like 6 hours on it right now and about 100 miles. Maybe i'm just paranoid???

 

I get the same noise cold .I think it to the forged piston.A forged piston needs more piston to cylinder wall clearance because it is more dense and expands at a greater rate than cast.

 

Both comments are correct.I noticed that when the atv was new it took at least 10-15 hours before it loosened up and ran smooth(i had pre-detination).I've also notice piston slap on my Kodiak when it's cold.