Heads up on 400i and 500i compatibility.

[JAKE JANACEK]

The 500i and 400i exhaust will interchange for the 03 models only. To retro fit the the 04 models to the 03 HMF slip-on you must use an 03 head pipe and some minor bracket modifications. Also, the Arctic Cat 500's really, really like to be jetted with the air box lid removed, but be careful if you ride in deep mud and water.

[KEVIN/HMF]

Jake, thanks for the heads up on the cat...IT'S VALUABLE INFORMATION.

[Kentucky Martian]

The 03 400i's Like the Airbox Lid off too :D