The precharger/ Prefilter is a good idea if you ride in alot of mud and water, as it helps repel the water. But like the others said, you do not need to rejet just because you added the filter. About the only time you need to rejet is because you you have added an aftermarket exhaust.
Honda Foreman Forums: Discuss the latest Honda Foreman in our free Honda Foreman forums. Also talk about Honda's other ATV and UTV's including the Honda Rubicon, Honda Rincon, Honda Rancher and Honda Recon