I recently put a pro circuit t4 on my predator and I am not quite sure what I should be rejetting to, I have a k &N filter on and it has had a port and polish. Some help would be great.

 

I used a jet kit from Dynojet on my 07 pred....it comes complete with many sizes of jets, a new needle, etc. and good instructions. From there you just gotta run it and tweak it to get it right. $50 or so for the kit. There are other kits out there, too. You definitely want to rejet though, or you won't get the power out of it you should be. BTW, did you redo the intake (air box)? Makes a hell of a difference on the preddy!

 

I was going to say call Pro Circuit because they should of given you a "Base Recommendation" but I see you also have had a porting & polish job done, call up the shop who did the job tell them what you have for a set up and if they know a screwdriver from a socket they should be able to give you a BASE setting---Emphasis on BASE, because each motor and P&P job will have some variance from job to job---If it was a home version P&P then call Pro Circuit-ANYWAY- once you have a base setting then you'll have to grab a few NEW plugs and make a few runs and check your plug condition to judge if you need to go richer or leaner---Remember even though you get more power running lean(which also will burn up pistons) your better off running a tad rich to make up for when you run it in colder conditions. Don't let it scare you, its not a hard job just a bit of time spent changing jets and plugs, have fun doing it. Here is a link for you to show how to judge your plug, it explains and shows you step by step and it applies to all motors 2&4 stroke,Auto....ect..---http://www.totallyamaha.com/sn...tion%20%20Overview.htm