I have a 04 Raptor 660 that i just bored to a 686 with a wisco high com. piston and a stage one hot cam. I have LTE pipes and it is jetted and has uni air filter with no air box lid. I was woundering if i need to change my jets bc it seems to be slower now that bored it and putt the cam in it. Thanks

 

Yes, you need to rejet.

 

Are you saying you still have the stock 140/145 jets in it? If so I can't beleive you haven't burnt a piston yet. I put an HMF muffler and a proflow intake with a unifilter on my 05 and am at 160/165 and it needs to go to 170/175 to run without the lid on the airbox so I'd say you need talk to the outfit you got your 727 kit from and see what they recommend for jetting befor you melt that sucker down.

 

He's got a 686. I have similiar mods but without an airbox and Im running 180/185 DYNO JETS @ sea level
Depending on your elevation I would suggest 165/170 or 170/175 DYNO JETS. I would buy all the jets from 160-200, you never know when you might need some bigger/smaller jets.

 

if your bike was getting rgiht prior to boring your motor, your going to need to increase your jet size, whatever percentage you bored to from a 660 to a 686, what the percentage that increase is, you need to use the same percentage to increase your jet size. either way you need to jet

 

I have 155/150 jetts in my raptor now. I talked to trinity raceing and thay said i need 170/165 so i orderd them. How do you get it where when ever you post something at the end it telles about your 4wheeler.

 

727, you must go to your profile page and type it in your signature box...............[img]i/expressions/face-icon-small-cool.gif[/img]

 

I have a very similar set up and i am using Mikuni mains 175-180 and my raptor runs very strong.If you are sea level to about 1500 feet the jetting i use will work for you.The fuel you are using could be slowing you down.What compression are you running and what fuel do you use?

 

Im running 11 to 1 comm. and high test gas.

 

I am not sure what you mean by high test gas but with 11:1 compression you should be fine with pump premium.If you did a topic search you could fing some past postings about octane levels needed for particular compressions but believe me you will only go slower with more octane than you need.