I think I've got the idea from reading past posts, but I want to be sure.

I have an 05 Raptor and I have bought a Carbon Fiber RS3 Yoshi full system and a proflow K&N. I plan to take the lid of off the box and use Dynojet for jetting. I live and play at sealevel and our average temp is about 60*.

What would you suggest for a starting point with jetting?

 

Here are the specs i run on my 02 LE Raptor........

02 Black LE 660R Raptor-Big Gun Full System-Stg.1 Hot Cam-L&A air box eliminator-K&N Fltr-170/175 DJ mains-25 pilot-air/fuel-2.5/2.75 turns.

I have an AIR BOX eliminator on my carbs, So it does breath a little easier.......

 

I would go with 150/155 with 25 pilots 2/2.25 turns out. That would get you pretty close. The dynojet kit only comes with jets upto 150, so your gonna have to buy the 155 from dynojet. Id buy 155-170 just to make sure.

 

I suggest you set your fuel screws at 2 3/4L and 3 R using stock pilots. Put your DJ needles on the 3rd clip. Now buy a bunch of DJs from Dynojet..........sizes 155, 160, 165, 170, 175...........
Start out using 170/175 and work your way down. Keep going down till you hit that flat spot in the upper Rs, then go back up one and your set. Just for reference, I had the same intake but with a full HMF and my sweetspot jetting was the above using 165/170DJs. Your jetting may vary with your pipe.
I know its not scientic but mine ran circles around all other piped Raptors I've raced..........and I really miss it!

 

148/150 with needles on the 4th groove from the top. Stock pilots 2.75 out. You do not need jets above 150, I ran 146/148 with a very similar setup at sea level.

 

I wouldnt be saying he WONT need them for sure. I jetted velocyraptor's at 150/155 with :No lid, stock filter, wb e-series, at sea level, 3 turns out (dynojet suggests 3 turns out on both). I think dynojet suggests 146/148 for a full exhaust and a lid, so a 148/150 just wont cut it, taking off the lid makes a HUGE difference in air flow.

tripmoon, if I were you (and Ive been in your situation) I would buy 155-175 DJ style jets from dynojet and start messing with the carbs. velocyraptor (my brother) was running 150/155 with needle on the 4th groove down and it was right on. Your gonna need more jets if you plan on modding your engine any further, so buying bigger sizes now will make jetting easier in the future. Hope this helps!

 

caliraptor - Just because you installed bigger jets in someone's quad does not mean that the quad was properly jetted. Did you ever run it on a dyno with an A/F probe? What was the A/F ratio?

tripmoon - Try 148/150 and do a plug chop at WOT. If you've got any color at all on the spark plug porcelain, you could safely drop down to 146/148. If it gets 20 degrees colder though, you'll have to come back up from 146/148. Most folks jet until the plug has a nice light tan color. That's actually a little rich and they are giving up performance. The plug should burn itself clean except a small color ring down inside the body where the porcelain meets the metal, any tan or brown on the porcelain is unburned fuel.

 

His bike might be different than yours or mine or little johny's accros the street. I suggested him to get more jets JUST IN CASE, I tried the 148/150 combo on velocy's bike and the plug had NO color, its safer to be a bit richer than lean...even if you give up 1hp. Same thing happened to me, I took the lid off and the 148/150 didnt do it, had a flat spot in the revs. Even if the 148/150 works for him, its always good to have extra jets around for when you mod the bike a bit more. Jets are only $3ea so its not a big deal. Just trying to help the noob, I know I wouldve liked help when I wanted to jet my bike for the first time.

 

Thanks guys..... This gives me a good starting point. I'll let you know how it turns out!

 

What about DJ vs Mikuni? Any considerations there? - It seems like Mikuni is easier to come by......