I have been searching through the posts off and on for the past week now and have still not been able to find an answer for my question/problem. I have a 2001 Raptor 660. It has a FMF Titanium4 slip-on (and mid-pipe), stock header, and I just put in the Pro Flow air filter kit. Right now it runs ok with the lid on. I haven't taken it out on any serious ride yet though. I want to take to lid off and run it that way, but I don't want to have to drop the $50-$80 on a jet kit. Can I just get some 150 and 155 mikuni jets and tune it to run well that way? If so, is that the right size jets? How many turns on the mixture screw? Needle position? I appreciate the help.

 

One thing to add....I am at 700ft elevation. (Tulsa, OK area)

 

Hey man, when I jetted my Raptor I ddn't use a kit. Its cheaper to just buy the jets singly. you will have to change the main jets on both carbs, and you will need new pilots too. I don't really know what would be the best for you, you can try putting in 150 and 155 but I don't know how its going to run. But you most definatly can do it, you will just need to get someone who has about the same set up as you do and copy their jets. Good luck.

 

that's probally a good start, and try 2 1/2 turns out on air screw

 

I run a CT header and silencer with Pro-flow intake K&N filter . I use 170/175 mikuni jets ( $6.00 ) jets elevation here is 2300 and low humidity . Thats on stock compression and it runs great ! Sounds fat but it's . air screw is 2.5 turns out and needle is on the 3 notch from the top .
Also NO lid
How that helps
Better to be a little rich and work it out from there . Than to be to lean and burn it down

 

Thanks to all for the info. I guess what my question is, is why to people buy these kits for much more that it would cost you to buy the jets? Because it it just easier? It seems that in the kits they always have to swap out the needle as well. Is that because they are not "Mikuni" jets in the kits and the needle with not seat in the "Mikuni" brand jets? I just want to make sure it is possible to acheive the same outcome as a "kit" without the higher $$ amount.

Thanks again for all the quick replies.

 

You can still use the stock needle with different jets. The only reason people buy the kits is because they say the needles have different lengths and tapers to them so they "claim" they add power. Some people are just lazy and want to buy all kinds of jets at once so they will always have larger/smaller ones for future mods.
In my opinion you are better off with buying single jets. .

 

wayyyyyy back when my dad drilled out my jets with a really little drill bit but i would not reccomend it if you are not good at wrenching lol

 

So I installed the 150/155 mains, and put it back together enough to start it and see how it ran. I let it warm up for 5-7 minutes. It started to backfire between 1/4 and 1/2 throttle (no load on engine, just in neutral in the garage). So I shut it down, checked the plug....way too lean...pulled the carbs back off and adjusted the mixture out to 2-1/2 and 3 turns. Started it back up and it wasn't as bad, but would still backfire around 1/2 throttle. This time I dropped the clip on the needle one position. This helped a little. I finally got it running good enough to put back together and test drive it. I will do that tonight. My question is this. My last adjustment was dropping the clip to the bottom position on the needles. Since I am maxed out on the needle adjustment, would I be better to just get the next size larger main and try that (and bring the clip back up to the middle position)? Next size up would be 155/160.

 

1/4 - 1/2 throttle will be your pilots that needs adjusting. There maybe some cross over from your needle, but at that throttle postition it "should" be your pilots that needs to be adjusted.