I have a 2001 raptor with a ct pipe, pro-flow filter,jet kit and I live @1000 feet.I had it jetted at 150 right and 145 left with air box lid and snorkel on as I do mostly trail riding and run creeks.It ran and pulled awesome. I drilled 10 1 inch holes in my box lid and installed uni vents. I then went up to 160 on the right and 155 on the left, to rich. I kept jetting back from here till I got to where I started. It dosen't make any sense to me, more air should mean more fuel. But anyways now it feels like it is asleep on the bottom end. As soon as the rpms pick up it wants to rip my arms off. Before I drilled the holes it ran and pulled awesome from top to bottom and now there is no bottom. I had checked yesterday with 4 different shops on air screw adj.[stock], and got four different answers, from 1 turn on the leftand .9 on the right all the way to 3.5 and 3. I would totally appreciate any help as I am sick and tired of taking the carbs off of this thing.

 

You should be fine with that jetting...What kind of jet kit do you have? Turn the air screw all the way in and then turn it out 2 1/2 to 3 turns out and see what that does. If you are running rich after that then jet it down. You should be getting plenty of fuel for that altitude.

Are you still running stock pilots???

 

Yes I am still running stock pilots. Last night I rode hard for about an hour and checked the plugs as soon as I shut it down. They were a nice brown color. I checked them again bout an hour later and they were a little darker.

 

The jet kit came with the pipe. Titanium needles which are bigger than stock. when I changed the jetting for the holes I had the clip on #4 setting. when I went back to my original jetting I left the needle on #4 which I found to be to rich on the top. I changed it to #3 and now its fine, except for the bottom. The difference of the bottom end before and after the holes is like night and day.Im dazed and confused.

 

If you've got a CT pipe and I assume CT's jet kit (the titanium needle part), then I would call CT and get some answers. Your setup is the one that "won" the rigged Raptor pipe shootout in DirtWheels. You should be able to give them your altitude and temperture and they should be able to get you really close, if not spot on. They do lots of dyno runs getting the pipe set up.

 

I have called ct and talked to few people down there,they had no info for jetting with holes in air box. They more or less told me to work it out myself. They gave me specs for no snorkel and/or lid.

 

NO HELP[img]i/expressions/face-icon-small-sad.gif[/img], Ok that's it[img]i/expressions/face-icon-small-mad.gif[/img],

HEY GUYS Spacollie sings show tunes at work.

 

i would try changing your pilots

 

those uni vents don't do shiot! go back to your original jetting!

 

Look at my posts and many others & you will discover that you can change, pilots, mains, needles, clip pos, etc till your blue in the face & you will still have a little problem down low when running w/out the lid or with most of the lid removed/cut open. Most people don't know they have the problem because it is not that prevalent when your riding but try opening the throttle slowly when in nuetral & you can truly feel/hear the problem area. I am currently working on modifying the throttle slides to restrict air flow at the lower throttle positions because you'll find that is the only parameter left that we haven't changed & it is the most influential part that affects 1/4-1/2 throttle. I would prefer to buy slides that have less cutaway & are richer but Mikuni doesn't seem to make them. If my experiments don't work I will do one of two things:

1) Leave my jetting as is- 22.5 pilots, 3 turns each, clip pos=5, mains = 165/170, all Mikuni parts, no Dynojet.
She absolutely rips from 1/2 to full throttle with this setup, better than any other jetting I've tried & trust me, I've tried em all.

2) Put part of my lid back on till the low end clears up-however, this will affect top end performance, its a sacrifice, personally I like having the top end rip!