dconley989 said:
so assuming everything is stock, if i put the 410s in it should i definetly change my neddle setting to 3 or try just changing the jets and seeing how it runs. and should i do anything else after installing the 410s.
Gut the airbox, seriously it helps with these fusion 600's, also makes it a breeze to get the airbox back in and seated correctly and is completely reversible. I went through with small screwdrivers and lifted each tab holding the airbox halves together until they started the separate then stuck a piece of wood between the halves and did this all the way around until it popped apart. Then remove the funnels/foam from the inside and that funnel on the top of the airbox, now run a bead of rtv black silicone around the whole airbox and stick her back together and let it dry. Seals it up great and is still reversible if you decide to put the funnels/foam back in at a later date. Some people also recommend a strip of duct tape around the whole thing also to ensure a good seal and no under hood heat is making its way in.
Now here is the important part of this "operation". By design the fusions pull air in through the headlight adjuster knob, around the windshield and around the headlight. This is all fine and dandy until you get into powder or you are running behind other sleds on the trail as a ton of snow dust will get sucked in and you don't want that going into your engine or freezing up your carbs. Open the hood and remove the 4 rubber straps holding the windshield/black border in place then remove the black border around the headlight from the outside of the hood. You will see a couple of open slots that are direct shots into your intake and into your carbs if not sealed properly once the airbox is gutted since it no longer has the foam or funnels to keep the snow out. Get some clear silicone caulk/adhesive and carefully run a bead around the whole headlight sealing it up nice and clean since it will then be covered by the headlight border when you put it back on. Black duct tape works great for the other various holes and the headlight adjuster knob.
Now finally the needle setting, once my airbox was gutted from the SLP air horn, I had a slight bog off the line when I punched it. Some told me lean, some told me rich. I finally found a thread on hardcoresledder talking about this and how the fusions have a lean mid range stock, so I simply bumped the clip to #3(middle) which raised the needle and bam my bog was gone.
Any other questions just ask!
PS, if you don't gut your airbox, i'm sure the stock needle position(#2) should be fine unless you experience any bogging issues in the low/mid range.