gutted my box

[98670X]

Hey all, I gutted my airbox today on my 670 summitx now from what i read in the search , jet up a couple of sizes. But when i checked my needle , it was on the highest setting, so i dropped that to 3 , now that will richin my mixture for 1/2 to full?. im at 290/300 mains, should i go 310/320? the machine sounded boggy comming down the hill yesterday, when i went for a good climb seemed to power out/not bog at the top of the climb, should have checked my plugs but didnt till i got back down to the cabin clutch side was greyish brown and mag side was darker brown/black. anythoughts, going out around noon tomarrow im gunna do a fullout and pull the plug stop in the medow, but its a good 15k of riding to get there
Thanks

 

[maierch]

clutch side was greyish brown and mag side was darker brown/black.

I would be weary of a WFO check if you are already greyish brown on the PTO. Take it in little steps. It may save you a hole in the top of your piston. Richen things up on the PTO Side by raising your needle (Lower the clip).
The needle jets effect the amount of fuel delivered from about 1/4 throttle (just off the pilot jet) to about 3/4 throttle after that the fuel delivery is metered by the main jet. Hope this helps.

 

[DRD]

I hope you didn't throw the air box internals to far away. There wasn't much left on the table with regards to air intake on a stock X motor.

 

[magnet]

i totalyy gutted mine last year. cut the center right out of it. didn't notice any difference at all. plugs stayed the same and didn't pull any harder i didn't think anyways.

 

[99summitx]

Wow that's lean jetting, stock on 99x is 340/350 I gutted mine and run SLP twins and running 360/370 with EGT around 1150 degrees at 8100rpm

 

[98670X]

hey thanks for the replys. Went up the hill but before i went i changed my jets to the stock 340/350. really warm day +6 on the hill at 7000ft. sled seemed to do better lots of fog so i couldnt do the full climb to were i bogged out last time. didnt notice much of anything with the gutted box ,just added parinoia of my intake suckin some powder down to the carbs when 'dockin around.
What altitude you running at 99summitx?
Oh and when i checked the jets yester day they had them backwards, 290pto and 300 on the mag side. Still have a bog when comming down the trail at 1/4 to half. i droped the jet needle from the very top to the middle.....thinkin about one more notch down ,#2

 

[98670X]

wondering, could my bog been a rave valve issue? never taking them apart.

 

[Modman]

wondering, could my bog been a rave valve issue? never taking them apart.

doubtful, they just work on pressure and shouldn't cause a bog on the motor, probably fuel related IMO. Pilot jet maybe needs to be bigger or maybe bigger emulsion tubes. Raising or lowering the needle will only get you so far, if the tube is limiting the fuel flow, then moving the c-clip on the needle won't make much difference.