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2009 Big bear 400 motor build

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Old 07-18-2018, 01:47 PM
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Default 2009 Big bear 400 motor build



Figured I would post up a build that I'm currently doing for anyone else interested in making a little more ummff out of the BB.
As of right now, I have a epi comp clutch kit, k&n, hmf pipe, and warrior snorkel. The bike is on itp SS wheels and 29.5 outlaws. I tuned it with a sigma 6 jet kit using a aem wideband welded in the pipe. Current jets are 116 main and I believe a 22 pilot (not 100% sure have to double check) with about 1/8-3/16 shims under the needle. Has a lil bit bigger hole drilled in the slide and about 2 rings cut off the spring. AFR is 13.5@idle and light throttle at low rpms and richens up to 13.0 at light throttle high rpm and 12.2-12.4 @ WOT. (I'm at sea level in Houston) Thing fires up instantly cold or hot with no choke and rips for having 29.5's and throws em around in the thickest of mud no problem.
I'm still wanting more out of the lil BB because I'm tired of watching my buddies that all have grizzlys and Kodiaks 660's and 700's ripping wheelies all the time through ****. Lol even tho most of the time I'm the one winching them out of mud holes. The BB is just a tank of a wheeler.
Here's the plan and stuff I have ordered. (Stock bore) Wiseco 11:1 piston for a warrior Webcam #1617 grind cam (almost the same as 388 grind) Spring kit with titanium retainers Suzuki Ltz400 mikuni 36mm carb with raptor 350 manifold Sigma 6 stage 1-7 jet kit Head will also be ported as much as possible while it's off (I build and tune alot of racecars around here and I have ascess to a superflow flow bench for testing)
Only thing I'm not sure of right now and can't get any info on is a cdi box for these bikes that has a hotter spark curve?
The goal is to keep the reliability and improve the low end grunt and still add quite a bit of mid-range and higher end power but mostly focus on the mid-range because the clutch kit definitely jumps into the rpms much better then stock. Parts should be pileing in over the week and weekend and should be ready to rock by next weekend. I'll keep you guys posted on the progress as I get cracking on it. If any of y'all have anything to add, I'm all ears and would be greatly appreciated.
 
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