Check your decomp lever specs if its off it will start when bumped or pulled but will not release enough pressure when trying to start with the starter, if you have a compression gauge i see that is the way most guys set up the decomp lever, i believe they say between 65 to 75 cranking psi.
2006 TRX450ER
HOUSER SLICAST L/T +2.5
FOX FLOAT EVOL
FOX PODIUM REAR W/GTT LINK
LSR AXCALIBAR +2
LSR STEM +2
LSR SPROCKET GUARD
LSR SKID PLATE
HRC KIT
K&N DYNO TUNED
K&N FILTER & POWER LID
HRC HEADER/HMF CARBON FIBER RACE CORE
QUADTECH HOOD
JETTRIM STEP SEAT
HIPER REARS 9x9 DBL
HIPER FRONTS 10x5 SBL
ITP QUADCROSS 20/6/10
ITP MXR4 19/10/9
PRO ARMOR FAT PEG NERFS
BLINGSTAR DC RACER BUMPER
FASST BARS
POWERMADD
PRO ARMOR SKID PLATE
QUADFORCE GRAPHICS