Honda ATV Forum banner

modded 426ex

3243 Views 22 Replies 5 Participants Last post by  SlammedRanger
hello first time posting on the site. i have a 03 400ex and going to bore it to a 426 i have a stage 2 hotcam big gun rev box white brothers e-series slip on exhaust im having gt thunder hd head studs installed and a 88mm wiseco 11:1 piston and have the head mating surface trued up and a port and polish atm with a 10:1 piston stock bore i have 168/42 jets in the carb with choke removed and an opend air box with a k&n airfilter with a precharger need a little help on starting position with the jets ive read alot of forums and think a 180 185 and 190 should be what i try any advice?
1 - 1 of 23 Posts
Do not bore your stock sleeve to 88mm. You can purchase an 88mm sleeve from LA or Wiseco. Make sure you upgrade the timing chain to a 2002-2008 CRF450R/450X- 2006-2008TRX450R/450ER chain part # 14401-MEB-671. Replace the guides too.
1 - 1 of 23 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.