by rheron » Mon Dec 27, 2010 2:11 pm
2007 CRF450R, stock motor, 42 idle jet, fuel screw ~ 2 turns, JD jetting main/needle, megabomb, stock exhaust.
Went down on the trails and bent the stock pipe pretty well, then decided to try the megabomb. Went riding but found that the bike felt very peaky (hitting very hard down low but not having the smooth mid that was there on the stock pipe), so changed jetting to the JD jet kit (at recommended 190, red needle and clip in fifth position).
Now the bike is starting very inconsistently (sometimes fires on the first kick (choke, no throttle) but most times, just kicks over like its flooded (can smell gas). Is this something to do with the megabomb (should I take the idle jet to 45 ?) Dont expect any issues from the JD kit but wonder if going to the megabomb if I need a different idle jet ?
Bought the bike ~3 months ago and had a shop measure the valves (intake at 0.008"). Only been on three rides since.
Sucks to have the bike misbehaving in the middle of the riding season. Already dropped the fuel, checked the idle jet. Next steps planned are:
1) pull, inspect and replace plug
2) carb teardown and clean
3) valve re-measurement and adjust
Any suggestions before I start digging in are appreciated.
Ralph-