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Old 12-23-2012, 10:36 AM   #1
prichmon OP
Gnarly Adventurer
Joined: Feb 2009
Location: Huntington, wv
Oddometer: 138
KLX250SF Carb starting and cold run issues

I have done significant research but can't get the bike to start and run right cold.

From a cold sit:
pull choke
turn on gas
hit starter for 5-6 seconds - no running
wait 30-60 sec
hit the starter for 3-5 sec - may run or may not
wait 30-60 sec
hit the starter for <3 sec - usually runs
Idles for 1-2 minutes as it heats up then dies
crack throttle and crank -- bike restarts but must hold throttle open with choke off to make it run
After 3-5 minutes it will maintain a low idle without throttle.

Once warmed bike runs GREAT.

I have owned a dozen+ motorcycles and have NEVER had this much trouble making them run right. Cold or HOT!

I have rejetted to a 124 dynojet main, KLX300 adjustable needle on the 3rd position, changed the idle to a 38 with 1.5 turns out. Lastly I drilled the choke orifice to ~19-21 thousands. No Toil Air filter, air box top off or on has had little to no effect on running. Exhaust has been drilled with a 1/2" through the baffle and end is drilled with 6 1/4" holes in the end cap.

The only thing I can come up with is a lack of "1/2 choke" which allows mild enrichment. The sf has a carb which the choke is on or off only.

If anyone can lend a hand I would appreciate it.

prichmon is offline   Reply With Quote