My 08 TXC250 jetting is acting a little strange ... Maybe someone here can shed some light .. I put in a JD carb kit over a month ago and thought I had the bike dialed in pretty good as outlined below ... the plug at this time looked OK...and maybe even a little dark ..... but still tan looking ... The bike would not start yesterday so I replaced the plug (CR8EB) with a new one and it started ....old plug had about 2500 miles ... I took the new plug out after just a little riding and it was snow white! This was after some 1/2 - 3/4 throttle riding ... Why would the bike suddenly show the plug as very lean after the plug change? I've dropped the clip back down on the needle jet to the 6th notch and it has changed the plug color slightly but not enough ... It appears the main jet is too small to me but still confusing on the differences in the 2 plugs .... ... Do any of the asian bikes use the same Keihin CARBS as the Huskies? Maybe I can pick up a main jet from one of the dealers here ... I should add the bikes feels and sounds fine running ... Old plug is on the left n all the pics ... Original settings: 185 main red tip needle clipped on notch 3 from top (new setting: moved clip to slot 6) fuel screw at 1.5 turns out 42 pilot jet 65 bleed jet
I think:the old plug was crap so it looks dark (not burning)- the new one can burn more gas so it looks clean-lean. Don't Jet by plug color- too many variables to be accurate. Its been said that new gas is misleading- though it is a vague guidline if you have a problem- if the plug is wet/dark versus dry/ white. Plus you'd have to eliminate the cause down to being a specific circuit- and hope the ap doesn't through off your readings... If you are testing on the bench that effects it too- since it runs different under load. If your idle circuit is lean with a fat starter jet you may think the pilot is good so you enrichen you main only to still be lean and also have a rich condition- what would your spark plug say?: whatever the last throttle position was at when the bike was shut off. so it would continue to look lean>> purpose is for example. Id focus on: How's it start cold/ hot? How's it Idle and rev at low, mid and high rpms on the trail? if you wack or chop the throttle dose it hesitate, stumble or bog, or die? Sounds like you must be pretty close to perfect as you didn't list any running problems. Every Major Manufacturer has used the Keihin FCR Carb: so those jets are common. Jets are cheap so you can test till you feel comfortable. I didn't work with the JD red needle I used Keihin needles (EMP, EMN) and so the 185 seems big to me but thats because of the lean red needle. All I can say is try a larger one if you feel it would help or make you more comfortable.
Thanks for the info .... The bike runs very well like it is now ... Starts first kick usually cold ..1-3 kicks when hot .. idling is no problem ... No bogs ... I've just never saw a plug that color but then I have always ridden 2Ts till this bike ...This is actually the first plug I have ever changed n it ... I'll watch it a few more days and see how it acts ... and I have new IRC VE33 knobby to try out Sat and Sun
My bike stated bogging in the lower throttle ranges so I an moving the clip back up on the needle ... This is a little confusing to me but nothing new there ... A lean setting will cause pinging?
The color is getting better and I'm back with the needle clip at #3 from the top ... color is looking and I get to test ride again tomorrow All the snow at first was apparently just BS as outlined above by HuskynX ....
