loanstar

no never had it out and checked it, in the right direction. Ran perfect 2nd kick start always, before I changed the exahust and jetted with the JD kit. The air fuel screw oring was torn when I pulled it out so I replaced it. In reading a bunch of thread I could have a piece of oring in the circuit or smething.Im going to clean out the pilot circuit with air and contact cleaner. Would you recomend anything else. I will repost once I clean it out.

I have a yz400 that I recently put on a FMF Q2 spark arrestor and powerbomb header. I also installed a JD jet kit. blue needle 4clip,170main, and 45 pilot. I was able to get it running right away but when I took it to the local mx park I was having a hard time starting it. It will only start with the choke open and hotstart open. Once started if I turn off the hotstart it just drops a few ideals if I turn off the choke it just dies. Before I put the jet kit in and exhaust I had a 180 main with stock needle 4clip down pilot jet is #45. I had the air/fuel screw about 1 1/2 out from bottom. I am a newbe with jetting and doing alot of trial and error. So far just getting fustrated. I couldnt hear and differences with adjusting the screw because it would only run with the choke open. What direction should I be looking. Pilot Jet?? elevation 1000 ft. 65-80deg

I have a 99 and the fuse near the battery the wire cracked inside the wire casing. The bike sometimes wouldnt start then it would. It was wierd but replaced the fuse wire and harness for $5 at an auto store and everything is fine. One of the mechanics at a local stores said KTM only has one fuse for everyting he recremended using 3 fuse one for the engine, battery, and lights so you never get stranded from a fuse problem. It would require rewiring the bike. hope it helps

Those are both good ideals. I tried starting it again the last night it stated without a problem like normal. It was hotter then normal that day I had trouble. I think it was something to do with the air mixture screw from talking with friends. Im not a mechanic when it comes to Carbs. I will get a new plug and have a friend help me clean out the carb it cant hurt.

I have a 99 YZ400F. I had it for about a year and before that it was in storage for 3 years. It always started on the first or second kick. I never had a problem starting it like others have had till last night. The bike started up on the first kick like usually after ideling for about a min I put the choke back in and the bike shut off. I was unable to start it for about 45 min. I tried everyting hot start, choke on, choke off, pushing it, etc. I had no tools with me. Has a clean air filter, and good gas. I turned off the gas line and kicked it like mad and it finally started. I dont think I flooded it? While started I turned back on the gas. It was fine for the rest of the day. First time having this problem, I will try it again tonight but does anyone have any thoughts or ideals on what to further look into.