Carb Question????

[iracekx]

I have a 2006 KX450 I just went through the carb with a fine tooth comb. I replaced the valve slide plate with a new one and the o-rings also in the carb. The problem is that you have to turn up the idle 2 1/4 turns to get the bike to start. Once you let it warm up then turn the idle back where it need to be the bike will fire up right after you kill it as of yesterday. I go out this morning it is 47 degrees and I have to turn the idle back up to get the bike started. In the past I had never had to do this before, here the past year I have just let the bike idle high. I am tired of that and wanted to get it working properly. If anybody has some suggestions they would be greatly appreciated. I am running the specs that team green ask to run on a stock bike. I have made sure that the boot from the carb to the head is in good condition and it is. It has me puzzled and I am trying to figure out what to do next.

[ktm300hater]

wheres the mixture screw at.. should be around 2-2.5 out. If its in too far and running lean it wont idle right

[Paw Paw]

Plugged center port in the pilot jet will do the same thing.

Paw Paw

[iracekx]

wheres the mixture screw at.. should be around 2-2.5 out. If its in too far and running lean it wont idle right

Team Green says that it should be at 1 and 3/4 turns out I will try the 2 - 2 1/2 and see what that does. Do you really think that would cause me to have to turn the idle screw up 2 1/4 turns to get it to start. After I went through the carb and turned the idle screw up and got it running I turned it down to around 1750 idle I would rev it the idle would drop back down. So I went out the other morning and to get the bike to start I counted it took me turning the idle screw up 2 1/4 turns before it would start. In the morning I will go out and turn the idle screw back down and turn the fuel screw out a little more and see what it does. Thank Hater

[iracekx]

Plugged center port in the pilot jet will do the same thing.

Paw Paw

I spent my time and went through that carb with a fine tooth comb and replaced alot of the rubber seals also and the throttle valve plate thinking that it might be worn. Thank you again for all your suggestions I really appreciate them thanks again to Hater he helped me get me bike going when my stator went out and no one could figure it out.

[iracekx]

I go out this morning it 65 outside and turn the idle back to where it was running with the bike warmed up at 1750RPM. I adjust the fuel screw to 2 turns out it would act like it wanted to start, but did not. I turned it to 2 1/4 and maybe a tad bit better then I went to 2 1/2 turns still no luck. I started to turn the idle back up this time it only took 1 1/4 turns of the idle to get it to start. Of course it is warmer than the previous day when I have to have the idle 2 1/4 out to get it to start. Hopefully this information will help troubleshoot the problem a little better I feel like we might getting a little closer.

[ktm300hater]

this is what I ran in our 08 175 main, 42-45 pilot (depending on temperature, this time of year a 45) NCYS needle on clip 3, air screw at 2-2.5 depending on temp (2.5 this time of year) and a 55 leak jet

It is possible that you put the slide together wrong and be able to look like its right. Also that oring in the slide is VERY critical. Double check it just to be sure.

I had a Honda 250f that had a small tear in that oring and it gave me fits

[p3ripperfw]

Have you ever checked the valves on the bike?

[iracekx]

Have you ever checked the valves on the bike?

Valves are within spec just have to have idle screw up high to start bike.

[iracekx]

this is what I ran in our 08 175 main, 42-45 pilot (depending on temperature, this time of year a 45) NCYS needle on clip 3, air screw at 2-2.5 depending on temp (2.5 this time of year) and a 55 leak jet

It is possible that you put the slide together wrong and be able to look like its right. Also that oring in the slide is VERY critical. Double check it just to be sure.

I had a Honda 250f that had a small tear in that oring and it gave me fits

I just went out to the shed to start my bike 64 outside idle turned up 1 1/4 from where it idles @ 1750 and the bikes starts on second kick.
I have a 175 main, 42 pilot, 72 starter jet, 55 leak jet I believe my needle is NCVR and the clip is in the middle position. The valve throttle plate was brand new and the seal was on it. I inspected it before I put it on and it looked perfect I also made sure I put the slide back together as the manual specs. I took my sweet time putting that back together to make sure I made no mistakes. It's just driving me crazy why I have to have the idle up high to it to start. Thanks again for everybody's help!!!!

[ktm300hater]

Ok, check this as its happened to me. Look at the pilot and make sure when you tightened it that a piece didnt chip off and partially block the hole. Also remove the pilot and mixture screw and get some carb spray with a straw and blow thru the pliot circuit from the filter side of the carb. When you blow spray thru the air jet you should get spray thru the pilot jet, the mixture screw and the adjoining hole in the carb venturi

try that, because you have to have a blockage in the pilot circuit of some kind

Or the hotstart is stuck open

[iracekx]

Ok, check this as its happened to me. Look at the pilot and make sure when you tightened it that a piece didnt chip off and partially block the hole. Also remove the pilot and mixture screw and get some carb spray with a straw and blow thru the pliot circuit from the filter side of the carb. When you blow spray thru the air jet you should get spray thru the pilot jet, the mixture screw and the adjoining hole in the carb venturi

try that, because you have to have a blockage in the pilot circuit of some kind

Or the hotstart is stuck open

I blew through all of those when I pull the hot start when the bike is running you can hear it rev up. Is it possible that the seal on the hot start is partially failing that is why it will rev up some. I blew cleaner and compressed air through every opening on that carb washed it out with soap and water and dried it out you could eat off of it. It seems a little better with the fuel screw turned out to 2 1/2 since I only have to have the idle up 1 1/4 turns. Let me know what you think on the hot start seal it looks OK, but you never know.

[iracekx]

Went out this morning 40 degrees outside would not start like it did yesterday on the second kick. I started turning up the idle screw 1/4 turn at a time it finally started when I reached the 2 1/2 turns. When I was trying to start it about the 3 or 4 kick it would pop out of the exhaust. This problem is driving me crazy it's probably the smallest thing that is wrong. Let me know Hater if you think that a partially failing o-ring in the hot start could do this. I looked on line and it does not look like you can buy just the o-ring and when I had it apart it looks like a special type o-ring it has a cut out behind it.

[ktm300hater]

The oring could be the culprit but if it speeds up when you pull it, I would think its working right. Im stumped, let me think on it some more

[Paw Paw]

If you did not pull the pilot jet out and use a welder tip cleaner in it you will never know if it's clogged or not. The center opening in that jet is very, very small and will plug with any dirt in the system. Pull it, clean it and then try to start it.
And yes a damaged hot start o-ring could cause the lean condition you speek of, but not in this case you have stated that it will speed up when activated.

Paw Paw