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2009 250SX, suspension help?

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Hi, I just got a 250SX.

I went to a 450 last year and although it was fast and easy to ride I was not thrilled, so now I am back on a smoker. I had run 125s before...so this is my first 250 and my first KTM (other than an old 1980 420MX I bought cheap, rode once, it back fired and kicked back when I started it, broke my foot and got traded).

The suspension has been revalved and resprung for a 230# rider, I am 165# so this will need to be changed. I have the stock springs for it.

If I just swap the stock springs back in, will the changed valving make it all messed up? I don't know anything about how valving is changed and what happens, I just know that it is either good or really bad.

Does anyone know how easy it is to put the valveing back to stock? Where can I find a manual that shows how the WP forks and shock are disassembled and re assembled?

I know I should just send it in to have it re-valved for me and have the stock springs put in...but I would like to see if I like the bike (I really wanted a 150SX) before sinking another $600 into it.

Another issue I am having is starting it is not easy. The jetting seems good (I don't want to go leaner) ,compression is strong, with a fresh plug it fires up first kick. But then when I go to start it again I kick a bunch and nothing happens, I pull plug and its soaking wet. Clean it, kick it, nothing. Pull it clean it, kick it, nothing. Put in new plug and it fires right up...then after I shut it off I get to repeat that whole thing.

I have started it 3 times and have gone through $30 in plugs to do it.

All my other 2strokes started first kick, were jetted perfect, easy as pie, never had an issue.

Where should I start?

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As far as starting, you need to pull the carb and see what brass is in there. Do a search and get some jetting data. It should consistently start with 1-2 kicks. Its easy and relatively quick.

As for suspension, at 165 its gonna be a stiff ride until you revalve/respring it. In the long run it will be cheaper to have a local competent tuner do the work, instead of doing it yourself and having to pay someone to un-f#ck your mistakes.

I say competent, because my local shop failed to properly assemble my forks after a service. I'm paying someone else to do it right.....

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As far as starting, you need to pull the carb and see what brass is in there. Do a search and get some jetting data. It should consistently start with 1-2 kicks. Its easy and relatively quick.

As for suspension, at 165 its gonna be a stiff ride until you revalve/respring it. In the long run it will be cheaper to have a local competent tuner do the work, instead of doing it yourself and having to pay someone to un-f#ck your mistakes.

I say competent, because my local shop failed to properly assemble my forks after a service. I'm paying someone else to do it right.....

I checked the jetting and it is what it should be (158 main and a 40 pilot)...maybe float height is the issue? I am sure its something silly i am overlooking.

Oh, its way way way to stiff for me, 7.2 rear and .48 forks.

I have the stock 6.9 and .44, What I was wondering is if I just put them back in and worked at the softer side of the clickers i would be able to dial it in.

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where is your air screw set at? start at 1 1/2 turns out from full in and turn it out 1/2 turn at a time and find a crisp setting, but don't go too lean. If you go more than 2 1/2 - 3 turns out, I would go 1 size smaller on the pj.

as far as the springs go, I would try the springs 1st, and see how it goes.

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where is your air screw set at? start at 1 1/2 turns out from full in and turn it out 1/2 turn at a time and find a crisp setting, but don't go too lean. If you go more than 2 1/2 - 3 turns out, I would go 1 size smaller on the pj.

as far as the springs go, I would try the springs 1st, and see how it goes.

Its at 1 1/2 now, very crisp and snappy, idles down smooth and picks up perfect.

Jetting seems good even though its very cold in NY, I can't really run it and gun it now with snow out (well i could, but i don't want to). I just want it to start with one quick stab of the kicker without having to swap a new plug in.

The plug comes out soaking wet when i try to start it up...hot or cold.

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sounds like your getting fuel and if you have compression all you need is spark. what plugs are you putting in it, cheap ones or ngk. have seen cheap ones have similar problems. i would also check spark maybe make sure its a strong spark possible weak coil but doubt it just a couple more ideas. whats the color of plug when you pull it out? good luck

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float height is likely your issue, at least it is what you should look at first. Check it, and set it slightly lower than factory settings. You could also have debris in the float check valve not allowing it to seal as it should. Anywhere close to proper jetting and it should kick over and not flood.

springs aren't that hard to swap. I would start with swapping out the rear spring and ride it, making note of the clicker settings. Valving may or may not need to be changed. FWIW, I wouldn't try to revalve yourself either the shock or the TC forks. Both require knowledge and proper tools.

Fork spring replacement isn't bad, but you have to drain the outer oil. You can lower the fork oil to 330 cc's to see how it works. Beyond that, need to know what the bike is doing to suggest clicker adjustments. Helps if you know how to tune out the bad traits of susp with clickers.

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i am going to bet that you have a leaking crank seal... if you drain your oil and dont have 800 cc of oil then thats probably your problem. its a fairly easy fix..

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i am going to bet that you have a leaking crank seal... if you drain your oil and dont have 800 cc of oil then thats probably your problem. its a fairly easy fix..

How easy? Easier that splitting the cases and replacing it?

I have an owners manual...where is the best place to get a repair manual? I do not mind paying for a PDF download.

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float height is likely your issue, at least it is what you should look at first. Check it, and set it slightly lower than factory settings. You could also have debris in the float check valve not allowing it to seal as it should. Anywhere close to proper jetting and it should kick over and not flood.

springs aren't that hard to swap. I would start with swapping out the rear spring and ride it, making note of the clicker settings. Valving may or may not need to be changed. FWIW, I wouldn't try to revalve yourself either the shock or the TC forks. Both require knowledge and proper tools.

Fork spring replacement isn't bad, but you have to drain the outer oil. You can lower the fork oil to 330 cc's to see how it works. Beyond that, need to know what the bike is doing to suggest clicker adjustments. Helps if you know how to tune out the bad traits of susp with clickers.

I can tune suspension pretty good IF...big IF it is pretty close to start with. I need a baseline to start from then I can tweak it. I am afraid that it may be way off and I will correct he wrong thing and create a clusterF.

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I can tune suspension pretty good IF...big IF it is pretty close to start with. I need a baseline to start from then I can tweak it. I am afraid that it may be way off and I will correct he wrong thing and create a clusterF.

As long as you have a knowledge of how to assemble/disassemble the susp, then it shouldn't be too hard. But, like you say, not knowing the why behind the setup may have you going in the wrong direction.

I would spring it first and ride. Mine was valved light for a lighter rider and it worked pretty good till I could get it done for me.

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How easy? Easier that splitting the cases and replacing it?

I have an owners manual...where is the best place to get a repair manual? I do not mind paying for a PDF download.

you dont have to split cases...remove right side clutch cover, clutch/hub,

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