NEW 2014 SX 250 fouling plug problem!

I just bought a brand new 2014 SX 250 2 stroke, My Ktm dealer adjusted the jets for my climate and sea level but it still fouls the plug when I start it from cold, each time I have to take the plug out, swop it for a hotter plug (7) start and clear out the the engine then swop back to the cold plug (8). Then it runs ok when engine has warmed up, can't leave the hot plug in because it burns white (too hot). I've done 15hrs total, I'm running 50:1 Motorex 2T oil, Dealer recommends 60:1 but everyone at the track said that's too lean!

I'd rather be running at 40:1 but she loves fouling plugs and I'm afraid it'll get worse at that ratio??

Any help with carb specs and float levels would be appreciated.

Thanks,

Jono

Perth, Australia.

30deg Celsius (av. Temp)

100m above sea level

Edited by jodirtaye

um 50:1 is more lean than 60:1 More oil is less fuel that is lean not rich I run 32:1 in our KTMs

Edited by gruberyz

um 50:1 is more lean than 60:1 More oil is less fuel that is lean not rich I run 32:1 in our KTMs

Sorry I meant a bit lean on the oil side, I'd rather mix with more oil but the owners manual recommends 60:1

What jets are in the bike?

What jets are in the bike?

carb settings;

pilot jet; 40

main jet; stock 158

needle; N1EH (POSITION 3)

I moved the float level down a bit (bent the tab down slightly from 2.44mm to 2.17mm) so the fuel level is lower in the bowl.

Ok this was what I wondered ....same as 11-13 SX..

N1eh is pooh through it away!!!

Try 42. Nedh. Or nozh. And 172 main.

carb settings;

pilot jet; 40

main jet; stock 158

needle; N1EH (POSITION 3)

I moved the float level down a bit (bent the tab down slightly from 2.44mm to 2.17mm) so the fuel level is lower in the bowl.

 

Is this exactly what the book says to use at that temp and elevation?

Sorry I meant a bit lean on the oil side, I'd rather mix with more oil but the owners manual recommends 60:1

Yeah sell more gaskets and cranks that way. 

Run 40:1.  Use the table in the manual to get a basic setting for your altitude and temperature.  Make sure you have a clean and properly oiled air filter and fresh premix.  Buy some BR8ES plugs (very cheap if you foul plugs) and make some minor adjustments to the settings in the table. Boxes in the table for higher elevations and warmer temps will give leaner settings.  Often a change as small a a clip position on the needle, or change in the air screw will get things into the acceptable range.  After you get it sorted you can switch back to the regular plug, but many just continue to run the ES plugs.

 

I guess the other thing to ask is if this bike is a major step up for you in power?  If so, you may need to run the jetting a little leaner until you get used to the bike.  I had a 20+ year lay off on dirt bikes, and it took me a while to get back up to speed.  I had to run things lean for a while until I got my speed back.

Edited by rpt50

I run 52:1 and have never had any trouble at all. I run it in all my bikes. Everything from a KX65 to my 250s. They all love it, even my chain saws love it. I have never seized a motor or had a bottom end go out. If you experience any of those problems it is the brand of oil you are using or your jetting, not the ratio. If you use crappy oil you need more of it to do the job.

Does your bike spooge? Is there black soot in the end of your silencer? Sounds like you are way to fat. Jet leaner and try riding it. The #1 cause of spooge is to fat on your jetting.

What gas are you using. If you run race gas the jetting chart will be way to fat. It is intended for pump gas.

Thanks for your replys.

I'm running 98 octane so will try leaning the needle setting also adjust the airscrew accordingly.

I see on KTMtalk.com they recommend changing to an RM08 needle because all the stock KTM2014 needles are crap.

What also conserns me is the slight knocking nois, like it's too far advanced. I'll see if the new needle setting fixs this

Thanks

Thanks for your replys.

I'm running 98 octane so will try leaning the needle setting also adjust the airscrew accordingly.

I see on KTMtalk.com they recommend changing to an RM08 needle because all the stock KTM2014 needles are crap.

What also conserns me is the slight knocking nois, like it's too far advanced. I'll see if the new needle setting fixs this

Thanks

RM NECJ....

KTMShane699 has posted a reply in the forum topic KTM SX 250 2014 carb specs:

My 2014 250 SX has a carb off of a 125 on it (38mm instead of 36mm). I put the Suzuki NECJ needle on the third clip, the 6.5 slide off the 250 carb, a 175 main and I think a 40 pilot. It's also got the FMF factory fatty and shorty silencer on it, red power valve spring and the adjuster set flush with the cases. Shane

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