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2017 250SX suddenly dies??

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So I have 3hrs on my new 2017 KTM250SX. Got the bike jetted for my altitude ( Got a JD Jetting kit) and start the ride the bike is running perfect. Get about 20 miles out and the bike suddenly starts acting up and then shuts off. Thank goodness I was out with my buddy. But I checked the fuel flow that was good. Pulled the plug and it has no spark??? WTF this is a brand new bike!!!!! I did not have a spare plug with me so my buddy had to ride in and get my truck and come pick me up..... I guess I just got a bad plug for some reason. I ordered two new ones today but they wont show up till Wednesday... No bike shop in town has the plug I need. I guess some plugs just go bad early.  ANY ideas??????

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With every KTM I've owned I have always turned the choke off as soon as the bike fired,but if it was up to temp it makes this kinda moot. The issue of none of the shops in your area not having the plug kinda sux especially if one of them is where the bike was bought from. A BR8ES can substituted for the BR8ECM. Lots of shops stock  few if  any parts these days and offer to order it for you, I can order essentially anything they can and have it at my door sometimes the next day. Oreillys auto parts stores sell NGK plugs in this area so that's where I go for the BR8ECM plugs at ~ $8 a pop. 

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If you have no spark the wire near the rotor may have been shorted. Some have been rubbing on the rotor on the XC and XCW. Not sure if the SX has this issue.

Edited by yamafreek_hawaii

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Yeah unfortunately Jugnuts, my shop that I bought the bike  at didnt sell the fn plug? I ordered a few from Rocky Mountain ATV/MC and ill have them tomorrow.! Shops just dont stock shit anymore. I miss the old days of good dirt bike shops (70-80's)

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Are you riding in the powerband?

All the two strokes I've owned if you don't ride them in the powerband and keep revs low it fouls plugs non stop. You can run lower oil ratio in petrol to stop plug fouls but then if you do start riding top end you risk it seizing

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16 hours ago, Quincy Oconnor said:

Are you riding in the powerband?

All the two strokes I've owned if you don't ride them in the powerband and keep revs low it fouls plugs non stop. You can run lower oil ratio in petrol to stop plug fouls but then if you do start riding top end you risk it seizing


No and bummer your bikes were like that, either your jetting was off or you needed to replace your reeds or top end. 

You can putt around and never come on the "powerband" on a properly jetted two stroke all day long and never foul a plug.

Reducing the amount of the oil in the gas will actually make it richer, so again no. You pick your oil ratio and then jet accordingly, adjust for elevation and temp.



OP- did you try a different plug to try for spark? I'm guessing it's a the last 3 digits in the plug are "ecm" And the likely reason you couldnt find the correct plug. They are the same as the other ngk plugs just with a shorter porcelain, which is what the "ecm" stands for and you could use a standard length plug which you can find almost at any auto parts store. I have one in my 17. 

If you dont have spark with a new plug you may want to check under your flywheel for chaffed wires. 

good luck. 

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