HELP!

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. 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

40/1 is leaner than 60/1 Either ratio shouldnt cause the fouling though. Choke on, air filter? 

Here's my take. Bad ignition module.  The exact same thing happened on my 06 300. The cure was a new ignition module.  End of problem..  while it may not be your problem, I'd take it back to the dealer or talk to him about it

Edited by zilla

What is the jetting that is currently in it?

Ur jetting should be fine if it's set to specs. Something else is wrong here for sure.

cheers, will talk to my dealer again but he's not that helpfull. He reacons i'm not reving it hard enough when i first start it but i think its more than that.

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.

 

its not smoking excessively at all but going to check the gear oil when i change it to see if i've lost any through a leaky crank bearing...maybe?

 

thanks for your replies

40/1 is leaner than 60/1 Either ratio shouldnt cause the fouling though. Choke on, air filter? 

 

sorry, i meant a bit lean on the oil side. I just put a clean, new and evenly oiled filter in. choke on for the first start breifly then wack it off after 10 seconds before it chokes itself, then i start genetally reving it up till the radiator gets warm but it usually fouls a plug before i can get it warm 

Talk to your dealer, or go find a good mechanic if the dealership has no feedback for you.  Also check into this ignition module thing, I've never heard of it but sounds like Zilla might be onto something

I would demand the dealer to get it right you shouldn't have to do a dam thing it's brand new.

You have that backwards. 60:1 is more fuel per oil than 40:1 which means 40:1 is more rich than 60:1.

cheers, will talk to my dealer again but he's not that helpfull. He reacons i'm not reving it hard enough when i first start it but i think its more than that.

I can idle my 13 300xc for 5+ minutes on start up and not have to worry about fouling a plug, no need to rev on warm up. Your dealer guy is an idiot, definitely something wrong here. 

You have that backwards. 60:1 is more fuel per oil than 40:1 which means 40:1 is more rich than 60: 

 

 

fuel volume running through the carb jets. 60:1 is a richer fuel mixture than 40:1 60 parts gasoline to 1 part oil is richer in gasoline than 40 parts gasoline to 1 part oil. 

I ran my 13 150sx for the whole last season on the same plug, with a sparky, and without. Lugged it, rode it hard and never even had a blubber. Something more than jetting is causing this. If the dealer won't help you contact KTM directly. Good luck.

Be more specific on the air filter. Did it do it the first time you started it? Is it the same air filter as original? I say clean and oil it and start fresh. Maybe the dealer had some moron oil it and he over did it.

 

Whats the setting on the air screw?

The jetting sounds lean I'm at sea level I do have after market pipe but it's not that different from stock jetting.

45 pilot 170 main I can let it idle till it loads up and stalls,lug it in 3rd gear never fouls plug. Sounds like maybe bad coil or stated even could be as simple as loose connection on something.

I can idle my 13 300xc for 5+ minutes on start up and not have to worry about fouling a plug, no need to rev on warm up. Your dealer guy is an idiot, definitely something wrong here.

+1

I've cleaned the airscew intake hole (full of air filter oil and gunk) seems to have fixed the problem

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now