2017 KTM 250sx keeps fouling plugs

Tom_Symes
Edited Date/Time 10/27/2017 8:37pm
Hi All,
I'm new to 2 strokes and I need a little help.
My riding elevation varies between 0-500m sea level. My jetting is set at stock, which is also the same settings as where I live (3m sea level) besides turning out the air/fuel mix a quarter turn which I've done. Seems to fouling when I idle for 10-20 secs even when it's warm.

I've been through 3 plugs and I only put 4 hours on the bike...... PLEASE HELP!
ASO - 2
Pilot jet - 42.5
Stock needle- 43-73
Clip - 3
Main jet - 440
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Acidreamer
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Acidreamer 10/16/2017 1:15am
10/16/2017 1:15am
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running or theyre on the pipe. No in between.
Tom_Symes 10/16/2017 1:37am
10/16/2017 1:37am
Acidreamer wrote:
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running...
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running or theyre on the pipe. No in between.
I've been running 1:40 on 98 octane. I've mainly been trail riding at the moment. Only seems to be fouling when I'm on idle for more then 10 seconds.
sandman768
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sandman768 10/16/2017 4:09am
10/16/2017 4:09am
Go to next leaner pilot jet, maybe even 2nd leaner pilot... These bikes not really setup to be ideling around much, clean it out when warm by holding throttle open more often....if all your doing is trail riding the XC should have been your bike
CarlinoJoeVideo
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CarlinoJoeVideo 10/16/2017 7:34am
10/16/2017 7:34am
Acidreamer wrote:
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running...
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running or theyre on the pipe. No in between.
Tom_Symes wrote:
I've been running 1:40 on 98 octane. I've mainly been trail riding at the moment. Only seems to be fouling when I'm on idle for more...
I've been running 1:40 on 98 octane. I've mainly been trail riding at the moment. Only seems to be fouling when I'm on idle for more then 10 seconds.
Don't the new bikes call for a fuel ratio more like 1:60? My 125 is 1:60 on pump I believe.

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Paw Paw
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Paw Paw 10/16/2017 7:53am
10/16/2017 7:53am
Acidreamer wrote:
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running...
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running or theyre on the pipe. No in between.
Tom_Symes wrote:
I've been running 1:40 on 98 octane. I've mainly been trail riding at the moment. Only seems to be fouling when I'm on idle for more...
I've been running 1:40 on 98 octane. I've mainly been trail riding at the moment. Only seems to be fouling when I'm on idle for more then 10 seconds.
CarlinoJoeVideo wrote:
Don't the new bikes call for a fuel ratio more like 1:60? My 125 is 1:60 on pump I believe.
X2

Paw Paw
Goulding
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Goulding 10/16/2017 8:57am
10/16/2017 8:57am
I am up in Newfoundland. Riding elevation is at sea level riding temps between 10-30 Celsius all summer and am running stock jetting. I mix my gas at 60:1 with zero jetting issued at all. Haven't fouled a plug yet in my first 34 hours.
Jensenyo
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Jensenyo 10/16/2017 1:37pm
10/16/2017 1:37pm
What oil are you using? I wanted the best for my new 250sx and bought Motul 800, but found out that you really have to keep the bike on high rpms with that oil.. Spooged up like crazy when woods riding for example. Now im using motul 710 1:50 and the plug is dry and no spooge in silencer.
rollin64caddy 10/16/2017 4:57pm
10/16/2017 4:57pm
ktm it pretty adamant about saying that you should run the recommended 60:1 ratio. I ran mine at 36:1 for a bit until I switched to 60:1 and they are right.
rollin64caddy 10/16/2017 5:02pm
10/16/2017 5:02pm
Jensenyo wrote:
What oil are you using? I wanted the best for my new 250sx and bought Motul 800, but found out that you really have to keep...
What oil are you using? I wanted the best for my new 250sx and bought Motul 800, but found out that you really have to keep the bike on high rpms with that oil.. Spooged up like crazy when woods riding for example. Now im using motul 710 1:50 and the plug is dry and no spooge in silencer.
I run maxima k2. but what ever the manual recommends is probably good. I think its motorex isn't it?
Goulding
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Goulding 10/16/2017 5:13pm
10/16/2017 5:13pm
Jensenyo wrote:
What oil are you using? I wanted the best for my new 250sx and bought Motul 800, but found out that you really have to keep...
What oil are you using? I wanted the best for my new 250sx and bought Motul 800, but found out that you really have to keep the bike on high rpms with that oil.. Spooged up like crazy when woods riding for example. Now im using motul 710 1:50 and the plug is dry and no spooge in silencer.
I am using the motorex oil that Ktm recommends.
Tom_Symes 10/16/2017 7:42pm
10/16/2017 7:42pm Edited Date/Time 10/16/2017 7:44pm
Acidreamer wrote:
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running...
Youre still running rich or youre putting too much oil in your gas. Lugging the bike around can also foul plugs. 2 strokes are not running or theyre on the pipe. No in between.
Tom_Symes wrote:
I've been running 1:40 on 98 octane. I've mainly been trail riding at the moment. Only seems to be fouling when I'm on idle for more...
I've been running 1:40 on 98 octane. I've mainly been trail riding at the moment. Only seems to be fouling when I'm on idle for more then 10 seconds.
CarlinoJoeVideo wrote:
Don't the new bikes call for a fuel ratio more like 1:60? My 125 is 1:60 on pump I believe.
You boys are right. Just went through the manual and realized the 1:40 mix on 98 octane is only for the 125/150. it should be 1:60 on 95 octane......


Thanks everyone for the feedback.

edit: Im using Motorex 2T cross power

BobPA
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BobPA 10/16/2017 8:21pm
10/16/2017 8:21pm
If you are constantly fouling plugs it is not just an oil ratio issue, it is a jetting issue. 40:1 is fine, and more oil= more power for a two stroke....look it up.
swatdoc
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swatdoc 10/17/2017 5:51pm
10/17/2017 5:51pm
Didn't MXA have all kinds of issues with this bike when testing - then switch to 60:1 like they were supposed to be running, and all the problems went away???
Paw Paw
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Paw Paw 10/17/2017 8:37pm
10/17/2017 8:37pm
swatdoc wrote:
Didn't MXA have all kinds of issues with this bike when testing - then switch to 60:1 like they were supposed to be running, and all...
Didn't MXA have all kinds of issues with this bike when testing - then switch to 60:1 like they were supposed to be running, and all the problems went away???
Yes they did and that was after much testing.

Paw Paw
endurox
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endurox 10/27/2017 8:37pm
10/27/2017 8:37pm
float level is set to way to high. Needs to be adjusted about 3mm lower. The stock 17 reed block is junk. Suggest the moto tassenari 4R.

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