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Discussion Starter #1 (Edited)
hi guys,

I know they say you need to look deep down in the porcelain, do WOT chops, ect. for a complete reading, but what about what you see now? What can you tell needs some work, and what looks good? I think im a little rich on low end. The transition from closed to under 1/2 throttle is not as smooth. Right after the transition it pulls strong.
This plug has no more than 10hrs on it
20201010_231411.jpg


98939
 

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I this for the 2000 250EXC?

What oil mix are you using? "Classic" ones tend to use 30:1. We run ours at 40:1 and plugs are black. Som of the later model ones are recommended to use up to 60:1... but if you do that you better make sure that everything is in top condition in the motor!! If this is for the 2000 250EXC I would use 40:1. But others might differ

Your plug is much more oily than ours. When was motor rebuilt? Or at least given a new piston and rings?

If your only problem was the issue below 1/2 throttle I would fit the circlip on the needle jet one step lower, but I think you have other issues based on the plug...
 

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hi guys,

I know they say you need to look deep down in the porcelain, do WOT chops, ect. for a complete reading, but what about what you see now? What can you tell needs some work, and what looks good? I think im a little rich on low end. The transition from closed to under 1/2 throttle is not as smooth. Right after the transition it pulls strong.
This plug has no more than 10hrs on it View attachment 98939

View attachment 98939
I dont get overly scientific with plug readings if the motor runs good and plug has color to it. Dont want any white porcelain but tan is fine. If she runs good on that plug she's good to go. Be sure your engine warm up procedure isn't fooling your plug color. Blipping and revving engine to warm it will turn shell black when your tune is fine. Warm up motor at steady 4-5000 rpm and dont allow it to idle. Dont want revs too high when warming but dont let it idle. Okay to clear it out when warming but dont scream it either. LLP
12315.jpeg
 

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Discussion Starter #4 (Edited)
Hi guys, the last rebuild i sent out the cylinder to get replated and a new vertex piston and ring. The x and z dimensions were set to spec. This piston was put in at hour 46.3 on meter. I noticed the meter stopped work around 140hr. Add 30 more hours or so, totalling about 130hrs on new rebuild. Still has great compression. Some folks with kickstart bikes tried starting it one time in the trails when I submerged in water and after 5 kicks they where done, this was after they saw me kicking it over 30+ times. Toolkits for the win!

Yup, this is a 2000 KTM250EXC.


Ive been using Motul 710, 93 octane at a 44:1

I suspect the warm up part may be causing the wetness. I do let it idle and blip the throttle slightly to keep it from dying after unchoking. I then ride slow circles around the yard until i hear a crisper throttle. As i go around, i crack the throttle more everytime to listen for the crisper sound. If i dont do this, it will studder in the beginning.

Yes the clip, i did move up to the top position #5 on the CEK needle when summer hit. It fouled a plug on me on two occasions while starting it for the day. Toolkit for the win!
Q What was a 1 kick wonder everday before summer, became a fouling plug. Noticed it trending so i moved the clip from position #4 to #5. Made it much better. Now it's a 2 kick wonder.

I currently run:
Pilot 38
Main 172
Needle CEK position #5 (top most)
1.25 turns out on air screw but have been playing with it the last ride.

Elevation is between 50' - 300' in Connecticut

After the engine is completely warmed up, it sits a a very nice idle.
 

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I wonder if your rich running is attributable to wear on needle jet holder or high float level and not jetting. Your jetting numbers look correct and your idle seems okay so it seems your above idle is your complaint. Or your wet sloppy plug could be the problem and caused by improper warmup procedure? Are you sure plug is correct heat range? I'm not sure I would condemn a bike for requiring 2 kicks to start, but if it starts on 2 and runs sharp and crisp it's probably not tuning problem. I would try to correct your tuning first and see if that corrects your 2 kick starting requirement. It may take some experimentation to get your tune perfect, but your fuel and premix ratio are fine. No changes needed. Maybe give carburetor a look. Loosely threaded jet or worn needle or worn jet holder can make them blubber with correct jet numbers. Also consider replacing jets with factory jets as some foolish tuners can drill your correctly numbered jet and some of the cheap gypsy knock off jets can sometimes have quality control or calibration issues. Best to verify everything.
 

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Looks fine to me, just a bit oily. Does it blow much spooge?
If it's nice and crisp when warm and no flat spots or run ons, I would leave it be.
I had an rm250 that use to fowl a plug every now and then on warm up, but I reckon as the dog mentioned it was all in warm up technique. I actually find it best to let it start, give it 20 seconds to sort out it's choked revs then get on and get going, but don't rev the sh-t out of it.
I would be happy if my husky started 2nd kick.
I only ride mine once a month and usually takes 3 or 4 to start.
 

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hi guys,

I know they say you need to look deep down in the porcelain, do WOT chops, ect. for a complete reading, but what about what you see now? What can you tell needs some work, and what looks good? I think im a little rich on low end. The transition from closed to under 1/2 throttle is not as smooth. Right after the transition it pulls strong.
This plug has no more than 10hrs on it View attachment 98939

View attachment 98939
Serviced my bike today and pulled spark plug for a look. I was curious how she was burning after a healthy run recently. Looks a lot like yours without the carbon on shell. Running 50-1 Motorex
20201017_122304.jpg
 
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