2021 YZ250 spark plug reading

Train_driver87
Edited Date/Time 5/2/2021 9:09am
Hello, just got a new 2021 yz250, and since its really cold here in Sweden I jetted my bike for colder weather. 0 alt and around 3-5C°

#185 main, #52 pilot, Suzuki needle (NEDW)(3) and a/f screw -1/4 turn

Basicly I took the numbers from the Yamaha yz250 2006 service manual.

Now I just need some help reading my spark plug, I fked up with the choke so I ran like half a lap with it on dunno if that caused the oil in the threads?

All help appreciated, kind regards


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DynoDan22
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DynoDan22 5/1/2021 5:32pm
5/1/2021 5:32pm
Oil in the threads is normal. Riding with the choke on and not noticing it for a half lap is not normal. Lol. Plug looks fine. Run it.
Mr. Robinson 5/1/2021 6:00pm
5/1/2021 6:00pm Edited Date/Time 6/2/2021 8:55am


This is a great diagram for plug reading. But, remember, plug readings really need to be done with a "plug chop".


Train_driver87 5/1/2021 11:34pm
5/1/2021 11:34pm
DynoDan22 wrote:
Oil in the threads is normal. Riding with the choke on and not noticing it for a half lap is not normal. Lol. Plug looks fine...
Oil in the threads is normal. Riding with the choke on and not noticing it for a half lap is not normal. Lol. Plug looks fine. Run it.
Nervous from not riding for 2 years and previous bike was a newer yz450f 🙈 First I thought my jetting was off, but yea I know what you mean... 😅
Train_driver87 5/1/2021 11:50pm
5/1/2021 11:50pm
Mr. Robinson wrote:
[img]https://p.vitalmx.com/photos/forums/2021/05/01/490637/s1200_plug_reading.jpg[/img] This is a great diagram for plug reading. But, remember, plug readings really need to be done with a "plug chop". [img]https://p.vitalmx.com/photos/forums/2021/05/01/490638/s1200_17848N3EW340.jpg[/img]


This is a great diagram for plug reading. But, remember, plug readings really need to be done with a "plug chop".


Thanks great picture, I’m getting some new plugs so gonna try do a chop 👍🏻😊

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DynoDan22
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DynoDan22 5/2/2021 9:09am
5/2/2021 9:09am
Someone needs to make a video showing what the different carb circuits do and what lean/rich sound like. I always jet by listening to the motor throughout the entire throttle range. It takes a lot of experimenting and trial and error but when you get it right, the sound and throttle response is amazing. The misleading part about a plug chop analysis is that it technically only shows you a reading at wide open throttle. I could throw in a proper main jet with a lean needle and still seize the motor.
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27thmx
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27thmx 6/2/2021 8:47am
6/2/2021 8:47am
Plug looks ok maybe a little lean. I look for light tan in our bikes

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