Reading Plugs

[BamaRat]

I have had my Zong for just under a week. I am having a blast with it. I am trying to learn as much as fast as I can about these bikes. I have heard(read) people talk about reading plugs. I tried to do some research on it but would like some of your advice in regards to reading the plugs on these bikes. I have just under 200 miles on mine and pulled the plug today to look at it. Please tell me what you think as I have no clue.





and here she is so Spud won't get mad because I didn't post a pic
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[TurboT]

Good looking bike!

Your plug looks alright to me, if not a little 'light', but that could be splitting hairs...and really the ambient light and flash of the camera can be subjective there.

What you don't want is for it to be white which means you're getting too much air and not enough fuel. (Lean) Running lean is worse for the motor than the alternative, which is 'rich'. If you're motor is running rich the plug would be black and carbon covered.

Right now it looks tan and that's what you're aiming for. Well done!

[BamaRat]

That is just the kind of advice I was looking for. Thanks Turbo

[waynev]

Yep, that looks pretty darn good. As for other info on reading plugs here's a good example of some plug conditions http://www.ngksparkplugs.com/tech_su...qs/faqread.asp

[MICRider]

Zong looks awesome! On a side note, is that your baja bug? I had one just like that but hemi orange with black fenders

[katoranger]

I was going to comment on the bug too. Looks like fun.

The plug looks good. Maybe alittle light. As you progress with the Spud mods :wink: , you will probably need to upjet the carb.

Allen

[Wild_Alaskan]

yep I also agree your plug is good. was this taken out after hard running or just idling? the plug only shows about the last 30 seconds of engine running most of the time

[SpudRider]

Thank you for posting the photo of your new Zong, Bama; she looks great!

Spud

[BamaRat]

Originally Posted by Wild_Alaskan

yep I also agree your plug is good. was this taken out after hard running or just idling? the plug only shows about the last 30 seconds of engine running most of the time

I pulled the plug after riding home from work today, so it was normal to light riding. Had not thought about it being the last 30 seconds but makes sense.


The bug is my other toy. I love it. It will go nearly anywhere it will fit.

[SpudRider]

I will admit, I am far from an expert regarding spark plug reading. However, I have heard you need to do a "plug chop" to get an accurate reading of your fuel/air mixture. Can anyone here elaborate on the value of a "plug chop?" :?:

http://www.thumpertalk.com/forum/thr...park-plug-chop
http://faq.f650.com/FAQs/SparkPlugFAQ.htm

Spud

[Wild_Alaskan]

By doing a plug chop you ensure that the plug is not changed after you have tested at the intended throttle.
For example when testing at full throttle, for the main jet size, you would run at full throttle for a minimum of 30 seconds then hit the kill switch and pull the clutch simultaneously so fuel is no longer entering or burning in the engine, which would skew the results.

[SpudRider]

Originally Posted by Wild_Alaskan

By doing a plug chop you ensure that the plug is not changed after you have tested at the intended throttle.
For example when testing at full throttle, for the main jet size, you would run at full throttle for a minimum of 30 seconds then hit the kill switch and pull the clutch simultaneously so fuel is no longer entering or burning in the engine, which would skew the results.

Yes. You then brake, and safely (hopefully) pull to the side of the road. Next, you wait for the bike to cool (see link below).

http://faq.f650.com/FAQs/SparkPlugFAQ.htm#Plug%20Chop

Finally, you remove the spark plug by the side of the road, and evaluate the color. Of course, you should begin with a brand new spark plug for each "plug chop." Have you done this, WA?

Spud

[Wild_Alaskan]

yep you pretty much got it , you can take the plug out while its still hot, as long as you can do it without burning yourself. i dont use a new plug every time, but if you wanted an absolute result it may be worthwhile. Ive done it a couple times on my old motor, came to the conclusion a 115 gives the best color at WOT, and that it ran very lean at 1/4 throttle, even with the needle fully up.

[suprf1y]

In my experience, that plug would indicate that you are rich, and quite a bit so. I don't think that plug reading is a reliable indicator of air fuel ratio with modern unleaded, alcohol enriched fuels. Not only that, these small bore single cylinder motors can exhibit some odd things at upper RPM's that would indicate a very lean situation, when in fact the very opposite is true.
Pull the plugs on your street car. Modern fuel management is quite good, but they do tend to run on the rich side for safety.
Look at how white they are.
My experience with race motors is that, by the time I got the plug looking a nice tan colour, I was 6-8 jet sizes too rich.

If your bike is running OK, leave it. If you're not happy with it, go up 2 jet sizes at a time, until preformance drops off, then go back to the previous one.
What would I do?
Leave it.

BTW, nice bike, and nice bug!

[fishman10]

thanks,that also helps me,my zong plug is lighter than bama,s so he has nothing to worry about.And I am a at a 132.5 main jet