So what do you guys think of the condition of the spark plug? Still learning about 2 strokes. So bear with me.

It was new when I got the machine. Other than running it here and there to get the machine ready for the trails not a lot of run time. Then the week of the 4th of July I put 120 miles on the machine riding the trails.

Running to lean? I'd say no. Running too rich or just right?

Getting ready to hit the trails again in about a week and if I need to make some adjustments I'm open to any thoughts.

Thanks for the feedback!

Later, SB4x4

Basically those pics mean nothing right now. They are almost worthless.
1) You need to tell us what kind of fuel you are running because pump gas and avgas color plugs differently.
2) You need to do a plug chop. That means you need to pull the white insulator out so that you can see the smoke ring at the very bottom of that tip which is located deep down inside.

The way I do it (which is rarely), is I use a hacksaw and cut the crimp at the top (located right where your sparkplug socket fits) and then just pull the ceramic insulator out.
CO

Gas is premium pump gas. Unleaded with no ethanol. 91/93 octane.
For Oil I’m running Yamaha 2R at a 32:1 ratio. Per my mechanic’s recommendation.

I’ll get another new plug and cut this one apart and will post a pic of that as soon as I can. I can take the plug into work and put it in the tool room lathe and use a cut off tool if you think that would work better. Would possibly give me a cleaner cut and I can control the depth of the cut a lot easier.

Thanks for responding!

SB4x4

Just use a hacksaw. Good enough. Cut to the porcelain or it won't come out. You won't damage the important part. Use the search box and type in "smoke ring". Then you'll know what to look at. Member adnoh is the guy to ask for real info on that.
I don't like pump gas. Every man for himself. Oil mix good.
CO

CO - there are a few other indicators without chopping the plug threads off. Heat range for one. Base jetting for another.

OP - chop off the plug threads please and re-post. We'll be able to tell a bit more.


1. The ground strap on that BR7ES may be just a slight tad too hot. Could be too hot a plug, or could be slightly lean. Consider running a BR8ES until you know for sure your jetting is accurate for the machine.
2. The threads look way too clean. Did you wipe the threads? if you did ignore #1...
3. A proper and rich tune will darken the last several threads. Yours are looking like new indicating LEAN or you cleaned off the threads.
4. The ring at the bottom of the plug has zero soot on it. This would indicate a lean condition. You want soot to circle around about 3/4 the base ring of the plug... Unless you wiped it down with a towel?

Yes I will admit, I am NO sparkplug expert.
Zero is one of our high performance guys here so you should give anything he says serious consideration.
If you don't, then you do so at your own risk.
There are several others on this site I consider pros but they're not posting anymore.
CO

Chopped the plug today at work. Did it in the tool room lathe. Nice and easy and clean!

Here are two pictures. First one is with the flash on and the second picture is without the camera flash on. The picture with out the flash to me is closer to how it looks to the eye.

Thanks for looking guys! Please give me your thoughts.

ZeroClient, Thanks for posting that picture as well as the comments/questions.

No I did not clean the threads off wire wheel them etc...Just how I pulled it out for the most part. There was I would say a little wetness to the bottom thread or so but nothing like a oily caked mess or a hard carbon deposit on it at all.

Thanks!

Expert or not I still appreciate you taking the time to look at it and respond. For one it's how we all learn as well. I know you have way more time with 2 strokes then I do. This is my first one. Besides chainsaws and leaf blowers! LOL!

Looks rich to me.
https://motorizedbicyclebuilder.com/how ... park-plug/
At the base it looks like more than 2mm and it is black. That says rich to me.
Sparkplug heat range looks ok to me based on those first pics you posted and looking at the tip.
Now we need zero to chime in.
CO

Its hard to tell. Plugs with a lot of miles on them don't read out very well. Indeed there is excess build-up from high throttle operation. It could be slightly rich fuel, or possibly a thick mix of oil greater than 40:1 ratio. In any case it looks safe to me if the Engine is able to clear out.

Is the plug really wet around the base and threads? If so, its very rich. Actually an extremely rich condition tends to show as lean on a photo. Extremely rich will not burn and just be overly wet when checked. In some cases the plug will come out white but very very wet indicating a very rich misfire is happening.

If its wet/rich, try raising the clip on the needle 1 or 2 positions to lean out 1/4~3/4 throttle.

If the plug is DRY, then it is LEAN. If its dry/lean I would try a carb needle that is 1~2 steps thinner. IE go from a EEC to an EED needle but only go one step. Maybe lower the clip position 1 or 2 spots to fatten the 1/4~3/4 section and see how it runs from 1/4 to 3/4 throttle. If it runs better between 1/4-3/4 but then doesn't clear out at full throttle then lower your main jet 5 points or so.

Make one jetting change at a time and write it down!

Rock on!

Thanks! The ground electrode (the curved hook on the very bottom of the plug) and like I said the bottom thread or so where wet when I pulled it out. Even the new plug that is in the machine right now. I pulled it out and it’s wet on the bottom.

Again I’m an old gear head car wise and understand cars and not two strokes but from the way I looked at the first time...that was my thought that it was running rich.

Driving it at low to mid speeds (low to mid throttle settings) it seemed like it was not loading up but just seemed like it was a little lazy at times but when you nailed the throttle the thing just hauled butt!

I’ll take your suggestion and adjust the clip on the needle. I’ll move it up one notch first and run it and see how it runs. Then if I have to I’ll move it up one more.

Yep I understand about taking notes on settings and changes and only doing one thing at a time. Did the same thing on the cars when we would do tuning with jets and the power valves etc...

When I get to it I’ll post back as to where the settings where to start with etc...and keep you guys up to date on it. Thing is we have stuff going on for the next week or so and I know I won’t get to it for a little bit so be patient.

Thanks again! SB4x4

I have a favorite story of my friend and jetting, he had his ATC 250R, I don't recall the size but not stock, we would take it over to the hill (olds at Glamis) make a few runs. he said it was running real good but thought it could go a little leaner and did a jet change, next run up he melted it down. moral of the story, if it seems to run good and doesn't foul plugs leave it alone, now if you are racing it's a different story but running a little rich will only cost you a little extra in gas and when it gets cool in the morning or evening you may notice it runs better. on the other hand, if it is running as good as it can such as you would want for race tuning then dropping into a low valley in the evening where it is cooler may be all it takes to do some damage. IMO, if you get it running as good as you can, then go back and richen it up a bit.