does this spark plug look rich or lean?

[88redrocket]

im tryin to get the jetting dialed in on my new 310. Im running a 38mm tmx carb, 32:1 Super M.... i am running a 380 main jet which is the leanest size main esr recommends.
I took this pic of the plug after my first wot chop. it looks lean to me but i am no expert so i just wanted another opionion.

http://i42.tinypic.com/sfijjk.jpg

[Honda 250r 001]

you have to cut part of the threads away to do a accurate plug chop. thats why its called a plug "chop" Its hard to tell because you cant see down to the bottom.

[rustyATV]

Need some light on that end

[88redrocket]

ok here you go. (the electrode got bent while i was cutting it)

<a href="http://tinypic.com" target="_blank"><img src="http://i42.tinypic.com/10xh7pk.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

[05LSR250R]

Looks good to me! Is it running ok?

[gandgracing]

Wow, I must be running mine way to rich. That looks really lean to me, but I'm no expert either.

[88redrocket]

It runs pretty good except in the higher gears when i rev it up and upshift, it kind of "dogs" for a couple seconds before it starts revving. if i flick the clutch it comes right alive but id like to figure out why its doing it.

[05LSR250R]

Go up a size on the main and see what happens!

[88redrocket]

already tried that. I broke it in with a 460. then went to a 420, 400 and now the 380 and its done it with all of them. it seems like its getting more gas than it can burn which is why i keep trying to lean it out hoping that will solve it but i havent seen much difference. maybe i need to adjust the needle setting?

[cdrookie]

the needle is more for midrange than top end. i'd jet it up a size or 2 and also increase the pilot, that's too white for my liking. also check your float heigth, maybe too high.

[Honda 250r 001]

plug looks good!

[1promodfan]

I say its a little lean......not much though.

[woodsracer144]

for me thats way too lean... i like my plug totally golden brown... its better to be safe and spend money on a plug then to blow your wad on another 310...

[Honda 250r 001]

To be honest i have never done a plug chop so i would really know. but what i usually do is put main in know is to rich, and go leaner till it runs good. then i ride it for a day like that and look at the plug and it should give a more accurate reading. that has some white, some chocolate, and some brown in it so its sort of confusing.

[86 Quad R]

looks to be a weee bit on the lean side to me. as suggested, i'd go up one size on the main.

btw: what do you have the plug gapped at? usually it needs to be about .018 - .022"

[88redrocket]

I ended up going one size richer just to be on the safe side and it did improve the throttle response too so i think its all set. Plug is gapped at .20 thou. I will run it for a day and check it again. I think part of my problem was i had it geared a little high ( 14/37 with 18's). I put a 38 rear sprocket on it and the bigger jet and it pulls out of the corners alot better now.

[fulltiltrider]

That chop looked good to me. Your getting nice and hot when you got about a 1mm band that is that nice paper bag color. There is some power to be had when you get it close to danger, but if you like how it runs here its good and safe. Try jetting for alky sometime, gas gets easy lol.

[wilkin250r]

Originally posted by Honda 250r 001
To be honest i have never done a plug chop so i would really know. but what i usually do is put main in know is to rich, and go leaner till it runs good. then i ride it for a day like that and look at the plug and it should give a more accurate reading. that has some white, some chocolate, and some brown in it so its sort of confusing.

Problem is, that doesn't give you the whole story.

If all that ever mattered was the main jet size, they why have anything else? Why have a needle clip that raises up and down?The reason you have a pilot jet, a needle clip, and a main jet is because they all have different functions, they affect different areas.

It's certainly possible to be rich in one area, and lean in the other. You can be rich in the mid-throttle, but dangerously lean at wide-open. Different plug chops at different throttle spots will tell you the whole story and make sure you're running right everywhere.

[Lightninn]

Wilkin is on the money here. If you did the plug chop at WOT, then your plug reading is ONLY for that throttle setting.

If it's bogging from low to mid or mid to high rpm, then you need to address the jetting in that range.

I like to start at idle and work from there. The pilot jet is responsible for controlling mixture from idle to 1/8 throttle. The mixture screw on the side of the carb is for fine tuning the pilot jet.

Try a new plug chop after letting it run at idle ONLY and see what your results are.

Remember the pilot jet is still adding fuel even after you've opened the throttle more. So a pilot that is very lean or very rich can throw off your WOT plug chop readings.

[LONG-ROD]

agreed that several plug chops must be performed. I would start with the main jet. If you dial your needle in first then it will be off when you change your main. leaning the main also leans the needle in a less dramatic way then clip position. and always do your chops on really clean filter. also check your coil wire where it goes in the plug cap. If it is corroded then strip it so you have good wire showing. This will make an incredible difference. many people bypass there needle setting out of lack of knowledge. you ride 75% of the time on the needle, so if you are lean there she can blow, and if you are fat she will be a dog.