idle mixture problem / colortune issue ? / Going insane ?

[psycoreefer]

I agree, popping at idle doesn't always mean lean - it can be caused by too rich also, especially with a "free flowing" exhaust system.

[TDodge7]

ok , so I just went for a ride around the neighborhood using only less than 1/4 throttle and then pulled up in front of my house and listened to the idle for a bit . While I was listening to the idle it kept slowing down ....I have good news and bad news , the good news is that all the plugs are one uniform color now for the most part (#3 is actually kinda tan if you can believe that) , the bad news is they're very sooty , I guess I got it a little too yellow on the colortune . I guess I should try a half turn leaner on each , re synch , and see what that does .

[bikerphil]

You said you drilled the air box, hopefully in the center filter area. Do you have a new air filter in there? I'd try only 1/4 turn leaner steps with the idle mix screws.

[TDodge7]

yes , I only drilled the center of the air box . the filter is a freshly cleaned and oiled k&n . I can get it too rich or too lean , but getting it just right is a challenge . I just came back in from trying again , I've got it sounding better at idle , but now the plugs aren't uniform in color after riding around under 1/4 throttle some more ....even tho I colortuned to the same color which was just out of blue where it's still somewhat blue but with a little yellow in it . I have a feeling it's a hair too lean tho , and I'm not sure why plug 4 has a white tip now yet plug 1 is still sooty . I may go pick up a new set of plugs , these have changed so many times they're of little use to me at this point . I just wish this was over with , I want to be riding , not wrenching , I lost all of last summer wrenching on this bike and it's still not done .

[Larrym]

Disorder in the Court: Three Stooges

I'm there with you on all this. Myself, something like this would just really bug me. I wouldn't be able to relax unless I knew what was going on. An odd trait to have but sometimes it does have its benefits.

I'm trying to "see" what you see about your plugs but without pics there's a lot of room for misinterpretation. Like when you say "sooty" do you mean the tips of the anode, the cathode, the porcelain insulator, or the round metal base. Sooty at the metal base/ring is an area related to low speed/idle.

Next best thing to your original pics is this:

http://www.ngksparkplugs.com/tech_su...qs/faqread.asp

Would help if I saw exactly which "selection" from the plug chart best matches what you see with your own eyes. At least for me...

Based on the tune-ability symptoms you describe I'd want to make you remove your hat and swear on a stack-o-bibles that the idle/pilot jets are the right ones for the year/model of your bike.



They look the same from an arms length. But If you "solemnly swear" that you've confirmed this isn't happening then there's one more possibility that comes to my mind.

If you had a leaking intake valve seal then the air/fuel "mixture" might not just be those two. Add a little oil and that would go a long way towards explaining what you're seeing. I have a "leaky" seal on #1 cylinder and so that plug is always a little off as compared to the rest. Not a dealbreaker yet but I know it's responsible for what I see when I look at the plugs.

Next time you have the carbs off I'd look through the intake/inlet into the head and have a gander at those valves. Tough to tell cause they're always awash in a fuel mist which tends to clean-as-it-goes-along.

Another tell-tale would be oil consumption yet good compression readings.


If it is a leaky valve stem seal then my choice is to live with it until I really gotta do something about it. May not be much wisdom in that but I'll be riding this season.

[TDodge7]

I'm trying to "see" what you see about your plugs but without pics there's a lot of room for misinterpretation. Like when you say "sooty" do you mean the tips of the anode, the cathode, the porcelain insulator, or the round metal base. Sooty at the metal base/ring is an area related to low speed/idle.

remove your hat and swear on a stack-o-bibles that the idle/pilot jets are the right ones for the year/model of your bike.

when I say sooty I mean every area exposed to the combustion chamber is charcoal black and dry

here is a picture , I can't seem to take a decent one with the camera


plug #1 is how they look when I set the plugs to cobalt blue

plug #2 is how the plugs look right after I make the mixture slightly leaner to correct it from being too rich

plug #3 is the best looking I've been able to make them look , but it usually doesn't stay this way and will either migrate towards plug 2 or 4 . There is a second version of this plug where the tip is grey instead of brown but it also seems to migrate to #2 or #4 eventually .

plug #4 is sooty and dry , this is what I get when I set them so the colortune shows yellow

there doesn't seem to be much in between #1 and #4

I had been using new sets of plugs for every test but that got expensive quick , so I've just been re-using these and cleaning them , or letting the engine clean them up (mostly what #2 looks like)

pilots are 42.5's stock for these 79 carbs .

No abnormal oil consumption and I don't appear to be burning any oil , no puff of smoke when it first starts , no smoke on high rev's .

so is there no way to check how you're running at idle ? I know you can do a plug chop to check tuning with the throttle open , but how am I supposed to check plug color at idle . I assume that's what I'm going to have to do since setting it at the normal places doesn't work . This has me so stressed out , this is supposed to be an afternoon thing and it's taking me forever , I just want it to be done so I can ride .

[WMarshy]

This post has some good pix of plug color...

http://www.xs11.com/forum/showthread.php?t=2712

[TDodge7]

When I colortuned and set them all to a bright yellow ring they all came out like #4 , now that I've changed the tuning again cylinder 1 looks like #4 , cylinder 2 looks like #4 , cylinder #3 looks like the brown version of #3 and cylinder 4 looks like #2 , I thought I had them all adjusted to between blue and yellow but I guess I didn't get them that close .

plug #1 is usually the richest and plug #4 is usually the leanest (carb 4 once had a broken mixture screw tip but I managed to get it out without messing the hole up too much , there is a new mixture screw in there now , but I can still adjust thru the entire range with it)

the only one that looks like what I have on that spark plug chart is carbon deposits .

[WMarshy]

Sorry in advance b/c I havent read the whole thread but, are you sure all the needle/clips are in the same position?

[TDodge7]

yes they're all in the stock position (I forget what that is off the top of my head but I researched it many times when I had the carb apart chasing jetting problems in the past ) They haven't been messed with since .

It just seems like there isn't much between too rich and too lean , you'd think if I can get it too rich and too lean that there should be a perfect mixture somewhere in between , but I can't seem to find it .

[WMarshy]

After watchin you vids on the second page I would tell ya to stop your b*tchin and ride the damn thing. I wish mine would idle that smooth. Remember, its always better to be too rich than too lean! I think your spending too much time nit pickin at this point. I mean, since Ive owned mine its never had a sync or f/a (colortune) adjustmen done and it seems to run good for me, but aparently what I call good us probably sub satisfactory to you.

[TDodge7]

it started fouling out after that video because it was so rich , hardly a good setting .

[Rasputin]

Just wondering how many turns out you are with your screws. Also have you removed them lately and confirmed that the end of the needles have not been broken off. If you have said in previous posts what the compression is I have missed it, that may also be helpful with this problem. Mostly just thinking out loud here

[TDodge7]

no mixture screws are broken off or else I wouldn't be able to change how the colortune looks on every cylinder . I forget what the compression was off the top of my head (had to borrow the compression tester) but it was uniform across the board .



I guess my two most important questions now are :

Since I can get it too rich or too lean there has to be a correct mixture in between them somewhere correct ?

Since all the usual ways get me too rich or too lean then is there another way I can adjust ? Sometimes it sounds like a lot of people are just doing it by ear and then letting it slide without ever knowing how it's really running . Clearly mine is more picky , and it may come down to me just adjusting each cylinder 1/4 turn by 1/4 turn , but if I'm not going to be able to read the plugs by just sitting there idling then what should I do , ride around the neighborhood under 2k ? I'm starting to run out of ideas .

[Rasputin]

I usually take mine out for a good blast down the road. I go high speed, low speed , all ranges for 15 mins or more. Then I come back and let it idle for a minute or two. That pretty much tells me the color of the plugs at idle, the higher speeds tend to clean the plugs up for me anyways. It works for me although other may have differing opinions. The reason I asked about how many turns out the screws are is that if it is a smaller number such as 1- 2 turns then the jets may be too large. If it is 4-5 turns out maybe you need to have larger jets. If the jets are out by one size it makes a difference in the adjustability.