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California Plug Chops and YICS Tuning

Discussion in 'XJ Technical Chat' started by day7a1, Jul 29, 2011.

  1. day7a1

    day7a1 Member

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    I recently installed real mufflers and OEM air filter, did some tuning by ear, and after riding to work the other morning (25 miles, freeway for about 10) the idle was at 3000 rpm. No problem, it just wasn't warm enough yesterday when I set it....turn it down. Turned it down to what the tach says is 1000 (I'll get back to that) and it does the characteristic "slowly dies", where it just can't get enough energy to keep going. Bump up the idle a little, pay attention to the throttle, get home ok, start to sync and tune.

    Clean out YICS, insert (more like stuff) rag soaked in Amsoil 80w90 gear oil, and sync. Didn't have to change a thing (didn't blank the YICS last time, so I really thought that was the problem) Sync's perfect at about 1100- 1300 rpm (wouldn't idle very well any less and the tach just isn't that precise!). Tune by ear with the YICS still blocked....thing idles like a sewing machine at 950.....awesome...or so I think.

    Reinstate the YICS holes....slowly dies. ugh. So I continue tuning. Have to pull the screws out a half turn just to play. Turn the idle down, tune, turn the idle down, tune, etc. until it will idle at 950 (or so the tach says) and any change in or out of the pilot screw on any cylinder will mess that up.

    Go to work the next day....starts up a little hard, but mostly because it needs a little choke to start, but even a little choke is too much choke. It starts, doesn't need any choke a mile later, and feels GREAT. No hesitation when I hit the throttle at all, no popping, no bogging....but I keep wanting to take the choke off. Just FEELS too rich, especially just off idle. So I do a plug chop, once at idle, second accelerating down the alley in too high a gear with my wife and I both on using just a little throttle, get it up to about 5k and "CHOP"...

    [​IMG]

    I think
    a) my tach is off a little, my friends at work that ride bikes both agree that when it says 1000 rpm, it's a LOT less....1500 rpm seems correct though.
    b) the gas here isn't good for plug chops...every single one i've ever done looks almost exactly the same.
    c) i think I should retune with the YICS blocked, and up the idle until it doesn't stall....
    what do you think?
     
  2. RobDrech

    RobDrech Member

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    Those plugs look too old to me to get any real good chop info out of them
     
  3. dirtymaxim

    dirtymaxim New Member

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    Try using a colortune. I had similar problems for years, that fixed me right up.
     
  4. day7a1

    day7a1 Member

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    Don't let the rust fool you!

    They're not due for renewal for a couple of months....I live, work, and play by the ocean and use it as my primary vehicle.

    I'll be getting a colortune...but I like the idea of being able to tune it by ear. It seemed to work really well, actually, it was no longer guesswork, I could clearly hear the difference between a few degrees in or out.

    Being a bit lacking in colorvision, I like to use my ears more anyway!
     
  5. day7a1

    day7a1 Member

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    I guess I should add...the old plugs looked just like that, the new plugs (those) looked like that when they were nearly new, and of course they still look like that.

    Rich or lean, doesn't ever seem to matter!
     
  6. RobDrech

    RobDrech Member

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    gotcha.. thanks for the clarification.
     
  7. Ravenz07

    Ravenz07 Member

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    Doing a plug chop requires new plugs that are only used during that "chop" run, and not the driving to that occurrence.
     
  8. Polock

    Polock Well-Known Member

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    first, get some never-seize on those plugs and use it religiously.
    2 &4 have a problem, they use the same coil, swap the wires around and see if the problem follows the coil (all the wires)
    the tan color only happens by a valve, i forget which one,mark the plugs with a marker when you put them in, if the plug strap is where the color should be you might miss it.
    lack of soot on 2 says it wasn't firing at all
     
  9. day7a1

    day7a1 Member

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    That kinda makes sense, sorry it's the first time I've heard it. I went way back in thread history and looked for it and did find a couple of references. I did see your question, but no answer...I'm guessing you found the answer elsewhere? I did think that cleaning them might next be in order, to get what carbon deposits are on there off of there. Since they stay looking like this, I didn't bother putting new ones in for this particular attempt. What's the best way to clean plugs?

    I'm pretty sure there was a post somewhere that showed that even a couple of combustion cycles would change the plug color....I'm just not seeing ANY change, even when I KNOW it's running rich! I used to be able to smell the gas! I'm not convinced that plug chops are accurate unless certain conditions are met, but I'm not sure what those conditions are.

    Polock: 2&4 don't share the same coil on my bike...but what common problem do you see with those? The whiteness i'm guessing. I'm fairly certain that all 4 are firing....they haven't always, and the thing will maintain an idle at ridiculously low speeds.

    I've gotten several comments, and I know it saddens everyone, but the environment here is BAD for this bike, I know. There are 3 in the parking space and the Harley is the worst looking, steel spokes! I will likely be it's last owner. I'm a block or less from the ocean 24 hours a day, even if I had a garage at home it would only be in it 1/4 of the time! I use grease, anti-seize, and wd-40 religiously, and a cover on most nights.

    I think I'll try to clean the plugs a bit and try it again tomorrow. I'll also make sure all 4 pipes get hot at the same time. I guess I'm not so much doing a plug chop as a plug read, the only time they've been dark is when the PO was running BP5ES's and no boots and the choke had to be fully on just to make it run. It seems to run pretty good, I'm just trying to get the starting and idle right. I might need to get a laser tach... :)
     
  10. Polock

    Polock Well-Known Member

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  11. day7a1

    day7a1 Member

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    Ahhh...there it is. I've seen that before, thanks polock!

    To quote some relevant points:
    Not sure about that last line, what's the difference between "very light" and "just offsets the white"?
     
  12. bigfitz52

    bigfitz52 Well-Known Member Premium Member

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    It sounds to me like you're kind of missing a step.

    You blocked the YICS, and said the "sync is perfect."

    What were you using to vac sync with? The discussion is in regard to mixture adjustment (ColorTuning/plug chops) but it doesn't sound to me like the motor is sync'ed yet.
     
  13. day7a1

    day7a1 Member

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    Inverted two bottle manometer with a manifold....

    http://xjbikes.com/Forums/viewtopic/t=33119.html

    I synced and adjusted the pilot screws concurrently. #1 was a little off, but not by much, and the screws needed to be turned IN a little bit, I had previously done a quick "let's see how this works" tune where I found the screws to be about 2 7/8 turn out, with the YICS blanked they were a little more than 2.5 turns out. I didn't check how much out the screws were at the final analysis, because just a LITTLE BIT of movement either way destroyed my idle! But it must be a little over 3, since I turned them from 2.5 to 3 just to get them in the ball park. I'm actually pretty excited that I can notice that much difference within 1 turn of the screws....I hadn't been able to notice that previously, I had just turned them out until it felt right, started the way I wanted, and didn't stall out. But I messed that all up by bringing it back closer to stock! :p

    I would just adjust the screws, lower the idle, adjust the screws, lower the idle. It got to a point where adjusting the screws either IN or OUT would affect the idle negatively. Then I made sure it was still in sync. It didn't sound like it, but it was, and I think it didn't sound like it because the idle was too low (or maybe it just LOOKED like it was because the idle was so low...hmmmmm.)

    I think I have two problems....
    1) I'm (actually WE'RE) looking at the wrong place on the plug to determine mixture. Of everything I read online last night, including the link polock posted, the GENERAL CONSENSUS was that it's the base of the threads that you need to look at, NOT the porcelain. Makes sense if you think about it, the porcelain should be getting hot enough to clean itself of the deposits that everyone else is looking for! Also, I guess there is a little ring around the BOTTOM of the porcelain that will indicate your mixture too....but you need a $100 tool just to see it!

    2) My tach isn't very accurate below 1500 rpm. I know it's not very precise, you can fit the needle between the 500 and 1000 marks, when it's right at the bottom of the the 1000, where you might think it's 950, it sounds much more like 500, and 500 is pretty well stopped. I've been trying to borrow a handheld laser tachometer. I couldn't find one to borrow, but they have one at Harbor Freight for about $30. That would also help tune "by ear" too, since you could notice any change in rpm.

    I think if I tune by ear, with the YICS blocked, and set the idle right, I don't think it will stall out. And I'll get new plugs just because they're inexpensive. And it's not bad right now. It actually runs better than it ever has, just a tad rich. But even that's ok in the San Diego Summer Freeway Free-for-all.
     
  14. bigfitz52

    bigfitz52 Well-Known Member Premium Member

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    Ahh, a masochist, gotcha.

    1. You're right, it's a debate I never want to start again because of all the "traditional" thought so I leave it alone.

    2. Just turn the idle up a tad if blocking the YICS drags it down too far; then turn it back down once you're done and the YICS is unblocked.

    BE CAREFUL on those City freeways! Watch your mirrors; maintain 'situational awareness.'
     
  15. day7a1

    day7a1 Member

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    No, I would be a masochist if my colorblind self tried to tune with a colortune! A quick flash of color from a small window? No, thank you. I'll use my ears, please!

    I went out and tried it again just now. A little experience goes a long way. This time, instead of stalling out when I removed the YICS blanking tool, it went up in rpm. Turned it back down to what I now believe to be the right rpm, but didn't get to ride it...while taking my vacuum caps off #4 decided to end it's own life. It was on it's way out anyway.

    I think the difference this time was knowing that the idle speed read wrong...I adjusted that by ear, too. I tweaked the idle knob a LOT more this time around, going from sync speed to tune speed everytime I wanted to make an adjustment. I'll go get new vacuum caps and plugs tomorrow.
     

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