Please help me diagnose

Discussion in '2-Stroke Engines' started by Marktur, Jun 17, 2008.

  1. Marktur

    Marktur Member

    Hi all,
    OK, the motor idles fine, but a bit slow on acceleration (getting on the pipe), and at WOT or cruising speed, I feel a bit of if I'm not feeding it enough gas.

    I have not pulled out my plug to look at it - it's still warm from riding, but it's a new NGK plug as recommended.

    I have the carb set (e-clip) to the lowest (closest to the bottom) because they say that's the setting for my zone in the world...but I'm starting to wonder.

    At idle+ is jerky - I don't know if this is normal or not, but I can't just let it idle wants to go. At mid-range, and say 15mph it starts to really wake up, and I don't feel this at half throttle.

    I know I still need to check the ports and gaskets, but I've also seen conversation stating that this has to do with the neeedle in the first place, or the diameter of the jets -- which is just beyond my level of knowledge...but not afraid to follow directions. :)

    Thanks for your help, and ask away so you can help me figure this one out.

  2. srdavo

    srdavo Active Member

    with your clip set at the lowest might be pushing too much fuel in at WOT.
    try moving your e-clip one setting. (test drive)
    then move it one more setting....try that.
    then pick what's best....and tell us about it!!;)

    didn't you just change to a 40t sprocket? always lose some on the bottom end, when you gain on top end. that's prolly why your seeing the jerky/chugging-lugging at low speeds. (you are right in saying "it wants to go")

    IMO, don't alter your jet or needle. and don't worry much about porting.
    just be "happy" everytime your "happytime" starts & runs!!
    (see my
  3. Marktur

    Marktur Member

    Hi Dave,
    No, I think this has been around since day 1. It's just that with the new sprocket, I can finally open it up without the shakes and sounds (over revving), and I thought it would go away if I could run wide open (thinking maybe vibrations were the cause, since I wouldn't turn it all the way open - I was blaming it on myself).

    I thought the lowest setting on the needle was for a leaner mix? Moving it up one makes it richer...I'll try it in the AM before my ride to work, let you know. That brings it back to stock, right?

    For the porting, I just want to see how much is being blocked...if it's significant, I can improve it.

    Approx. how fast should I be going on flat ground, 220lbs, WOT? I think it will top out at 30 in enough time. Not that I want to go faster, I just want to make sure my motor is the most efficient.

    And on a really good note: My last month gas bill was $198...probably half of the month before! I can't wait to see the bill in July!!!! Sticking it to the man!
  5. srdavo

    srdavo Active Member

  6. Marktur

    Marktur Member

    So I'm running as RICH as - can't wait to change that around!
  7. Marktur

    Marktur Member

    Whoops - according to Dave's first link, I'm running as LEAN as possible - clip is closest to the END of the needle. I'm going to move it one notch at a time...I'll move it back to the stock/break in position (second down from the end) and ride it today...if I see a good improvement, I"ll move it one more and see if it gets change at a time. :)
  8. Marktur

    Marktur Member

    OK, so I went to the SECOND notch from the end from the first notch closest to the end.
    My top end smoothed out, especially while decelerating. I didn't feel the need to pull in the clutch every time I left off the gas.

    But the bottom end got fat (rich). Idle got a lot slower - I have the screw turned in just about all the way now. (Is that right?) Slower acceleration, and at mid range switching between 2-stroking and 4-stroking. I think my top end is a bit less, too...

    I know everything is a trade off...but man, I wish I had another rider close by to have something to compare it to. :(

    So I think the next step is to pull out the manifold and muffler, and make sure I don't have **** in there blocking things, etc. I also thought that I can pick up another stock muffler and experiment with cutting the manifold and making it longer using rubber hose (like we do with tuned pipes on RC airplanes/cars) to see if I can get the motor to "stay on the pipe" in a much wider throttle range.

    Am I chasing my tail here?

    Again, not looking for speed, but efficiency and smoothness.

    Also - do you recommend that I change out the spark plug wire?

    What else can we do to make the motors run their best?

    (Please don't think I'm unhappy or complaining - I'm a software guy, and I don't get to tinker with my hands as much as some of you - so it's actually enjoyable as a hobby for me.)

    Thanks! :)

  9. How bout a pic of the spark plug......
  10. Marktur

    Marktur Member

    I would love to show my plug but unfortunately, the sky is I had my wife pick me up and I put the bike upstairs in the office. It's going to smell like gas in the AM, and my partner is going to ***** like a little girl....and I'll walk around with a smile on my face all day!

  11. Jerky can also be a sign of Spark problem.

    Kind of like some one throwing a switch on and off from your coil.

    Good idea to check wires for possible grounding issue or poor connections.

    Just a thought.


  12. Marktur

    Marktur Member

    Hi Guys,

    OK, I pulled the plug this looks rich - mostly black. Before when I looked at it (before I richened it up) it had that nice chocolate color. I also used a lot more gas than I had expected...the tank was about 3/4 full, and I probably put on about 30 miles...I think I should have gotten better mileage - so I went back to the leaner (leanest) setting: I went back to the notch closest to the end of the needle (leaner) and I think it's happier there. Better acceleration, I think.

    Here's what's interesting - at 3/4 throttle, it will slowly go up to about 27mph. Motor is not screaming which is good...but it won't go faster - as I open the throttle more, it seems to bog a bit, ie, doesn't slow down, but doesn't go I'm thinking that Bob might be onto something.

    I made sure the plug is connected well, and I can visually see that the blue and black wires are connected well (crimped, not soldered), but they pass the "tug test".

    So...plug wire? I certainly don't mind changing that, but silly question: how? Isn't the CDI sealed?

    Also - plug gap - I never set it. Just popped it in. It's the NGK plug, what should I set the gap to?

    Another hint - for the first time in about a month, my speedo reset! It happened 2 days ago - I forgot to turn on the fuel lever....when the motor died, it reset the speedometer. Weird, huh? It hasn't reset since....also, my light failed. This is on a completely different circuit, not using the bike as a ground or anything. These things may all be completely unrelated, but I figure I had better tell all of it to get a good diagnosis. :)

    Any help is appreciated, guys. And Thanks. And please pardon my ignorance....I'm trying! :)

    Still waiting for Fedex to show up with my Springer Forks!
  13. The plug wire just screws into the CDI, plug gap s/b between .020 and .025 You have to remember that with thet sprocket you are running now you are putting more strain on the motor because of higher gearing. Therefore the engine might not have enough torque to go any faster. A good comparison would be riding your bicycle in 5th gear all the time there is a point at which you cant go any fatser and it is alot harder, and you might be able to drop down to 4th gear and actually go faster. With that leaner setting just watch that plug, 2 stroke engines dont like lean conditions, especially in hot weather.
    Last edited: Jun 20, 2008
  14. Marktur

    Marktur Member

    Hi Mister - it was set at .022, so that's fine.
    I was able to tighten the plug wire - cdi connection - almost an entire turn. So I took it for a short night ride list night. I think it ran better, but still not 100%.

    I received intake and exhaust replacement gaskets, and they will go on today, and I'm going to also pull out the o-ring and use RTV to make sure I have everything sealed up properly. The gaskets from DAX are nice and thick. I will coat them with RTV on both sides when I install as well. Once the intake and exhaust are off, I'll also hit it with the dremel if necessary..if you know of a thread for porting with pictures, please point me in the right direction....

    BTW: New light is great! Haven't recharged it yet, and I'm sure I have over 1 hour on it. But last night, in the dark, it lit the road pretty darn good. I still have the Bell light attached - I thought the blinking LEDs would also help...but it's got a regular light as well...definintely not light enough, and when the halogen light is on, completely outshines the Bell light.

    My springer forks came in yesterday finally from Spooky. Pretty Chrome! Should really make my ride software, I hope. :)

    OK, I'll post later...going to fly my planes this morning.
  15. crabdance

    crabdance Member

    Glad you got your fork in Mark... once you get it on take some pictures and let us see.

  16. Marktur

    Marktur Member

    I'm not sure if my last tests (after porting the exhaust) were in the best conditions...100% humidity and slightly drizzling...

    Today I rode into work...the motor was REALLY happy...I cruised in at an easy 25mph, with plenty of power to spare and go faster if I wanted to.

    I will do the same port work on the intake tonight, and then I think I'm done with messing around with the motor, and I can just ride ride ride...(and do regular PM).

    I think I can finally get my concentration back on track with my giant scale Cessna 310 RC Airplane and get it finished up and in the air in the next couple of weeks.
  17. Do they have a club down there for the r/c planes? I go and watch them race here, they have a club. I believe it is every 3rd Saturday. Pretty cool!!!!!!
  18. Marktur

    Marktur Member

    Yep - in fact the largest club in the USA with over 500+ members.

    Great club, and within motor bike distance from my house! :)