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TO MUCH FUELL ON THE PLUGS 618

in 2 Stroke Technical Questions 13 years ago

  • Re: TO MUCH FUELL ON THE PLUGS 618

    by » 13 years ago

    Bill I done that and it works just the way you said it,
    Now is there a problem if the large screws with the spring do go all the way in? Because the one is all the way in (the one that isn't I had to unscrew it about a turn and 1/2 to match the slide stop of the other one as the stop wasn't the same hight from the bottom of the carb on both of them) and I still shy about 200 RPM to get it iddle at 2000, On 2000 I beleive a minor vibration that I still have will go away, I haven't change the needdle clip from the last position to 2nd position hoping to reduce the richnrss on the plugs as my primary objective is, I will do that next after I hear from you and get the hight of the slide out of the way.
    Regards
    Yanis
      
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  • Re: TO MUCH FUELL ON THE PLUGS 618

    by » 13 years ago

    Yanis,

    If the idle speed screws are all the way in and you still can't get the idle up to 2000rpm, Change the needle clip position as we talked about. This will lean the engine and probably speed it up. Then you can set the idle speed. It sounds like you are way too rich on the mixture because of the needle setting and the engine just doesn't want to run at low speeds.

    At 2000rpm, you are getting into the range where the idle circuit is used less and the jet needle is beginning to control the mixture. Just remember that from 0 to 1/8 throttle, the idle circuit controls everything. At about 1/4 throttle, the jet needle and needle jet begin to control everything. after about 3/4 throttle, the main jet does everything.

    I think if you get the mixture leaned out and the EGTs up where they belong, you will have much less problem with the idle.

    One thing I haven't asked. Are you using the enrichener (choke) on the carb? If so, you need to make sure it is all the way off when not in use. If the enrichener leaks or does not close all the way, it can also cause a very rich mixture.

    When you lean the mix, the engine may want to overspeed. The only way to control maximum RPM is with prop load. You may have to repitch the prop to keep the max RPM down.

    It is looking more and more like this is just a combination of many little adjustments that are gradually being fixed.

    Bill.
      
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  • Re: TO MUCH FUELL ON THE PLUGS 618

    by » 13 years ago

    Dear Bill, I receive your latest and I am very happy with all your suggestions, I am working on them and I do beleive we are on the right track,
    Unfortunately my needles only have 2 setings, I know new ones have 4, Anyway mine was set to the bottom one and I raised the clip to the the top, I run motor about 5-6 time few minutes at the time and beleive it or not the plags started to clrear up from the black residue also is changing color to the brownish and seem dryer,Can be the needle or can be the additive I pure into the gastank,
    CHT are very close together, EGT VERY CLOSE TOGETHE and all these from 1700 RPM TO 4000 + I was keeping an eye on the cooling and shut it down any time was geting to the hot level as I had the plane in the hangar.
    One question I notice that nothing is holding the needle just laying there under the white cup? how that works that the way it should be? OR I MISS SOMETHING, (hope not) lol,
    Stiil haven't got the desired 2000 RPM without raising the handthrotle, I may be able to do that by raising the pistons a little from the adjusters on top of the carbs i will try that. I plan to fly it tomorrow and will give yoy a better report,
    Regards
    Yanis
      
    Report

  • Re: TO MUCH FUELL ON THE PLUGS 618

    by » 13 years ago

    Yanis,

    It is the needle. Adjusting the needle clip makes a BIG difference in EGTs.

    The needle just sits in the slide and the white cup and spring hold it in place. There was an upgrade for the needle some years ago that suggested adding a tiny O ring on the needle right on top of the needle clip. There were some problems with the needle rotating in the needle clip and actually causing the clip to wear the needle in two from vibration. The O ring stops this from happening. If you don't have the O ring, It is a good idea to check the needle for wear in the notch where the clip attaches. I would add the O rings if you don't have them. Adding them later will not affect any of your adjustments.

    The slides should sit on the big idle speed screw at idle but it is no real problem if they don't. Use the adjusters on top of the carb if necessary but just be sure that the slides are the same height at idle and both begin to rise at the same time as you apply throttle. This will keep the EGTs very close to each other.

    Now that you have the fuel mixture leaned out, be sure to watch the EGTs and RPMs at full throttle so you don't get too fast or too hot.

    Good luck,

    Bill.
      
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  • Re: TO MUCH FUELL ON THE PLUGS 618

    by » 13 years ago

    Hello Bill,
    I owe you this report,
    I took my bird up this morning, Weather was bad ang got worst after take off, I had to fight and play with the unexpected gusty winds, Stay on the patern for about 20 minutes I never went over 6000RPM but everything was good, Was running nice smooth and cool, EGT on both was 1000 to 1050 and that having 75%-80% throtle on most instances and less anytime I was reducing power, After landing i took of a couple spark plugs and they was cleaner than yesterday, I am very happy with the results and your assistance was the ultimate, Thank you,
    The needles do have the O ring above the clip, I will leave things the way they are now as I am happy with all we did, Little by little later on all going to smooth out, If an issue arise I will report to this wonderfull and so helpfull forum, I have printed out all your inputs and will be usefull in the future.
    Thank you again,
    Regards :P
    Yanis :P
      
    Report
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