peugeot trekker fuel mixture issues

Discussion in 'Scooter Tuning' started by CEEKAY_NG, Aug 2, 2011.

  1. CEEKAY_NG

    CEEKAY_NG New Member

    Messages:
    25
    Rides:
    Peugeot Trekker 50
    hi all!
    i finally done it and bought my 70cc polini sport kit fitted it and ran it in last week, i then got my stage 6 manifold and 21mm carb, fitted them on yesterday and it wont start? well it did but then cut out so i adjust the screws to standard and nothing? i checked my spark plug and it was soaked! i tried it on the grill;] put it in kicked it over 1! and soaked so it is to rich! but i have tried to adjust the screws but nothing.the main jet in was the one that came with it a 75 i think? but its confusing me, anyone know a way to adjust the mixture? or tips of how to do it let me know! and also on the TNT carb it came with a vacuum connection, but so did my inlet manifold? so does it matter which one it connects to? and help i would be much gratefulll!
    :)
     
    CEEKAY_NG, Aug 2, 2011
    #1
  2. Jonnymarrw00t

    Jonnymarrw00t Moderator Staff Member

    Messages:
    3,240
    Rides:
    Piaggio Zip 05 plate
    Down jet. You need a smaller jet for a bigger carb.
     
    Jonnymarrw00t, Aug 2, 2011
    #2
  3. Merlin

    Merlin Old School Biker

    Messages:
    2,305
    Rides:
    2007 TKR WRC 50
    Hi,

    I can help here.

    You need to either 'T' together the two vacuum connections and take the third one to the fuel tap, or put a short length of sealed off hose on one of them. A 'T' piece from a aquarium shop would work. If you don't do this, I don't think you will be getting enough vacuum to open the fuel tap, as the manifold one will be cancelled out by the carb one.

    Also, you need to adjust your jet and needle settings. The air screw just alters the idling mixture. If the plug is soaking wet with fuel, it's way too rich. Put the throttle needle circlip on the highest groove of the needle and try doing a 'plug chop'. This is where you run the engine up to full load then cut the engine and look at the plug.

    You are looking for a plug colour between a Ginger Nut to Rich Tea biscuit colour. Black and sooty is way too rich and if you still get that after adjusting the needle, you need to jet down, adjust the circlip to the middle groove of the needle and try again. White is too lean and you need to move the circlip down the needle to raise it up and richen the mixture. Too lean a mixture and the piston will overheat and you may burn a hole in it.

    The tapered part of the needle is the mid-range mixture and you don't generally need to get concerned with that, but getting the top end mixture right is crucial, if you want to save fuel and don't want to burn a hole in your piston. Get it right and your machine will fly.

    If you have any questions, just ask.
     
    Merlin, Aug 31, 2013
    #3
  4. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

    Messages:
    14,276
    Rides:
    et2 monster
    jet/needle have NOTHIN to do with starting the bike... the pilot et is too big. block the manifold pipe fittings and use the on on the carb (just like std) if the plugs soaking then te carb/engine is getting fuel, so the tap is pen... 2 vac fittings? me thinks not. waste of time... also, going by the plug is NOT an accurate way of jetting, its ONLY gonna show up full throttle and that's ONLY gonna show up if you do a proper plug chop (new plug, full throttle, turn the bike off while at full throtle and hold till the engine stops... check the ring at the base of the electrode) also, ginger nut to rich tea is LEAN AS FUCK in a 2t... chocolate brown at minimum... even then the old plug isn't gonna show up general running, rich up top and so lean it blows at half throttle will sow a perfect plug, so do NOT jet va the plug. plenty in the guides section about jetting.... generally ignoe everything bar the mixture and pilot jet first (no throttle means the needle and jet do fuck all) once the idle mix is correct, work on full throttle (roller first, then work out the main by getting it rich, so its faster with a lil less than ull throttle then go down a size till it stops doing this) then ajust the mid throttle position.. it will alter the top end so you will be changing jets again once the middle throttle is done, then re setting the needle... your looking for the happy medium... or pay someone ith a dyno/experience to jet it.. wont take an hour.


    as of the above.. its guesswork and totally wrong.. you REALLY need to pay attention to mid throttle mixture, this is where engines blow/are ridden the most.

    also, with carb increases, you usually need to drop roller weight. roller issues are ALWAYS confused with jetting issues..



    so as per the rules, don't and out duff advice.. it wont help anyone. don't guess, and don't recycle what you've read elsewhere... the tunning section is for people to aswerwhen they KNOW what there doing and do it day in day out... the above advice is wrong and will result in blown engines. don't guess!
     
    MiNoR cOnFuSiOn, Sep 2, 2013
    #4
  5. Merlin

    Merlin Old School Biker

    Messages:
    2,305
    Rides:
    2007 TKR WRC 50
    I'm not offering duff advice, I raced 2-strokes back in the late '70s and early '80s. If you are using smokeless 2-stroke this is what you should see, as any remaining oil will burn off. You'd only get a chocolate brown colour if you were on old mineral-based 2-stroke and most stuff these days is synthetic and smokeless. I suppose you've never used a Colortune plug for setting mixtures either, so what do I know?

    If someone could give me subtitles for his post, I'd be obliged, as I'm too old for text speak.
     
    Merlin, Sep 2, 2013
    #5
  6. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

    Messages:
    14,276
    Rides:
    et2 monster
    lol, wind your neck in... the 70's were 40 years ago.. your info/post comes straight out of a 4t tunning manual.. as for mineral/synthetic based oils, there is VERRY little residue ether way and the colour will no9t change.. whatever oil you use rich tea is too LEAN for a 2 stroke.. no i dont use colour tune, halfords tunning right there.. the engine tells me if its lean or rich as i know how to listen, i NEVEr use the plug and have set up hundreads of scoots pre dyno, to find i dont need to change a thing roller or plug wise... your information is full of holes.. and with an auto especially going by the plug, can give you VERRY lean mixture at mid throttle (where there ridden most of the time) so again, its bad advice.. i think i covered everything pretty well in my last post. as for my txt speak, dont like it then fuck off... check who's name is next to "owner" on here... and wind your neck in.
     
    MiNoR cOnFuSiOn, Sep 9, 2013
    #6
  7. Merlin

    Merlin Old School Biker

    Messages:
    2,305
    Rides:
    2007 TKR WRC 50
    OK, so please being me up to date then with modern techniques. How exactly are you checking the mid-range mixture, to ensure that it doesn't lean off before the main jet kicks in fully? Do you monitor the CO emissions or something, or do you just listen to it, as that doesn't seem to be very precise if it's all based on your ear, although I acceot that you can hear 'pinking'. Can you really 'hear' a 12.5 to 1 fuel/air mixture ratio?

    How exactly does your 'ear compare to actual dyno and emissions tests?

    I'm not trolling, I'm serious, I want to understand what makes the way you do it so precise and right, when you could look at the flame directly to judge the mixture using a Colortune plug.
     
    Merlin, Sep 9, 2013
    #7

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