another bog question

Discussion in 'General Tuning' started by jay88, Dec 31, 2010.

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  1. jay88

    jay88 Member

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    i do apologize MiNoR cOnFuSiOn and i did take the advise and it did get my bike up and going again thanks to this site and a filter on a 70 lol does float my boat i like the noise lol but now i have ran into another prob i never knew a carb can course so much sh*t cuz now when i full throttle the engine tone gets deeper and i thought it had a 110 main jet but it has a 115 main jet with the e clip at the top and air screw 1.5 turns out like terro said but i dont know what main jet to put could u tell me a ball park figure on what size to use i know theres loads of tutorials but they dont make no sence to me am thick as sh*t when it comes to carbs but like i say i do apologize MiNoR
     
    jay88, Jan 14, 2011
    #21
  2. bertie

    bertie Active Member

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    1,440
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    '93 Skipper LX125
    Your jetting is WAY off mate! A 115 jet in a sport 70 is just crazy, no wonder the bike doesnt want to rev because its being flooded with tons of petrol lol!

    You need to downjet to around 78-80 (which is still TOO big for your setup), then setup the transmission (rollers and clutch springs).. THEN you can finally setup the carb.

    You must have mistaken roller setup for carb setup, Ive done it before where I banged on a open filter, upjetted 10% and it ran shite, so I kept upjetting untill it ran reasonably well (by this time I was running a 105 jet in a 50 LOL)... Then once I realised my mistake I dropped the roller weight and downjetted to around 80 and it was mint.

    Too heavy rollers will make your engine bog, which makes people think its the carb when its infact the transmission setup causing the problem.
     
    bertie, Jan 14, 2011
    #22
  3. m1ck_t

    m1ck_t Moderator Staff Member

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    alot of shit
    i meant free for members to use
     
    m1ck_t, Jan 14, 2011
    #23
  4. jay88

    jay88 Member

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    ok mate cheers i have an 82 main jet i can try then i will work from there cheers
     
    jay88, Jan 14, 2011
    #24
  5. jay88

    jay88 Member

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    65
    ive tryed a 82 main jet today and it bogs out at full throttle realy bad it trys to cut out so i put a 98 in it its still a bit boggy but when i let the revs off it feels like it will pick up speed better now im lost i dont no what jet to put init lol any replys welcome cheers

    heres some pics of my spark plug if this helps with a 98 main jet

    [​IMG]

    [​IMG]

    [​IMG]

    and this is my filter if this helps

    [​IMG]
     
    jay88, Jan 16, 2011
    #25
  6. jay88

    jay88 Member

    Messages:
    65
    anyone ??
     
    jay88, Jan 18, 2011
    #26
  7. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    14,276
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    et2 monster
    i really shouldent waste my time as im just typing out whats already in the guide your ignoring...

    the plug looks lean, but thats not to say it is... put a big jet in it... it should still run full throttle but as you come a little OFF full throttle (so at 7/8ths throttle say) if it gets faster as you let off a little then drop a jet... do this untill it is fastest at full throttle.... if you suspect its lean then bash the biggest jet in it and then work with the above advice.. chances are its not JUST the jet tho... try some new 12.5g rollers while you have the thing in bits. wont hurt.

    if you are by your own admission "fucking clueless with carbs and this sort of thig" then WHY are you messing with them? i mean frankly if the bike was running with an airbox and you know nothing about carbs, why would you run the risk of killing the engine for the sake of a filter that will only drop your performance on a 125?
     
    MiNoR cOnFuSiOn, Feb 6, 2011
    #27
  8. lshigham

    lshigham Member

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    250
    Actually, 115 with the 17.5mm is about right. Possibly even too small, they really hate open filters.
     
    lshigham, Feb 9, 2011
    #28
  9. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    LOOOOOOOOOOOOOOOOL you done alot of these then have you?

    throwing a fucking huge jet at a bike with transmission problems just hides poor setup. if a 115 jet is small in a 17.5 i dont know what big is. try changing the rollers on the next bike you "setup" LMAO
     
    MiNoR cOnFuSiOn, Feb 18, 2011
    #29
  10. lshigham

    lshigham Member

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    250
    Who said my bike has transmission problems? You don't even know what bike I have, or how it's setup. As for what big is, try 135. Yes, that's right, 135. When I put the standard air box back on it needed an 80.

    Obviously, I don't have a fucking clue what I'm doing. I mean look at the pile of shit that I built myself

    [​IMG]
     
    lshigham, Feb 21, 2011
    #30
  11. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    with a pwk carb.....


    dont get lemon. your trying to help, but obviously misunderstanding the question.. your bike has a totally different carb to the one in question. keihin jet sizes are WAY bigger naturally. so your 120 ish would be a close guess, if we were talking pwk carbs. were not tho unfortunatly, so the above is just poor advice. dont take things so personally. the "assumption" of mine was based on 99% of scooter owners, who throw a stupidly klarge size jet into a tiny carb to cure transmission problems (usually too heavy) ive sen a million kiddy's throw a million huge jets at carbs and yes it makes them run, but its far from correct. i can but apologise for me assuming you were one of the above metioned kiddy's, but you saying "a 120 is kinda small i recon" with what were actially talking about has simply branded you as the above.

    dell jets are NOT the same as keihin jets... as for throwing up your dyno printout and having a rant, try reading the rest of the post first. ive heard about your bike and sen the dyno graph befor, its real good power for the fact you havent touched the case, its a stock crank and is siomply bolt on parts.. its a bit irelevent to this thread tho.

    as for your dyno, your transmission is HUGELY wrong. look at the graph yourself.. so my assumption wasent really that incorrect now was it?


    can everybody get back on topic now please?
     
    MiNoR cOnFuSiOn, Feb 21, 2011
    #31
  12. lshigham

    lshigham Member

    Messages:
    250
    I was talking about the stock 17.5mm delly and a mild 70 kit and pipe. It needed a 125 jet to even run WOT and a 135 to get the mixture right. I swapped in a 21mm delly and went back to the land of reason, a 92 main on the dyno.

    It would be a complete waste of time posting up the jets a Keihin needed, as the numbering system is completely different and the venturi significantly bigger.

    Yes, I know that transmission was off. We didn't have time to do a run after adjustments, I've dropped some off the rollers now.
     
    lshigham, Feb 22, 2011
    #32
  13. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    well, 120 jet is totally wrong in ANY 17.5.... next time, if you throw more than a 100 jet in a piaggio engine wiht a 17.5 drop the roller weight.. it is WAY too rich, ive set thousands of these up fella, thas just silly huge
     
    MiNoR cOnFuSiOn, Feb 22, 2011
    #33
  14. lshigham

    lshigham Member

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    250
    Yes, I thought that too. Dropped the roller weight so low it was revving it's little balls off, still ridiculous jetting. Even cleaned the carb 3 times thinking something was plugged, nope :confused:cratch:
     
    lshigham, Feb 22, 2011
    #34
  15. MiNoR cOnFuSiOn

    MiNoR cOnFuSiOn Administrator Staff Member

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    et2 monster
    well, your diagnosis of lean was wrong, or you had an air leek. NO 17.5 on ANY 70 even the rich running aerox will EVER need more than a 90 jet, even then its silly big. my old airsal t6 (pritty similar to your s7r) with a yasuni on the stock carb needed a 66 jet. not telling me you needed more than double this
     
    MiNoR cOnFuSiOn, Feb 23, 2011
    #35
  16. lshigham

    lshigham Member

    Messages:
    250
    I reckoned something was up the creak in the carb, swapped for a different one and everything became normal again. It's purely academic now, as I have neither the carb or cylinder kit.
     
    lshigham, Feb 23, 2011
    #36
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