Carb set-up

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greengoblin
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Carb set-up

Post by greengoblin »

Last run of the year today and the bike was running like a bag of s*@t :smt013

Biggest flat spot imaginable between 3 and 4 thou then like a pulsing effect higher up the range :smt017

Thing is , the bikes got a dynojet kit and I just can't get it set up right, at the mo its got the circlip set on the second top notch of the needles and its got 92 main jets.

Does anyone on here have a dynojet kit , and if so , what set-up do you run on.

Also, would old spark plugs have any bearing on this ?
zimm
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Post by zimm »

no idea what setting my needles are on, but im running 105 mains in my dynojetted carbs with a KnN filter and the snorkel removed from the airbox.

you could try it with the stock needles and jets in, see if that fixes it, or changes the symptoms at least.

wouldn't have thought it was the plugs but it couldnt hurt to whip them out and clean them up.

was it running ok before or is this the first run with these settings ?
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greengoblin
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Post by greengoblin »

Truth is it just hasn't ever been that happy running with the kit at all......

Done some more adjustments with the pilot air screw and balanced the carbs but it still runs too lean at the top of the rev range, problem is if I drop the needle down a notch it becomes too rich throughout the full range almost unrideable down low..... don't know if the pilot air screw would sort that or not :smt017

I feel like I'm almost there, just needs more fettling....
zimm
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Post by zimm »

if its too lean at the top, (and rich everywhere else if you raise the needles) id say you need bigger mains, the pilots dont affect anything over about 3k rpm and 1/8th throttle, likewise balancing will only cause/remove secondary vibes in the midrange,

do you have any bigger jets kicking about ?

mine had dynojet #90 mains and was WAY lean even with a clogged stock airfilter, chucked some keihin #105s (stock type, for a given number DJ jets flow more fuel than keihin/stock) in, KnN and took the snorkel out (it obstructs airflow to the KnN which only breathes through its sides unlike the stock filter) and its now "maybe" a tad rich, but not by much, #102/103 probably perfect..

get your mains sorted first, then needles, then concentrate on balancing, and idle mix last.

are you running a stock air filter/airbox ?

you say that if you drop the needle down a notch, it goes rich.. dropping the needles weakens the mixture, assume you mean raising the needle/dropping the clip to third from top ??
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greengoblin
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Post by greengoblin »

Been called back offshore for the time being but will try bigger mains when I get back. Was only going to go to 100's but may be bold as you suggest .

Running with the stock air filter and snorkel at the mo, but would like to try it with a K+N with no snorkel too.

Your right about my terminology RE dropping the needle down... I did mean dropping the clip , sorry :smt003
zimm
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Post by zimm »

if running stock airbox etc , #100's should do it.

what jets come in the dynojet kit ? do they give you alternatives ?

i bought some second-hand carbs which were already kitted so have no idea what actually comes in the kit itself..
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greengoblin
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Post by greengoblin »

Don't know what came in the kit now, it was bought a long time ago and pieces have been mislaid in a house move :smt009

I have two #100's in a box though and it would be no bother to get 2 more, so probably try this first before removing the filter and other bits.....
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