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Discussion Starter · #1 ·
well we tried the bike out yesterday and it still is missing bad..also we switched bac to stock ign and its doing the same as the msd ign so what do you guys think is the problem?..its when you put a load on the bike and launch from dead stop but when you get it going on topend it runs pretty good is the weird part so any help would be appreciated..we are thinking maybe the stator or coil..
 

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sounds like the same thing i was fighting on my yfz. i changed stators, carb, wiring harness, cdi, ect. ended up being a problem with the head. I havent torn the head apart yet, but im guessing its a broken or weak spring. May be something to check on the raptor. but try the easy stuff 1st.
 

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Discussion Starter · #6 ·
QUOTE (dylan @ Jun 28 2009, 06:59 PM) index.php?act=findpost&pid=48451sounds like the same thing i was fighting on my yfz. i changed stators, carb, wiring harness, cdi, ect. ended up being a problem with the head. I havent torn the head apart yet, but im guessing its a broken or weak spring. May be something to check on the raptor. but try the easy stuff 1st.

i hope its something simple and not trhe head that would suck major..but yours breaks up when u launch?..the weird part though is last week w/stock ign it ran great the bike was just fat..
 

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mine would run fine with stock tires with no traction, but as soon as i would get it on the track under a load it would start missing. once i would get to top end it would clear up. but when i'd shift from 3rd to 4th it would miss again until i got to the top of the gear. its hard to explain, but i fought the problem for about 2months and ended up rebuilding that motor with a different head and problem went away. Im not saying this is your problem, just throwing it out there.
 

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I think it sounds a lot like jetting too. Most bikes are the exact opposite of a banshee. They sputter a time or two under a load off the line when rich then clear up. My bet is its hotter out now than when it ran ok so its richer now.
 

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Discussion Starter · #12 ·
QUOTE (dylan @ Jun 28 2009, 08:18 PM) index.php?act=findpost&pid=48458mine would run fine with stock tires with no traction, but as soon as i would get it on the track under a load it would start missing. once i would get to top end it would clear up. but when i'd shift from 3rd to 4th it would miss again until i got to the top of the gear. its hard to explain, but i fought the problem for about 2months and ended up rebuilding that motor with a different head and problem went away. Im not saying this is your problem, just throwing it out there.

wow this right here is scaring the crap out of me...you are describing the same symptoms mine is doing..matter a fact when i launched here at the house on pavement it done great with 4snows but we put a set of 14 ext and it started acting up..
 

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QUOTE (tripledsracing @ Jun 29 2009, 05:05 PM) index.php?act=findpost&pid=48557wow this right here is scaring the crap out of me...you are describing the same symptoms mine is doing..matter a fact when i launched here at the house on pavement it done great with 4snows but we put a set of 14 ext and it started acting up..

Mine's started doing something like this too, weird. Switched out needles and it ran fine on teh pavement then took it to the river with some paddles on and back to teh same 'ol bog issue. Gonna try some different jets to see if that helps out.
 

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Discussion Starter · #14 ·
QUOTE (okbeast @ Jun 29 2009, 03:21 PM) index.php?act=findpost&pid=48559Mine's started doing something like this too, weird. Switched out needles and it ran fine on teh pavement then took it to the river with some paddles on and back to teh same 'ol bog issue. Gonna try some different jets to see if that helps out.


hmm id say your might be gearing or to fat..which im hoping thats my problem because the nitro needle in it the depth of the cut in the needle is very,very deep and it doesnt taper hardly any looks like it stays the same so hopefully this will cure the problem..
 

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If your running the needle that ubetrun or whoever ran 40% nitro with, then that's somewhat like trying to run gas in a carb with an alky needle. It's gonna be quite a bit too rich.
 

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Discussion Starter · #16 ·
QUOTE (Radar @ Jun 29 2009, 07:37 PM) index.php?act=findpost&pid=48601If your running the needle that ubetrun or whoever ran 40% nitro with, then that's somewhat like trying to run gas in a carb with an alky needle. It's gonna be quite a bit too rich.

im not running the 40% needle its the 20% needle which im gonna get me a different needle and hope that solves the prob..
 

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Ya I'm hoping it's just too fat too. I hate going leaner, need some time to do some plug chops I guess to figure it out. I sure hope it's not gearing I would hope a 421 cub could pull 14/41 but maybe she's wore slap out.
 

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Discussion Starter · #20 ·
called packard he said the pe-5 needle should work if its not been cut anymore for nitro...also there is another bike almost identical to mine and he only runs a 48mm carb and it runs great maybe the 52mm carb is way to big..also checked the cap on coil and it seemed a lil loose so i fixed that hopefully that was the problem..anyway anyone have any more info lmk
 
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