Brand New 450r Cutting Out When Fist Giving It Gas

[03'400exrider]

I bought a new 2007 450r (it's a new 2007- they changed the carb half way through the 07's)They day I brought this home ) which was about 3 weeks ago, it cut out when you first "gassed it". I thougt I would modify it a bit at see if it helped. I put a HMF slip-on exhaust, and a K&N air filter and re-jetted the bike. The same thing still happened. When I give it much throttle very fast, it dies, you have to "feather" the throttle in oder for it not to cut out. I brought it to a performance shop and told them to fix it and have it DYNO-TUNED. They installed another $100 piece called a "HOT SHOT", made by boysen. When I went to pick up the bike, it still done the same thing. They told me there's no way to get that fixed, "that's just part of it, your bike has a race carb", they told me.....but I think it will end up killing me....going up a hill and gassing it, it will cut out for a sec then come to life. Its about to get me or someone else hurt...
This thing has alrady dollared me to death.
Has anyone else ever had, heard of this problem, or know how to fox it? Please help.

[schulte_85]

FCR carbs have a slight bog. You just need to learn to get used to it. You have to feather the throttle at first and then you can stab it. It sounds like you have done everything u can, unless your jetting is off. Also try the HRC Needle. Pilot jet? etc.

[Scro]

Normally the only time the bog is noticed is when you are revving it while sitting still. Mine does it, but I never notice it when I'm riding.

[03'400exrider]

After getting quite disturbed, I brought it to the performance shop. I told them not to call me until it was competely fixed. They change the pilot from a 42 to a 48 and the main from a 120 to a 178.

It is much worse when at an idol but my main concern is the four-wheeler rodeos. I mainly only race in the rodeos. One of the many problems is going to be the pole weave....i just dont think there should be as much as a bog as there is. It is like going and buying a new car, but the cars tires go flat if you turn left. Granted, you can always turn right to essentialy get left, you shouldnt have to.

Im about $8,000 into this bike and dissappointed. I just know that someone has fixed this problem for instance, Can I put a different carb on the bike to fix it?

[Lonestar_R]

Its your leak jet causing the bog. mine had this until I went from the 70 that is in it stock to a 42......its in bowl and is part of the a/p circuit......I would do this it will get rid of the bog and you don't need the Quick shot...that is a waste of 80 bucks

[mike nash]

#35 leak jet is your fix it is the smallest one available. It's the only thing that helped.It's where Lonestar_R said ^^^.

yeppers, a smaller leak jet will cure the bog...a 42 is nearly perfect

[450ERRRRRR!]

I have tried the 45 and 48 pilot jet and found both way to rich and the stock 42 about perfect. Is the air box lid off? IF not take it off. I'm running a 170 main, a crf450 needle and stock pilot with no bog's misfires or hesations. I can punch the throttle and look out!
I think your bog at idle is from to rich on the pilot go back to stock and see. You dont even need to take the carb off, just loosen the clamps , twist the carb, take the bowl off and replace the jet. Dont take it to a shop, learn to do it your self and if you mess it up then take it in.

[03'400exrider]

When you say "leak jet", do you mean pilot? or what?..im most familiar with the banshee and have never heard of the term leak jet. I do most everything myself, its just that this whole bog thing i cannot fix. That is when i brought it to the shop. They charged me $250 just to tell me that they cannot fix it. I was soooo happy..NOT!....but thanks to everyone for the info. If anyhow else has any input, please do so. Thanks

the leak jet is totally different than the pilot jet... it is number 29 in this diagram. and it screws into the hole where part number 52(an oring) is...the list does not have a descriptin for part number 29, but there is a part number 29 in the diagram...that is your leak jet
http://www.sudco.com/fcrmx.html

[slick7108514]

i had this EXACT same problem the day i bought my bike. i brought the bike back to the dealer and they did a complete carb clean and it really really helped it. my bike wouldnt even go past half throttle without dying. now my bike has a slight hiccup when i jab the throttle in like first gear, but its nothing too horrible.

[GPracer2500]

http://img238.imageshack.us/img238/2921/attachmentry2.jpg

The HRC kit swaps the stock 70 to a 55. Some choose to go even smaller. Leak jets work opposite all other jets--smaller is richer, bigger is leaner. They are also known as Accelerator Pump Bypass Jets.