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running a bit lean

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Is there any quick/simple solution the richen up the bike a bit,my 2014 kx450 seems to run a bit lean on the standard and aggressive couplers but the mild one seems fine.If I could richen it up some would help a lot.I went to the dealer to see if they could reprogram the ECU but they told me I would have to buy a new reprogrammed one instead.I know there are modules that can do it for me but that would cost in the hundreds of dollars,i'm just hoping for a simple solution to give it a bit more fuel I don't want in depth reprogramming as the power on it is fine.

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Is there any quick/simple solution the richen up the bike a bit,my 2014 kx450 seems to run a bit lean on the standard and aggressive couplers but the mild one seems fine.If I could richen it up some would help a lot.I went to the dealer to see if they could reprogram the ECU but they told me I would have to buy a new reprogrammed one instead.I know there are modules that can do it for me but that would cost in the hundreds of dollars,i'm just hoping for a simple solution to give it a bit more fuel I don't want in depth reprogramming as the power on it is fine.

No, there's no quick answer except for checking your bike for air leaks. The dealer is right, it has to be reprogrammed. That being said, whats going on? Popping on decel?

My bike did the same thing and still does every once in awhile, but nothing to be too concerned about. It actually got better with a pipe tho.

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popping while under low load at 1/4 throttle or below,if I'm cruising on a trail at low speed the bike is constantly popping out the exhaust.Popping on decal I can live with and know its somewhat normal,I noticed it the very first ride with the standard coupling in,went to the black thinking it was the aggressive and it was much better but then found out that the black is the mild setting.I know if I put the white coupling in it will pop bad,once your past that 1/4 throttle range it works fine.Only thing that comes to mind that could be a problem is the air filter,I haven't checked it from when I bought it as I only ridden it a couple times but it may not have been oiled,is this some the factory or dealer doesn't do?I will check it before I take her out again.

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Did it always do this?

 

If not, something else is going on, either way, under load is a different story.

 

I doubt it's the ECU, sounds more like a sensor issue or something else.

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Did it always do this?

 

If not, something else is going on, either way, under load is a different story.

 

I doubt it's the ECU, sounds more like a sensor issue or something else.

brand new bike just ran long enough to break in and change the oil.

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Maybe the filter is oiled to the max?

 

I would have taken that thing right back to the shop had them look at it, that's not right for a brand new bike.

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gona check the filter tomorrow but I think its a mapping issue along with the colder air here as the soft map its almost gone.If the filter was oiled too much wouldn't that effectively give it less air and make it richer?I'm not familiar with FI on these bikes,in a car the o2 sensor lets it adjust the air/fuel ratio but I don't see an o2 sensor on these bikes so I'm guessing its a fixed setting and if the bikes are meant to be run in warmer climate then up here its not gona be the same.Maybe later in the summer it will run better.What do ppl do if they wan to run these bikes at high altitude,at least with a carb bike you can swap out the jets.

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My bike does the same thing. Always has since it was new. Even with the rich coupler in, it still gets that partial throttle/ low load backfiring all the time

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Not really on acceleration, but let's say I'm riding from the pits to the track at 1/4 throttle, my bike will keep back firing. It's don't it since new. And it also likes to backfire on decel

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Not really on acceleration, but let's say I'm riding from the pits to the track at 1/4 throttle, my bike will keep back firing. It's don't it since new. And it also likes to backfire on decel

exactly what I was trying to describe.What coupling do you use?

Edited by etuke

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I mostly use the green one, sometimes I use the black one too. I never use the white coupler

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Is there any quick/simple solution the richen up the bike a bit,my 2014 kx450 seems to run a bit lean on the standard and aggressive couplers but the mild one seems fine.If I could richen it up some would help a lot.I went to the dealer to see if they could reprogram the ECU but they told me I would have to buy a new reprogrammed one instead.I know there are modules that can do it for me but that would cost in the hundreds of dollars,i'm just hoping for a simple solution to give it a bit more fuel I don't want in depth reprogramming as the power on it is fine.

Hey bud go on the Suzuki threads there's a guy by the name BDubb he can hook you up with a guy who revamps

for 50 dollars. He's good guy.

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Had a good ride today and took all the couplings with me to try,weather was warm and I headed to the sand pit.I tried the white and it didn't impress me at all but there wasn't much popping at all.Went to the green and it seemed good lil to no popping so I went back to the black and ran it some.Ater trying all the couplings I ended with the green,it seem to suit my riding style with plenty of power.I didn't find the white more powerful even down low in fact it seemed lacking and I ran it on hard pack and sand.I don't know why first when I got it the popping was there but now it seems fine,maybe needed breaking in or warmer weather.So far I'm quite happy with the bike,the suspension is soft but still handles the jumps,power everywhere,nice slim feeling to the bike.Couple things I done like but will get used to are the nose dive under braking and the twitchy throttle at the beginning that reminds me of my 2 stroke.

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I was thinking that. But I wasn't sure if it's an EFI thing or the throttle. I'm actually using a procircuit throttle tube since I broke my stock one when I tipped over in corner.

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If it's cold weather where you're at, that could be the issue with the popping. Cold weather equals more fuel needed and the mapping and sensors probably were not making up for it. Glad you got it figured out.

 

The suspension overall is great, but these forks dive like crazy. I just ordered a set of SDI midvalves and I'm going to swap them out this week and see if it fixes it.

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