2013 250 SX-F Consistently Pops on Decel

Does anyone have a new 2013 250 SX-F and notice much popping on deceleration? My son is at the track right now, called me and said it's popping on decel almost like on his old carbed bikes when they were jetted too lean on the pilot. It's 73 degrees there at the altitude is 3,650. The bike just turned over 2 hours and we have not done anything to it yet but change the oil and clean the air filter. Anyone replace the stock map switch yet with the more aggressive one?

Thanks!

My friend had the same thing, check the inline fuel filter and then the filter insdie the gas tank for the fuel pump!!!

I already replaced the tiny inline fuel filter after the 1st 1.5 hours just to see if it would clear up the slight blubbering and it did stop that. But now there is decel popping. This is weird because I bought the bike in the crate, took the gas tank off before ever starting the bike, flushed out the pint of pre-mix looking greenish blue colored fuel that was in there from the factory and put fresh fuel in before we started it for the first time. Are these guys drinking beer at lunchtime there in Austria :cheers: before slapping these bikes together? I spoke with the main service manager at the dealer where we purchased the bike from and he said basically nothing he could do. My hunch is the mapping is off and the bike is running leaner than it should. He said there is no adjustment for the stock mapping. So now I am thinking that we may need to purchase the replacement map plug that has 3 settings. We did that on the 2011 model, went with the aggressive setting and an FMF ti system and it ran great.

dont bother with the plug as all it changes is ignition timing, you need to diagnose the mapping for both fuel and timing etc etc etc

i had this issue and flameouts when I big bored my my 2011 350 with the ht 400 kit, you should take the bike to an efi tuner, and ideally one that has a dyno, run the bike and diagnose mapping then adjust, To get my 350 (400) mapped right it took a couple of goes to get it right (as it was way way lean)

Edited by cd01

dont bother with the plug as all it changes is ignition timing, you need to diagnose the mapping for both fuel and timing etc etc etc

i had this issue and flameouts when I big bored my my 2011 350 with the ht 400 kit, you should take the bike to an efi tuner, and ideally one that has a dyno, run the bike and diagnose mapping then adjust, To get my 350 (400) mapped right it took a couple of goes to get it right (as it was way way lean)

Thank you, will do as this makes sense. KTM went too lean on the fuel mapping for the 2013. I guess if I put an aftermarket full exhaust system on it will run even leaner and pop even worse on decel!

Thats what I forgot to say, if you have an after market exhaust you need to get it diagnosed with that as the myth that the bike "will self adjust" with the pipe is exactly that a myth !!!!

On my 350 (400) I had a full fmf ti megabomb system and yeah like I said the tuner could not believe how lean it was running !!!!

good luck mate :ride:

Yea as we've talked about in the other thread, the ignition map switch doesn't do much. It does make a noticeable difference, but it doesn't get rid of it. My opinion is a lean condition at 5% throttle input. If you stay on the throttle entering the corners, it doesn't happen. That tells me, its for sure related to mapping.

Re-mapping the bike seems to be the only true solution as the bike doesn't have an 02 sensor, so it can't "automatically" adjust for anything.

I'd like to find someone with a dyno and get a REAL nice map made.

Edited by tye1138

The decel pop was very evident when I rode the 250sx-f at the KTM demo day at Redbud as well (and clearly heard in the video). I chalked it up to it being a demo, sounds like its an issue with the model.

Im telling you right now its the filters on the fuel pump, both 13's were clogged!

Im telling you right now its the filters on the fuel pump, both 13's were clogged!

Clogged fuel filters, degrade the fuel pressure of the system. The more the filters are clogged, the less pressure the system outputs.

This means, the bike would have issues accelerating, it would buck and/or when revving the motor, you'd feel it being jerky.

The deceleration issue is caused by a poor fueling map when the TPS is at 5%. This is why when you close the throttle fully, it pops and when you don't close it fully, it doesn't pop. Advancing the ignition slightly, helps resolve the issue, this is why MXA discovered the map switch solves some of these pops. I agree with them, it does solve MOST of them.

If it were a fuel supply issue like a bad filter, the map switch wouldn't do anything. ;)

Well whatever you said im sure is right but all I know is after we swapped out the fuel filters inside the tank it didnt do it anymore. So take it for what its worth. P.s tye im coming down in 2 weeks for 5 weeks. Lets go ridin!! Pm me ur #, ill be riding 5 days a week during the day

Well whatever you said im sure is right but all I know is after we swapped out the fuel filters inside the tank it didnt do it anymore.

It may be a filter, but all logic points to a bad map. I've been down this road SOOOO many times, I use to service Ducati's and I have a lot of experience diagnosing issues like this and its always just mapping or ignition timing. Sometimes, just shifting around hoses in the fuel tank, can help release stress in the system which could cause a lean condition. I'm OK with that premise, but to say the filter is bad on a bike which is a few months old and doesn't have any other symptoms? EEK!!! hard one to diagnose! Maybe I'll pop my tank apart and see what the filter looks like, might as well! ;)

They are silly expensive for what they are

I've got the older 250sxf so maybe it doesn't apply, but the way KTM mounts the header, it leaks causing popping. I use that white exhaust pipe sealer from the auto parts store and it greatly reduces popping for at least a ride or two...

After calling two KTM dealers yesterday to inquire about getting the fuel mapping adjusted to go a little richer I found out that this lean setting on the 2013's was intentional due to new emissions regulations. Wonderful!! So one of the two dealers service dept managers said he could not do anything to richen the fuel mapping a tad, just live with it, and the 2nd dealer recommended purchasing/installing the JD Fuel mapping kit ($209.95). I called the Southern Calif Dealer Support Representative this morning and asked for his advice on this lean issue.He said he will have an answer back to me by COB today. I'll report back later or tomorrow with hopefully some helpful advice for all of us loyal KTM customers.

Just out of curiosity if any of you reading this are outside of California and especially if you are outside of the US, please comment if you are having the same decel popping over there with the EU version. Something tells me that we in Calif. may have models that are tuned leaner to meet EPA/CARB rules. This would not surprise me.

Edited by MDSmith

I've talked with KTM about different maps. According to the tech guys there is only one map available for the 13 bikes and as far as they knew there will be no alternative maps. Supposedly this map has been tested with aftermarket pipes and it's OK to use any of them with stock mapping.

I guess the TPS voltage could be off a little bit. I've messed with several with fuel delivery problems and they all had acceleration issues as well, your problem sounds different though.

Looks like u need to turn red button to add more rev when throttle is off. I´ve done it 2-3 times. It helps also with throttle response. Before, when U hit the throttle fast the bike think for a second before revving.. after doing it the bike revs immediately. U can try it.. It solved my problem.

Right red button.

kk350engine.jpg

Edited by Tan313

find some one with the ktm map tool and some knowledge of tuning efi. my buddy has the tool and knowledge he did my 12 250sxf after i put the fmf ti megabomb on. it was a day and night difference. remapping/ moddifing the map got read of any bog i had and no decel pop. plus the bike will have a little more power do to a improved air/fuel ratio rates so your not getting more or less fuel you need your getting the correct amount.

I´ve owned 2007, 2009, 2011, 2012, 2013 all 250sx-f and all but 2007 were new. Never had any issue with decel popping. Done about 150h with every one of them. With 2013 250sx-f Ive been riding about 35h and havent had any issue besides the revs were too low when throttle was off (it happened after 5h of riding). After fixing this everything is fine.

I also removed flame catcher from stock exhaust and Im using 250SX 2stroke filter cage. That helped with throttle respond. Use 13/51 gearing and this machine is competetive as it is :)

Do these steps before u start remapping :)

Does anyone have a new 2013 250 SX-F and notice much popping on deceleration? My son is at the track right now, called me and said it's popping on decel almost like on his old carbed bikes when they were jetted too lean on the pilot. It's 73 degrees there at the altitude is 3,650. The bike just turned over 2 hours and we have not done anything to it yet but change the oil and clean the air filter. Anyone replace the stock map switch yet with the more aggressive one?

Thanks!

How did you fix this? I have tried everything except for ecu changes.

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