Looking for a tad more top end.

Firstly the bike is a 2009 KX250F.

So I'm looking for a few tips on how to get my bike a lil more how i want it.

The bike seems to rev out pretty quick, to where I'm needing to shift through gears pretty fast. I know this is how a 250f is, but is there and modifications that can be made to make the bike rev out a little further? It seems to rev out earlier than my buddies 2011.

2nd, whats a good mod to bring a lil more power to the top end? I will sacrifice some bottom end of course but I'm use to riding a 2 stroke so I'm good with losing a lil to gain a lil top end.

I heard getting an oversized carburetor will help with mid to top end power, and i heard that it will also make the bike rev a little farther, all of which i want, but I'm unsure and there isn't much info to back those rumors up....

3rd, and least important, this is more for bling bling, but will the 2013 Kx250f or Kx450f front fender fit my 2009? Just like the looks of the fender and was curious as to if I'd need to drill holes.

The cheapest way would be to swap out the rear sprocket.  engine mods are very $$$$ costly and if you are willing to spend the money on them I suggest researching them and finding out which would give you what you want... or go to a local shop and ask them how to spend the money... if you want them to do the work.

 

I have no experience with the 2nd idea you had... I would just google it tell you don't want to read any more or maybe someone will be able to help here.

 

I have heard these help top end

http://www.motosport.com/dirtbike/Scary-Fast-Power-Now

 

http://www.motosport.com/dirtbike/intake?limit=60   < page is full of ideas.... research them, do the math and see if it is really worth it

 

Several people I ride with have them installed and I had one in my old carb bike and it was noticeable.  

 

 

bling bling... you got money? because you can jump on any online bike store and just click "add to cart" for your year of bike and the aftermarket parts they make for it... for that year you have tons of options.

The cheapest way would be to swap out the rear sprocket. engine mods are very $$$$ costly and if you are willing to spend the money on them I suggest researching them and finding out which would give you what you want... or go to a local shop and ask them how to spend the money... if you want them to do the work.

I have no experience with the 2nd idea you had... I would just google it tell you don't want to read any more or maybe someone will be able to help here.

I have heard these help top end

http://www.motosport.com/dirtbike/Scary-Fast-Power-Now

http://www.motosport.com/dirtbike/intake?limit=60 < page is full of ideas.... research them, do the math and see if it is really worth it

Several people I ride with have them installed and I had one in my old carb bike and it was noticeable.

bling bling... you got money? because you can jump on any online bike store and just click "add to cart" for your year of bike and the aftermarket parts they make for it... for that year you have tons of options.

you nailed it son.. Re gear it.. go down one or two teeth on rear

I've heard mixed feelings on the Scary fast. Put one in my other 250f and didn't notice a difference at all.

With the sprockets i figured I'd get a lot of suggestions to drop a few teeth. I'm running 13/49 right now. Are you thinking 13/48 or 47?

When i got the bike it had a 13/51 and i hated it so much! So i dropped a couple teeth.

Might look in to a more free flowing exhaust and a loudmouth mx intake system. They make air filter changes a breeze also! I've got an FMF megabomb/factory 4.1 setup and a loudmouth mx intake on my bike. My bike is pretty much all top end. I'm running 13/51 also.

 

edit* forgot to mention I also polished my intake ports on my cylinder head

Edited by NthoozEist

I've heard mixed feelings on the Scary fast. Put one in my other 250f and didn't notice a difference at all.

With the sprockets i figured I'd get a lot of suggestions to drop a few teeth. I'm running 13/49 right now. Are you thinking 13/48 or 47?

When i got the bike it had a 13/51 and i hated it so much! So i dropped a couple teeth.

 

 

Sure that is why I suggested getting a couple of cheap sprockets and do a little testing.... No way to know tell you test it out... I can tell you for a fact that it will make a difference to put on a 47... but how much that is all on you and your style of riding... me I run 13/50 and it works, great all around setup, track, woods, name it I ride that and it just works, sure I could drop a tooth here and raise a tooth there but it isn't worth changing the setup and I am not that picky... if you are then you will want to put in the time and do a little testing.

Sure that is why I suggested getting a couple of cheap sprockets and do a little testing.... No way to know tell you test it out... I can tell you for a fact that it will make a difference to put on a 47... but how much that is all on you and your style of riding... me I run 13/50 and it works, great all around setup, track, woods, name it I ride that and it just works, sure I could drop a tooth here and raise a tooth there but it isn't worth changing the setup and I am not that picky... if you are then you will want to put in the time and do a little testing.

Stage 2 cams will move power up top, noticeably move it up top to be truthful. The 13 front fender will work on your 09, you need the cycra # plate or make your own pins for the OEM style 13 plate. Been takled about tons of times.

Okay going to try a 48 rear sprocket order and see what that does, but I'm pretty sure the 47 would be too far, i have a feeling i wouldn't like it.

But i guess I should clarify a bit. I'm referring to overrev. I'm wanting a little more over rev.

You will need to get an aftermarket ECU if you want more over rev, but you loose reliablity by doing that.

 

Stage 2 cams are your best bet with a good exhaust and then jetting to suit.  

Cams, porting, pc exhaust, moto tassarini airforce intake, ignition, spot on jetting.

Making more power isnt a mystery. Its all about your budget.

Sprockets is a cheap, yet good way to go.. But if you really need over rev, then gotta put on your game face and have your $$$$ ready

Cams, porting, pc exhaust, moto tassarini airforce intake, ignition, spot on jetting.

Making more power isnt a mystery. Its all about your budget.

Yea i know its not a mystery, but the search engine on TT is very lacking, and google is no better. So instead of searching "Engine mods for dummy's" or something like that, i figured I'd just ask. So the PC exhaust will boost topend or overall power? I heard most pipes just boost the bottom end mainly. And about cams, would they reduce reliability at all? I'm still delving into the complicated engine of 4 strokes, they're SOOO much more complex than the old 125s....

Hot cams will boost the top.end they dont require stiffer valve springs which is a clue into how radical or not they are and how they will effect reliabbility, i had great luck with dr d exhausts boosting power from bottom to top but pc seems to be more.top end focused and not as broad. Anything that will move the power up top and havr you keeping it signing non stop up high will reduce your engjnes life but good maintenance and some mechanical sympathy goes a long way.

Hot cams will boost the top.end they dont require stiffer valve springs which is a clue into how radical or not they are and how they will effect reliabbility, i had great luck with dr d exhausts boosting power from bottom to top but pc seems to be more.top end focused and not as broad. Anything that will move the power up top and havr you keeping it signing non stop up high will reduce your engjnes life but good maintenance and some mechanical sympathy goes a long way.

So the dr d kinda raises the power throughout and the pro circuit boosts top end only? More to think about...

So far my list is this for in the off season. What do you think?

Boyesen Quickshot 3 accelerator pump

Loudmouth Intake

Pro circuit or Dr.D pipe not sure yet.

I have the same problem on my 2009 kx250f. Currently i have 13/50 sprockets and im gonna try 13/49 to see how that goes. My bike has a. Fmf megabomb into a fmf powercore 4.

I had the same problem when I had a 09 kx250f. my wifes 07 k250f reved further then my 09. jetting didn't fix it. Gearing will make the gears longer but the engine will still hit the wall of a rev limiter! Cam may fix the problem or sell and get a newer bike.

I have the same problem on my 2009 kx250f. Currently i have 13/50 sprockets and im gonna try 13/49 to see how that goes. My bike has a. Fmf megabomb into a fmf powercore 4.

Was there a noticeable difference? I'm just wondering what the difference is when you use a pipe on a 250f I've either ridden them when they already had a pipe, or it was stock, so i couldn't back-to-back compare the difference in them. And i don't really want to jump to mod class if the pipe doesn't do much, since i run amateur nationals in stock class right now.

Was there a noticeable difference? I'm just wondering what the difference is when you use a pipe on a 250f I've either ridden them when they already had a pipe, or it was stock, so i couldn't back-to-back compare the difference in them. And i don't really want to jump to mod class if the pipe doesn't do much, since i run amateur nationals in stock class right now.

pipe has been on there sence i got the bike so couldnt tell you sorry

pipe has been on there sence i got the bike so couldnt tell you sorry

Ah gotcha, no harm done.

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