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More top end? Hot Cams, Exhuast, Gearing, Other? 2011

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Really lovin my 2011 kx250f, but looking for a little more top end/gears to pull a little longer/better over rev. What would be my best option? Exhuast? Gearing? Hot Cams Stage 2 (friend reccomended) Something Else? (I have no knowledge of any engine mods or what they do) Not looking to spend to much either

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The stg2 Hotcams will give you the top end rev you're looking for but you'll lose some grunt from the bottom. I'm running stg1 intake cam and a stg2 exhaust cam for the best of both worlds but mine bike is ported and has a 270BB kit on it but I'm not sure how well that combo would run in a stock bike.

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thanks, ive been looking at a few dynos for stage 2 and im not sure if im willing to drop that much bottom for just a tiny bit of top. I saw another dyno with a yosh rs4 slip on and it seems more impressive in gains/less loss of power down low

here is the hot cams dynos I am refering to

http://i746.photobucket.com/albums/xx105/ossafreak/dyno.jpg

here is the yosh rs-4 dynos

http://www.yoshimura-rd.com/images/product/medium/4432_5_.jpg

Trying to find dyno's for other cam companies, maybe race ingniton.

Anyways can anyone help me out with a list of what order to put in engine mods? What is the starting point in looking for improvement, then whats the next add on I can try in additon to the first and so on.. I do not want to buy something that needs three other things for it to work. Im looking to start as small and cheap as possible and add on from there until I like it

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i have been using yosh pipes for a rew years, have one on my 2010. great pipe. i have stage 1 cams in now pulls great. just picked up stage 2 going to try them soon. first mod is a pipe, second cams, third porting. well first on fi would be a remap builders are saying there getting 1hp from it. then the rest.

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you start throwin them mods on your bike the thing is gonna blow up. That 2011 is a rocket ship for a 250 f. Put new clutch fibers in every 10 hours and make sure your clutch basket has no grooves in it and rip. Just an opinion. I have seen people put in that aftermarket crap on 250fs and the bikes turn into scrap metal. You wanna ride or look at a blown up piece of crap in your garage. hey its your bike, you roll the dice if you want, but I have ridden them all, including 450s, and you can beat every bike the way it is. the 2011 is fast. and from what I hear so is the 2009-10

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so what your saying is if he ports his motor and gets a pipe his bike will blow up and turn into scrap metal.

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so what your saying is if he ports his motor and gets a pipe his bike will blow up and turn into scrap metal.

No, but his opinion is smart. Once you start messing with extreme cam profiles, even higher compression ratio's, and other internal mods YOU WILL lose reliability. No doubt about it. The 250F motor is already highly strung out stock, add all those mods and you are asking for it unless you've got a full time mechanic rebuilding your engine every other week. I'm not saying, nor is fshum, that a port & polish and exhaust will blow up your bike but you simply can't expect a 250F to rip like a 450. The Kawi 250F is the fastest production japanese 250F. The most effective, reliable, and cheapest way to make your bike quicker is to perfect your jetting or mess with different fuel maps on the EFI bikes.

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No, but his opinion is smart. Once you start messing with extreme cam profiles, even higher compression ratio's, and other internal mods YOU WILL lose reliability. No doubt about it. The 250F motor is already highly strung out stock, add all those mods and you are asking for it unless you've got a full time mechanic rebuilding your engine every other week. I'm not saying, nor is fshum, that a port & polish and exhaust will blow up your bike but you simply can't expect a 250F to rip like a 450. The Kawi 250F is the fastest production japanese 250F. The most effective, reliable, and cheapest way to make your bike quicker is to perfect your jetting or mess with different fuel maps on the EFI bikes.

Thanks. I did have an 05 rmz with a port job from an experienced engineer, RRP in NJ, and that thing ran nice, real nice. and a pipe too, back and forth with the stock, however. That open pipe was loud as heck, but that bike ran. suspension done by rrp too, that thing was great. I could go faster on that than any 450 basically because 450s are too much for anyone as far as im concerned, and I am, lets say a fairly experienced rider, Im almost 30. all 450's do is get me hurt, that is why I went to the kx250f.

But that's just me. You can ride a 450 great for months, than that one bad day you are having, that thing can bite you when you least expect it.

All im saying is be careful throwing that aftermarket stuff in your sensitive

250f. That thing was designed to run with the parts it had in it. Just be careful with that stuff. Its your bike I don't care what you do with it, just trying to save somebody pain that I have seen others go through. I don't want to knock all aftermarket stuff either, just be careful. and no, a port job from a highly experienced engine tuner (not some back yard bruce, no offense to anyone named bruce) will probably be more beneficial to your engine, and from what I understand, increase reliablility, not hinder it.

I was just reading a post in the yz 250 2 smoke forum the other night, and some guy put up a post about how he got hurt on that bike and how dangerous they could be. Don't be fooled, them things can be as dangerous as a 450. I sometimes catch myself trying to talk me into one of them 2 smokes, then that post made remember the dangers of those too. MX, get some rest and stay in shape and eat well.

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i was being sarcastic if you couldnt tell. no one mentioned agressive cams or hi comp pistons. i run the mods i talk about and only had one problem in 4 years a CP piston pin oveled out the piston got it in time and no damage. and buy the way i have seen a bad batch of stock pistons in 07 and 09. i use vertex now. rossini is still around havent seen him almost 20 years. i rode a new 2012 kxf 250 monday very easy bike to ride thay got the suspension down on that bike but signs off on tha top fast i would be looking into cams and a pipe for that bike.

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FYI - Never use a suppliers dyno sheet. They are always suspect. You need to see a independent comparison by a unbiased engine builder like Eddie or Ron. That Yosh sheet had a extremely suspect dip in the low revs that is more akin to the operator letting off the throttle for a second. You also do not know what the jetting was and more importantly, what the A/F ratio was. For example, the stock run could of been too lean or rich and the second, the jetting made perfect. I see this sort of shenanigans regularly.

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