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2012 kx250f - trying to make it faster (Loud Mouth Intake, Mototassinari Air4orce, Yoshimura Rs-4, ace gas

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A 'B' rider still is no match for a stock bike, by a long shot. The desire for more power on the surface appears to make sense however, the reality is, your skill level will not be able to make much use of it and may actually cause your lap times to go down.

If you try to boost power, you will cause the engine to not last as long. Simple fact. One of the costs of 'go fast'.

If you cannot tune the bike, all the add-ons will do is cause you to loose power. Get a ECU tuner for your lap top. Methodically experiment. Learn how it works and the effects it has on engine behavior. You'd be amazed at what a little ignition timing change can do.Things like race gas is the last thing you do when you are a pro rider. Higher octane fuel makes LESS power then the fuel recommended for your bike. You always want to run the minimum octane you can without detonation. Some race fuel have a high O2 content and give you a touch more power.

Most people who put add-ons on do not actually test. They spent money, the bike is louder and they assume it is more powerful. Or the power delivery becomes choppy and what is perceived as a rush of power is in fact a return of 'stock power' getting out of a flat spot caused by a poorly setup add-on. Dyno your bike stock. Make a change, dyno it again.

I could write a book about this, many others have. Do not buy into the hype of advertising. Practice instead. A great rider on a TTR125 can smoke a mediocre rider on a worked 450. Be a great rider.

All of this knowledge as well as having the skill to ride to make the utmost of the bike are key before you start modding. Understanding this is critical.

You know william, you're a good person but sometimes I think you're speaking from what you were told and don't know it to be correct..

First let me correct you on "RACE"Gas If someone is running race gas you get from your "local" gas-station then by all means you're correct.. How ever most people when they come to the boards and are inquiring about race gas they are not talking about the local 110 wholesale high octane gas.. They are referring to MX oriented Oxygenated race fuel. These bikes have enough compression that running upto 98-103 octane will not loose power and will run a tad bit cooler.. How ever vp u4.4 is 103 octane, oxygenated, and designed for engines running 10:1 to roughly 13.5-14:1 compression ratios. The only down side to using this is that it needs to be a richer fuel setting Not sure how much the 2012 was leaned out compared to the 2011 but the 2011 with stock map should work pretty much perfectly due to its rich fuel settings.

Second. You claim a "B" Rider is no match for a stock bike.. I beg to differ.. This is true in the 450 relm how ever in the 250f relm it is not.. Not in the starting department and definitely not on a track that is loamy or sand.

Third. The OP was not talking about running mods that require extensive work to the motor. I.e. Decking, porting, Higher comp pistons, Cams, etc etc.. He was talking about simple mods that will add just a touch of power with out sacrificing his wallet or his reliability. So your claims on it will make him slower etc etc are just that of someone who is set in his ways and will not believe anything else other then what he has been TOLD.

Fourth: you made claim to a "Great"Rider on a ttr125 can smoke a mediocre rider on a modded 450f.. That is Apples to ORANGES here.. We're talking about 250f's, We're talking about a FRONT PACK B rider, and We're not discussing MAJOR MODS... Only thing I come up with on that passage is just a random tidbit to make it seem that you're right but truly had no value to the conversation at all.. Granted you're an knowledgeable person but please stop with the "holier then tho" mentality. You have some great points don't get me wrong but you're over bearing and seem to speak about "what you may/may not know" at the wrong moments here or at least on the kx250f section.. This thread is one of them. And just about any thread someone mentions "PILOT JET" Thank GOD for EFI soon no one will ask about Pilot Jets!

Now for my response to the OP:

The loud mouth intake isn't going to change anything.. I also do not think it will work with the Airforce as the airforce is the entire airbox and includes it's own intake tract.

the stock exhaust is restrictive and will allow the bike to breath much better and the Yosh seems to be a pretty good pipe. I was planning on getting one till I fell on a deal with another brand I couldn't pass up..

your inquiry into race gas.. As I stated above to William. He is correct if you're planning on running race gas from some gas station.. If you run race gas you need to run an Oxygenated gas MX specific. U4.4, dragon fuels, and there's a few others.

Keep in mind if you go with these solutions you should have someone do a remap on your ECU setup for oxygenated fuel, the exhaust, and intake. How ever I will say this if you practice with pump gas you're going to be running WAY rich if the ecu it setup for oxygenated fuel but will be PRIME when you're running the oxygenated fuel. Keep in mind that you probably wont find any in between if you want to be able to switch fuels.. That's the problem with fuel injection and OXY fuels unlike carbs you can re-jet if you switch. Well I guess you can with an ECU if you the setup to do it..

Now, in retrospect if you go with the airforce, yosh pipe, oxy fuel, and an ECU remap you will add a noticeable gain in throttle response and a more dynamic powerband. How ever.... It's not going to be the "WOW" factor you might think might net you 1 possibly but not likely 2hp gain. It maybe enough it may not be enough to get you through that corner with out needing to downshift..

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pr1mal- Thanks for the response, tons of good info in there.

Since this thread started I have changed my mind so many times I just don't know which route I'm going to go down yet. I am either going to 1. Ride the bike stock for another half year and sell it to get a 450/250 2 stroke. 2. Put the mods on first, if I see the improvement I am looking for then I'll keep the bike for another full year. 3. Ride it stock until it needs motor work and then go full mod. 4. Leave the bike stock and buy a cheap older 250 2 stroke and ride them both. Ill update you guys on a review of any products/mods I end up doing. Thank you everyone for all of your responses

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Err, I never said anything about pump gas.

I talked about the need to remap as it will have a huge effect either stock or with the parts. Without a remap, add-ons will often slow the bike down.

You missed the point about going fast being the rider and not the bike. If it will make you happier, a crappy rider on a worked 250F will be whooped by a great rider on a RM85.

Please do not put words in my mouth. I have no idea what you mean by what I was told. I worked in the industry for years, starting at a dealer and the working for the factory. Please get you facts straight.

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Err, I never said anything about pump gas.

You linked "Race"Gas with the stuff people purchase from Sunoco, KnollBrothers etc. This at 110octane or higher or will not do any good for a bike as you mentioned. I broght in the point of the OP was most likely refering to Oxygenated MX/SX Small engine fuel. And that being designed for these bikes will not loose power rather will gain power with out any mod. Will gain more power using it if you remap the ecu to increase fuel rate.

I talked about the need to remap as it will have a huge effect either stock or with the parts. Without a remap, add-ons will often slow the bike down.

I personaly think you're back tracking. Your first post was it wont work for you and you will never be able to ride a stock bike to its potential even as a Front Pack B rider. as I said before you are knowledgable but you're over bearing and don't ask the right questions to give the right answers.

You missed the point about going fast being the rider and not the bike. If it will make you happier, a crappy rider on a worked 250F will be whooped by a great rider on a RM85.

Well sir that is more of a better scenario for the group.. How ever this still doesn't apply to a front pack B rider that can handle a 250f.. Once again not pertitant to this discussion. Had the "OP" have been a beginner C rider then your point are valid. But He's not so its negated.

Please do not put words in my mouth. I have no idea what you mean by what I was told. I worked in the industry for years, starting at a dealer and the working for the factory. Please get you facts straight.

I'm not putting words in your mouth you're the one who blurted out "you don't need more power practice instead" I'm the one who just looked at the facts and what the OP asked about and saw you're off topic conclusion rather then answering the Ops questions. Had your original post have said.. "Most of the time it's better to save your money and practice more as most people are not able to use the power of a 250f. How ever these mods you listed will do this and that" might have been a tad bit more apropriate then your first response and then your second response trying to back up what you said rather it just made you look like you're "Holier then thou and all must conform to the ultimate wisdom you bestow upon us"

As I said before William, you are very knowledgeable but you Try and Tower over everyone as if no one else is right unless they agree on what you say.. This is how I feel you present your self and I'm not trying to attack you. It's just how I see you most of the time I read your posts. Not that I disagree with what you're saying as you have valid points just most of the time they are not pertinent to the discussion you're posting in. I am also not the only person who thinks the same way. I have had several PMs about you and how they can't stand you. I don't personally dislike you I just feel you're set in "YOUR" ways and there is nothing wrong with that but what I do is I will tell you how I feel and what I think. It's not to attack you its just to say Hey ask the right questions and you will possibly give a lot better answer..

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Not at all. You just resent me for some reason, perhaps because you have been corrected in the past. Not a lot I can do about it. It is up to you to listen to those with experience and then chose to use the knowledge being shared or to ignore it. But to complain, well...

I did not 'link' to anything. I said race gas, plain and simple. I mentioned the only fuel that will give more power would be O2 fuel, that higher octane often results in less power and to run the lowest octane the bike will tolerate.

Higher octane fuel makes LESS power then the fuel recommended for your bike. You always want to run the minimum octane you can without detonation. Some race fuel have a high O2 content and give you a touch more power.[/Quote]

Again, please do not make your own statements and infer I made them.

No, a 'B' rider is still a beginner (albeit a good one) and a long way from a Pro/'A' status. It is pertinent to this discussion as the OP is a 'B' rider and wants to go faster. The OP is not a front of the pack 'B' rider (No offense, OP) based on his own comments. He needs to improve his skills more and worry about the bike less. This is hammered home by his lack of desire to do a remap, which is basic tuning. It is very apparent he needs to practice more.

Your last comment, well it speaks for itself.

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Gotta love the fact you are in denial. Making asumptions the rider is not this or not that and needs not worry about his bike. I love that.. You sir still prove everytime you post ecxactly what I said you're doing. You're trying to insert your self as a PILLER that can't be moved. That and you're trying to say someone is a "beginner" if they don't know anything about there bikes not all people have a clue about what makes there bikes perform better or not and that doesn't mean they are a beginner rider!

Fact:. you don't know this person

Fact: you don't know he isn't a Front pack rider

Fact: Ryan Dungy went from racing "b" Class straight to PRO making you're statement a "B" Rider is a beginner negligable

Fact: LL's 2011 a "b" Rider set the fastest lap times of the entire week. again your statement is now null

Fact: you're making claims based about the OP on opinion rather then FACT

Opinion: everything you said about the OP.

Opinion: you think I resent you

Fact: I don't resent you I just think you're an arrogant person who must push his views on others.

Fact: I also do not need your experience nor have I asked you for it.

Fact: This discussion is now way OFF TOPIC and I'm done with arguing with you.

Edited by Pr1malR8gw

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I apologize to the OP for going off topic in his thread. Sorry.

Primal, show me what I said that was wrong and I'll be more than happy to correct my errors.

Fact:I do not know the OP nor do you as far as I can tell. I am not sure how that matters as all anyone has to go on is what he has posted. Right or wrong.

Fact:The OP stated he is a fron of the pack 'B' rider and did not qualifty for LL.

Fact: If RD was a 'B' rider and went pro, he was sandbagging. Not the first time, not the last. I have no idea why you put this in here

Fact: Statements made are based on the information the OP provided.

Fact: You come across full of resentment. Re-read the thread.

Fact: No you did not, the OP did, it is his thread, not yours or mine. Re-read the thread.

Fact: I was never arguing. I was merely stating facts.

To the OP, I sincerely feel, based on what you have posted, you need to practice. You might benefit from the guidance of a coach or an 'A' riders critque at the track. Get your bike mapped for YOU, mke sure the suspension is truly right. Too many people want to blame the bike. They want to spend 'easy money' on hop up parts that might make them a little faster on a track with long straights. Races are won most often in the corners and approaching the jumps. Think about how fluid your riding it. You should feel like you are always floating on and never fighting the bike. Listen to people who have seen you race and ride. If several people say the same thing, it is probably true (and they are not trying to yank you).

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Not at all. You just resent me for some reason, perhaps because you have been corrected in the past. Not a lot I can do about it. It is up to you to listen to those with experience and then chose to use the knowledge being shared or to ignore it. But to complain, well...

I did not 'link' to anything. I said race gas, plain and simple. I mentioned the only fuel that will give more power would be O2 fuel, that higher octane often results in less power and to run the lowest octane the bike will tolerate.

Again, please do not make your own statements and infer I made them.

No, a 'B' rider is still a beginner (albeit a good one) and a long way from a Pro/'A' status. It is pertinent to this discussion as the OP is a 'B' rider and wants to go faster. The OP is not a front of the pack 'B' rider (No offense, OP) based on his own comments. He needs to improve his skills more and worry about the bike less. This is hammered home by his lack of desire to do a remap, which is basic tuning. It is very apparent he needs to practice more.

Your last comment, well it speaks for itself.

the second post by the OP in this thread he stated hes a front of the pack B rider. and its hard to sandbag when theres a promo points system regarding dungey.
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the second post by the OP in this thread he stated hes a front of the pack B rider. and its hard to sandbag when theres a promo points system regarding dungey.

You are absolutely correct. regarding the OP's stated ability. I apologize for that.

I mis-remembered (and should of re-read to ensure accuracy) his stating he was a front of the pack 'B' racer. No offense intended.

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You are absolutely correct. regarding the OP's stated ability. I apologize for that.

I mis-remembered (and should of re-read to ensure accuracy) his stating he was a front of the pack 'B' racer. No offense intended.

no problem just wanted to say it.

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