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the most basic ways to get more power out of a thumper. and underneath thse mods is more, what other mods that i didnt list that is fairly cheap but gives out good HP,performance (not graphics ETC) motor mods etc to make my bike faster, powerfuller, ETC its a kx250f 06.

HOPPED-UP GAS

There isn't an easier performance mod than pouring VP Racing's Ultimate 4 race gas in the tank. It only takes a few seconds and offers instant rewards. The increase in octane, power yielding oxygenents and hydrocarbons (with a greater energy potential) results in a fuel that can produce 6 percent more power than standard pump gas. That's a three horsepower increase on a 450 and two horses more on a 250.

EXHAUST SYSTEMS

With prices running as high as $800 for a titanium system, performance four-stroke pipes have become status symbols. As with a two-strokeÕs expansion chamber, a four-stroke exhaust system is tuned to produce the optimum powerband. The major elements of pipe design are: (1) head pipe length, (2) head pipe diameter, (3) overall tuned length, (3) taper of S-bends, (4) diameter of the muffler core and (5) length of the muffler. Unlike Formula 1 or road racing exhaust pipes, a four-stroke pipe has to deliver a broad and usable powerband--instead of maximum horsepower.

In the future, expect to see tapered head pipes, steps, stamped shapes and exotic metals (like Inconel) being used to deliver more low-end, a broader mid and extra top. Not only can aftermarket exhaust pipes add a horsepower or two, but they can save as much as five pounds over stock systems.

HIGH-PERFORMANCE CAMSHAFTS

Performance cams are available with lobes that are timed to open the valves earlier and to keep them open longer (known as dwell). As a rule of thumb, the best high-performance cams do their best work in the range where the power is already concentrated. The most noticeable camshaft change is in the way the power is delivered.

Automobile hop-up shops have done a bumper business in cams for decades. Motocross racers have not embraced different cam shapes, but this will change.

HIGH-FLOW PORTING

Unlike on a two-stroke, four-stroke porting is done in the head. There are no ports in the cylinder wall of a four-stroke. To properly port the head on a four-stroke requires a flow-bench. A flow-bench measures how much vacuum it takes to draw air out of the intake port and exhaust flange. Porting and polishing the cavities of a four-strokes cylinder head can increase the flow rate for more performance.

In some cases, larger valves can be fitted to improve the flow rate, but this mod normally only works on four-stroke engines of a lesser tune.

INCREASED COMPRESSION

One of the easiest ways to get a harder hit and better low-to-mid power is to increase the compression ratio. On a two-stroke engine, compression is increased by milling the head (which decreases combustion chamber volume). On a four-stroke, the compression ratio is increased by using a piston with a higher dome.

A high-compression piston typically delivers more punch at the cost of some top-end. Stock compression is typically in the 12:1 range. It can be upped as high as 13:1. Be careful, increases in compression might require higher octane gasoline.

BORED-OUT CARBS

As with a two-stroke engine, carburetors offer wonderful tuning opportunities. On most small displacement play bikes, like TT-Rs, KLXs and XRs, it is de rigeur to replace the stock carb with a larger one. The larger the bore of the carb, which is measured in millimeters, the more fuel it can flow.

As a rule, big carbs increase mid-and-up power (at the cost of low-end). Why do big carbs hurt low-end power? In order to flow fuel through a larger opening, the engine has to create more vacuum. The larger the carb throat the greater the vacuum required to draw the fuel into the engine. At low rpm settings, many four-stroke engines donÕt produce enough air velocity to get the fuel flowing--thus, low-end power is lost until the air flow is sufficient (at higher rpm). Conversely, smaller carbs flow fuel more easily, start better and have better throttle response.

CLUTCHES

The extra weight and torquier power delivery makes a four-stroke tough on clutches. If you pump up the horsepower with race gas, exhaust systems, big-bore kits, camshafts or flowed heads, the stock clutch may not be sufficient.

Hinson makes baskets, pressure plates and hubs that guarantee longer life.

WET SUMP

The Yamaha YZ250F and YZ450F can have their lubrication systems switched from dry sump to wet sump with aftermarket kits. These kits eliminate the YZ-Fs oil tank and, in the process, save two pounds of oil and oil lines. Wet sumping doesnÕt necessarily make a bike faster, but it does make it lighter. Wet sump YZ-Fs will need to have their oil changed more frequently.

In the future, a new breed of four-stroke oil will increase horsepower. These new oils will have the lubricating qualities of a 30-weight, but the viscosity of a 0-weight (comparable to water). These low viscosity oils will reduced drag on the mechanical parts and improve everything from throttle response to top-end.

MOD PARTS

boyeseen quick shot

power now/plus

I cat

hot cams

what other performance mods can you do? please list em!

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Gee, where did you cut and paste that info from? I hope you are not trying to take credit for writing that information. With the use of words like "powerfuller", I highly doubt that it is your doing. :thumbsup:

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um no why you gotta be an azz for dude. no im not trying to take cred for it no itts not mine and like a ear ago i got it off of some mag's site and i posted it on anoter forum long time ago n went back and got it.. i think people would like to know this info to dude..

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um no why you gotta be an azz for dude. no im not trying to take cred for it no itts not mine and like a ear ago i got it off of some mag's site and i posted it on anoter forum long time ago n went back and got it.. i think people would like to know this info to dude..

Let me guess, you're not competing in this years National Spelling Bee, are you. BTY, all that info is pretty much common knowledge for most TTers.

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Let me guess, you're not competing in this years National Spelling Bee, are you. BTY, all that info is pretty much common knowledge for most TTers.

Then why the hell are you so offended by it. For people that do not have that much knowledge it's great info and saves them from searching all day long for this info. Stop trying to pick a fight when it's not needed.

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Then why the hell are you so offended by it. For people that do not have that much knowledge it's great info and saves them from searching all day long for this info. Stop trying to pick a fight when it's not needed.

how can you fight over the internet? :thumbsup:

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Back to the original question about performance mods...

Not so obvious mods that have worked well for me are a quicker turn throttle and an oversize front disk. Also, because I have a big bore kit a lighter OEM flywheel.

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how can you fight over the internet? :thumbsup:

The definition of fight is not only a physical thing but can also be verbal or of some type of contest (Function: noun). But you already knew that, didn't you.

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The definition of fight is not only a physical thing but can also be verbal or of some type of contest (Function: noun). But you already knew that, didn't you.

nope. didnt know that.

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