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Bike Stolen - Need to get my 2-stroke up to speed!

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Hey guys,

Just recently had my 2009 KX450F stolen in Montana. Perhaps you have seen the posting on RacerX about it. I also have a link to the VIN and photo of it:

http://www.montanamotocross.com/

Please keep your eye's open if you are in the Montana or NW area!

Anyway,

My additional purpose for writing is I need to make my 2003 KX250 competitive with 450's without spending hundreds on it. I won't be able to afford another 450 this year for racing.

Can you guys give me some fairly inexpensive ideas???

So far its piped, with a Bills...Reed Valve (V-Force), Fresh top end, suspension has been done. I need Mo Power though!

Any advice would be great! Thanks guys...

Jason

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That sucks man! Keep an eye out on ebay too.

With what you've done already you could of had a reputable engine builder port the engine and mod the head. Aside from pipe and reeds there's really nothing else you can do that just a simple bolt and inexpensive, but pipe and reeds are actually expensive I think but here's what you can do-

Just as an example:

Eric Gorr does porting and head mods for 200, that includes cleaning the cylinder, porting to what kind of power you want and head modded for the fuel you want to run as well.

Big bore 265- 500$ and 285 600$

For that bike if your not looking to go big bore the cheapest option would to port and polish, Wiseco single ring racers choice piston with the TiN ring, and some carb mods.

200+125+100= $425

Good luck!

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make my 2003 KX250 competitive with 450's

I don't know why people think 250 smokers are underpowered compared to 450's, that's totally wrong. The 'delivery' is different, that's all. I can drag race 450's all day on my 250 - win some and lose some. I think some more time on it to get the feel back and you'll be fine.

Heck, I ride 250 smokers and a competitor of mine rides a 125, we usually finish top 4-5 in a vet class CHOCK FULL of 4 strokes.

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At elevation they are...I live at 4500 feet. Most of the tracks I race at are 4500-6000 feet.

EFI 4-strokes kill 2-strokes at elevation. Mine is jetted perfect through a jetting machine (from my local shop) that measures the exhaust fumes (of course this changes with temp/dryness of air/additional elevation gains, etc.) but I am just about right on the button.

I think my skills are about there, I just notice after about 4-5 laps the bike seems "tired" where as my 4-stoke had more than enough pep for 5 or 6 more hard laps without feeling "tired".

2strokenut: Thanks for the advice, I do know a shop that does porting and polishing, may have to swing in and talk with them. Thanks again....

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At elevation they are...I live at 4500 feet. Most of the tracks I race at are 4500-6000 feet.

EFI 4-strokes kill 2-strokes at elevation. Mine is jetted perfect through a jetting machine (from my local shop) that measures the exhaust fumes (of course this changes with temp/dryness of air/additional elevation gains, etc.) but I am just about right on the button.

I think my skills are about there, I just notice after about 4-5 laps the bike seems "tired" where as my 4-stoke had more than enough pep for 5 or 6 more hard laps without feeling "tired".

2strokenut: Thanks for the advice, I do know a shop that does porting and polishing, may have to swing in and talk with them. Thanks again....

tired? a bike shouldn't change its power characteristics or feel "tired" within a month, let alone 1 moto. are you overheating your bikes or something?

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I was gonna say, sounds like it's leaned out, too hot.

elevation will exacerbate that issue

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45-55 degrees right now. 165 main jet is perfect according to the "jetting machine" at my shop. It doesn't feel warm at all to the touch when I am done riding a moto. I do ride the piss out of it, but I remember my other 2 strokes doing the same. After 5 laps, I need to use the clutch twice as much to keep it on the pipe.

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45-55 degrees right now. 165 main jet is perfect according to the "jetting machine" at my shop. It doesn't feel warm at all to the touch when I am done riding a moto. I do ride the piss out of it, but I remember my other 2 strokes doing the same. After 5 laps, I need to use the clutch twice as much to keep it on the pipe.

something is definitely wrong with that

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With what?

after 5 laps having to struggle to keep it on the pipe, or the fact that it changes at all in such a short time span

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I would try to jet the bike to your riding ability. For instance, my 05 is jetted just fine for the way I ride it MX or woods, but if I put Jeff Emig on it for a couple laps he'd probobly toast my engine.

You may even be rich depending on the plug reading, the bike could be loading up on you. Would most likely happen if you weren't on the pipe most of the time.

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Just as a side note...I do race the Pro class (Vet & 450) as a top contender. When I ride, its full throttle....I am typically a top finisher in Vet-Pro and top 3 in the 450 Pro. I don't put put the bike.

I did change my clip position last night as per the jetting chart in our little green books. It was on the 3rd position (for riding in the winter temps) now I have it in the 2nd position. I also went to a 52 pilot (this is stock) from a 55 (winter riding again).

Here is a video from Horn Rapids a couple weeks ago. I am #808.

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I thought that too...but according to charts/temps/Elevation I actually should be at a 160 or 162 main. I am at a 165 main. The top feels just fine when I am there, no pinging or surging (Lean) or deep throaty sound like its rich. Its the low to mid. IDK...maybe I am just spoiled from my 4-stroke... :banana:

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I thought that too...but according to charts/temps/Elevation I actually should be at a 160 or 162 main. I am at a 165 main. The top feels just fine when I am there, no pinging or surging (Lean) or deep throaty sound like its rich. Its the low to mid. IDK...maybe I am just spoiled from my 4-stroke... :banana:

go up 1 on the main, just to experiment, ill bet your bike runs normal for a whole day

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First off, you need to jet for you don't use a machine because you don't ride like you jetted it. Typically the machine will give you a lean jet, seat of the pants will be at least one step richer. The 250 is as fast as the 450, what the 450 does is come out of the dry hard corners much better than the 250. On a moist rutted track a 250 will work as well. Most of the tracks in Montana fall under that dry hard corner category. if you want to make it more tractable install a flywheel, it'll take some of the snap out but make it easier to corner. I have an 06 250, the thing has killer power, can't imagine needing more unless you want to hillclimb it or something. By the way I did the big bore deal, it's sitting in a box in the corner blown up. cylinder is wrong.

I'm in Billings and know most people that have 09's I'll keep an eye out for it. I have fire and theft insurance on my bikes

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