KLX300 owners,
One of you needs to take your dead stock KLX300, remove the secondary butterfly valve from it's shaft, take it to a dyno shop, have them install a PCFC, have them tune the entire operating range of the engine - All WOT ops should be set to 12.8:1 ( NOT 13, 13.1, 13.2, or any other bogus value..)

Current indications are that you'll net a huge power increase over the entire RPM range and at all loadings - with the possible exception of 9500 rpm on up where smaller gains may be realized.

Caveat: No one knows what power levels will be created as the ECM programming muzzles the power output thru the secondary throttle valve and matching fuel/ignition schemes. Both of which should be obviated with the removal of the valve and PCFC tuning.

The power charts will provide a baseline for further engine modding - possibly creating truly high performance KLX300's..

NEW INFO:
With secondary throttle valve removed, a PCFC installed, a Barker exhaust system installed, a lidless airbox, and a dyno tune that provides 12.6 -12.8:1 for all WOT operations, the KLX300 will produce around 27hp and 18 lb ft TRQ ( SAE at the rear tire ).

As usual, the peak numbers mean nothing compared to the radical differences in the power curve shape. In a nutshell, with above mods, a peep will be riding a whole new bike that only visually resembles the old one.

 

Crickets. That's because people that want a dual sport with more power get a DRZ or a real enduro bike, instead of turning their KLX into a moneypit for miniscule returns. There's no point in chasing horsepower with this platform; that's not the point, nor is it what this platform delivers. These bikes will never be "truly high performance".

 

Really not interested in myopic conjectures based on obtuse philosophy..

BTW, peeps, you can find posts such as the above - almost word for word - in every forum for every machine known to man, within the performance threads.

 

Sheesh, I need to dust off my monocle for this one...

You can find similar posts with other platforms, but you're a fool if you can't see how quickly the returns dimish with this platform. Coming from the same person that said a one horsepower gain is "extreme" though, I'm not surprised to find your frame of reference to be a little off. Our bikes are on the far slow end of the spectrum and spending hundreds of dollars to extract fractional horsepower gains is a fruitless path.

Sprockets are cheap and effective, and exhaust is great if you want to pay for the sound (I understand that completely) but beyond that, accept what it is and move on instead of trying to modifying it out of it's class.

 

Let me explain why your philosophy is flawed, your opinion worthless, and then touch on your ego...

Personalization of a bike - Ergo's, appearance, tire choices, and all things similar - such threads never elicit any broad spectrum negative responses.. You'll never find " Why did you put on those tires, seat, footpegs, handlebars, decal kit, ( etc) , your trying to make your bike into something it's not suppose to be..

However, threads regarding personalization of performance always brings, out of the woodwork, at least one peep whose beliefs are intolerant of performance personalization and whose ego forces a post spouting such..

I'll review for you, and anyone that may think as you do, the hard data of what is easily and simply achievable on carb'd KLX250's: Stock, Lidless w stock header, and finally, lidless with MCM and full FMF exhaust.
The EFI 300 should unmuzzle waay more increases over it's stock power levels than the percentages of increase below - but someone needs to perform the mod-work, dyno tune, and test the results.







.

 

Okay cool, now give us the rundown of how much it costed to break into the whopping twenty horsepower range.

 

That's because those items are worth the cost and effort. I paid $50 for my wider footpegs and they were worth it, made a big difference as they are 50% wider than stock. One dollar per one percent of gain is a great value. Tires were worth it too. I can't even tell you how much better a 90/10 tire is in the mud than our garbage stock 50/50 tires. But with power, you're starting with an engine that is already so mild and detuned that you're spending hundreds or thousands to still end up mediocre. That's what it is, is that you're still low HP, you're still slow, but you could have just gotten something at that point with real HP, plus way better suspension, instead of trying to put lipstick on a pig.

There are way too many other bikes to choose from to bother modding this engine for performance. If you want to go faster on the street or on the trail then there are several options that do that way, way better than a KLX that are going to maybe even still cost a bit more than a modded KLX but over literally twice the performance instead of an incremental gain, making them a better value and better riding experience. Plus then you have a better canvas to work off of in the future with a much higher performance ceiling.

 

Let me re-write your 1st sentence for you, then, you can re-write your other sentences ( If/when you ever gain control over yourself) :
"That's because those items are worth the cost and effort, IMHO." .

For the "new guys" in here, those performance gains are from the cost of a DJ carb kit and a slipon - so, totaling $150 - $400 depending on how much you want to spend on a slipon. The top performance mod-combo will add the cost of a header to the previous mix. Thru the years, all those that have chosen one or the other lidless mod combo have all said the same thing - It's like getting a whole new bike..

 

Nothing wrong looking for a few more HP. Getting a little more across the board would be great for basic mods and some tuning. The KLX300 is a nice little bike, and the fact that it is inexpensive makes spending a little bit on a few mods no big deal. The 300R curve may the "entitlement" that could be expected for relatively cheap on the 300 dual sport. Even the expensive bikes require some tailoring to suit individual riders, and with EPA requirements they are choked and de-tuned also. Based on the reviews, the CRF450L requires an aftermarket ecu to be rideable at low speed technical stuff. Quite a bit to spend after dropping 10k on a bike. I am not getting any younger and just got back into riding, so we will see how the KLX does this summer, but I am guessing it will be all the bike I want, and any HP improvements will be bonus, plus the fun of tinkering with the bike a little.

 

Funny how your original post is about EFI bikes but then you backpedal to carbed bikes to highlight low cost. That's because tuning the EFI bikes makes zero sense economically.

If you want data on a dyno tuned EFI 300 so bad then put your money where your mouth is.