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Crf250l power/torque mods

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Was wondering if the full fmf, k&n air filter, ejk makes truly enough difference in power for $900... was also thinking about keeping the stock front sprocket and adding a 42T rear... would that 42T rear make a decent difference in torque?

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For me, it made the 250 a viable option for highway cruising and touring when loaded. Before the mods, it just wasn’t fast enough. Without the mods, I would have had to go to a bigger bike. I am happy with the mods. 

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For $900 I would explore a CBR300R engine swap or doing the CBR300R crank upgrade. I went through the stage 1 mod route, then CBR250R ECU and throttle body, but for the money the crank delivers the biggest torque improvement. If I had to do it again, with $1000 I’d start there (assuming I was okay with the suspension). I run 14/39 gearing and the bike pulls great. One of my friends runs 15/38 on his CRF that has the CBR300 engine transplant, but the gearbox has slightly different ratios than the CRF

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PS I went this route rather than a big bore for reliability, my upgraded engine is 100% Honda production parts and should retain its durability. I was aiming to build a bike capable of a 5000 mile 2 week mixed use touring capability. With improved screen and a Seat Concepts Seat I can do consecutive 10hr days and cruise unstressed at 70mph

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For me, the FMF pipe & muffler, & EJK tuner, were never in question. I don’t ride quiet bikes on the streets. Too dangerous. I may one day look into swapping the TB on my 2014 for a larger one, and corresponding ECU, but I am not interested in opening the motor. Pretty happy with that little beastie. 🙂

My next step is likely to put in new clutch plate to get rid of the judder spring setup. 

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I've done all of the above plus the clutch, Race Tech front end and Hyper Pro rear. Biggest improvements were removing the judder spring and better tires.

Edited by Evan D
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I can only speak to the 13-16 models(mine is a '16), but It's definitely worth it, although there are some differences in what mods each of us actually does, and what our goals are.  I ride mostly street with 17" SUMO wheels, but do occasionally swap to the stock wheels with knobby AC10s to run trails, so top end and highway performance is more important than low end pop to get over offroad obstacles.  Did some protection/body stuff, but my engine/drive mods, FMF Q4 with powerbomb header, EJK, 2" snorkel mod, cut backfire screen, '17 throttle swap, EBC clutch(judder eliminate), stock 14-40 gearing for SUMO wheels, 13-42 on stock wheels/knobbies.  Have the Warp 9 SUMO kit with sticky 17" Pilot powers, 320MM front rotor, and full Racetech spring/valve in front and G3S custom shock in the rear, it is nothing like the stock bike onroad, 20MPH higher top-speed, muh better acceleration, sport-bike like handling and a smooth stable ride.  Gearing can help or hurt depending on what you want to get out of the bike, usually it's the balance between a low first for offroad use, and a useable 6th for use on the highway at comfortable RPM.  Most offroad bikes basically have gearing where their second is around the L's first, would take 13/45 or lower to get close, but you would red line before 80, and it would probably be buzzy above 60.  You can get the best onroad performance by gearing where you are at the tail end of peak power at top speed, 14-40 on a 150/60r17 is about right, somewhere around 13/40 or 14/42 with stock tires.  In my case, I could probably go a little taller, maybe 14/38-39 keep a good top speed, but make it a little more comfortable cruising around 75.  On the stock tires, i like 13/42, it's a good compromise that is just tall enough to be comfortable on the highway, and just low enough to do well offroad.  Ended up putting probably too much money in the bike, enough to probably buy a much more powerful street bike, or a nice DRZ SUMO, but it's still a nice simple and friendly Honda that now is much more capable anywhere, from offroad enduro trails on knobbies, to highways and twisty roads on the SUMO wheels.

When I first bought the bike, I thought I made a mistake, could barely hold 70MPH(by GPS), topped out in 5th, slowed down in 6th, slippy spongy clutch feel, and while it pulled well low-end, it was sluggish to rev.  I test ride on a flat road both ways to see what the top speed is, and judge mods, granted temps and weather make a difference, but it is better than nothing.  It did improve a small bit after 500 miles and the clutch mod, engaged FAR more consistently, and held much better.  The Q4/PB exhaust, cutting the backfire screen, removing the snorkel,  and EJK improved top speed by 10mph to 80, but most noticeably throttle response was better, and it reved much quiker, with less drop-off around 9K RPM, but the exhaust was a bit loud and raspy for my tastes around town.  Swapped in the smaller 1 1/8" quiet core in the Q4, and LOVE IT, much deeper, more mellow and powerful tone, quieter and nice on longer rides, but still a huge improvement from stock, also made an oversized 2" snorkel from a rubber plumbing elbow, cut out the top of the airbox to seal it, and it ended up allowing me to add a little to the top-end fueling from the EJK, and in turn increased power throughout the rev-range, the smaller muffler insert may have boosted low-end, but if nothing else it didn't hurt top-end, top speed, got my SUMO wheel set, and managed 86MPH on my test spot.  Probably the best bang-for-the-buck mod on 13-16 models is to swap in a '17 throttle, it is a $38 part, all sensors, brackets, and cables are a 100% direct swap as the 36 and 38mm throttles are identical outside of the bore and plate diameters, this alone improved top-end most noticeably above 7K, top-speed hit 90MPH for the first time ever, and it smoothed out the power delivery and sped up the throttle response about as much as the initial EJK/exhaust did.  Now the bike can hold 80+ up hills with ease, actually pass traffic on the interstate, and I feel a much more direct connection through the throttle and clutch, it's a different bike that I am happy with, and can do FAR more than I could out of the box, have probably $1K in power/clutch mods with only a couple hours worth of work to install and tune them.  Probably still less power than a 300 swap or big-bore, but my wife has a CB300F with only a slip-on, and my bike basically will run neck and neck with it up to 90, which is about where both top out at, so it feels close.  It's also 100% bolt-on with no need to change ECUs, rewire anything or mess with tuning outside of my EJK settings(1.5-3-5.5), it's still factory reliable with the cost of the parts being the only real downside.

Edited by alucard0822
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Sounds like an excellent next step.

Is this the part? 16410-KZZ-D21  BODY SET   $41.24

No additional gaskets or anything? I have the Q4, Power Bomb and EJK along with airbox mods too. How different were your EJK settings between the two?

 

On ‎9‎/‎2‎/‎2019 at 11:39 AM, alucard0822 said:

Probably the best bang-for-the-buck mod on 13-16 models is to swap in a '17 throttle, it is a $38 part, all sensors, brackets, and cables are a 100% direct swap as the 36 and 38mm throttles are identical outside of the bore and plate diameters, this alone improved top-end most noticeably above 7K, top-speed hit 90MPH for the first time ever, and it smoothed out the power delivery and sped up the throttle response about as much as the initial EJK/exhaust did.  Now the bike can hold 80+ up hills with ease, actually pass traffic on the interstate, and I feel a much more direct connection through the throttle and clutch, it's a different bike that I am happy with, and can do FAR more than I could out of the box, have probably $1K in power/clutch mods with only a couple hours worth of work to install and tune them.  Probably still less power than a 300 swap or big-bore, but my wife has a CB300F with only a slip-on, and my bike basically will run neck and neck with it up to 90, which is about where both top out at, so it feels close.  It's also 100% bolt-on with no need to change ECUs, rewire anything or mess with tuning outside of my EJK settings(1.5-3-5.5), it's still factory reliable with the cost of the parts being the only real downside.

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12 hours ago, Evan D said:

Sounds like an excellent next step.

Is this the part? 16410-KZZ-D21  BODY SET   $41.24

No additional gaskets or anything? I have the Q4, Power Bomb and EJK along with airbox mods too. How different were your EJK settings between the two?

 

That's it, no gaskets, the rubber grommets fit fine, everything bolts right up.  They are identical externally, only difference is the larger bore.  I didn't have to recalibrate the TPS or adjust the min idle screw, just transfer sensors and cables, then slap it in.  Figured it would change EJK settings, but the power increase was there at the same 1.5,-3-5 I had set before, bumped the "red" to 5.5 and it may have increased a hair, or at least didn't loose any power, so that is the only change I made.

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19 minutes ago, Evan D said:

Thank you!

welcome.  Considering the benefits, relative ease of install, and fact it cost less than a K&N air filter, IMO the '17 throttle is a "must have" for 13-16s with an EJK.

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Was wondering if the full fmf, k&n air filter, ejk makes truly enough difference in power for $900... was also thinking about keeping the stock front sprocket and adding a 42T rear... would that 42T rear make a decent difference in torque?


You should read my so much for so little. Me and a friend have been playing around with the fmf and controller and it would seem as though it does nothing but sound. The 42t lightweight sprocket and light weight tubes coupled with the k&n are yielding measurably better results for “us”. Your mileage could vary. But racing 2 machines side by side the the lightweight sprocket tubes and k&n win over the fmf and programmer every time in a drag race. We even switched bikes.

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