Reeds or No Reeds?! KTM XCF-W EXC-F HQV FE FE-S

[@brad4619]

Appreciate you sharing your insight on this. I recently purchased a new KTM 500 EXC-F and I'm planning on doing the typical mods. The one thing I was on the fence about is the reeds. After watching this video I'm planning on leaving the reeds intact.

[@slaverace1]

Hello Brad: Suggestion: Check your reeds occasionally to make sure they are still intact and/or add some sealant to keep them in place.

[@jeffmcclain]

Funny (crazy?) story, I just got a new 2024 KTM 500 XW-F and took it out that first day for break-in ride and got through 50 miles of moderate, modulated and short pulls run. I normally don't avoid a full throttle pull, just don't let it linger or run too high RPM and let it cool periodically. Completely stock, and went for second ride 2 days later. Got through about 35 miles, and was on a pretty deeply whooped out section headed back to the truck. Had been running fine, not great low end torque as expected on these stock ECU with the stock spark restrictor and suddenly, I just hit a wall on the throttle response. At first, I thought I had run out of gas (or maybe these new upper pick-up fuel pumps was starved for fuel). Like a limped ECU. But it would idle ok (tend to die or flame out coming off throttle) but you could restart it and full throttle would just blubber and run super rich. No torque, couldn't even pull the bike up a 15% grade in 1st gear. Reset ECU battery disconnect. Check the fuel disconnect worried about plug, but didn't really see *any* check engine light or anything and nothing helped. We were almost back, so limped it back to truck 3 miles and just took it to dealer. Turns out, *somehow*, they think the reed block must not have been fully inserted to "clip" in from the manufacturer, and it had popped out back into the air filter (????) and then at some point through the whoops, it was tumbling/jumbling around until the intake vacuum managed to catch it and pull it in REVERSED into the slot. Now, it must have been fully pulled in (I didn't see it), because shutting it off and riding idle didn't fix anything, so it was in enough to not just fall back once vacuum was removed. I'm still incredulous that this happened (I wouldn't have ever bet any money on this ever happening), but with it being a new bike, I didn't even want to try checking too much. That's what the shop found. I still think they think I put it in backwards...but I had never had the filter even off... I wasn't sure I would remove them, with new ECU from vortex, even if I was removing all the vapor recapture emission stuff, but now, I'm inclined even if it doesn't HURT performance too much that I may just because...

[@slaverace1]

Thanks for sharing your story.

[@BrendanMcareavy]

This same thing just happened to me, 2024 Fe350s at 40 hours.

[@jeffmcclain]

@@BrendanMcareavy That's crazy. I still can't believe that happened. If I was someone else, hearing this, I wouldn't have believed it...10+ rides and 250-300 miles more since, and never had anything like it happen again...

[@vxe6vxe6]

I had a 2019 KTM 350 XCF. I pulled the reeds out, added a euro air boot, added a JD Tuner and an FMF power bomb pipe with the Q4 muffler. Plenty quiet, had great bottom end (for a 350), never stalled or flamed out. I added 2022 500EXC. I left pulled the reeds in, added a GET ECU and an FMF power bomb pipe with the Q4 muffler. Plenty quiet, has great bottom end, never stalls or flames out.

[@slaverace1]

Ok. Get out for some throttle therapy.

[@weswilliams4661]

Reeds in with a Slavens tuned GET ecu on map 2(mild map) is absolute perfection.

[@slaverace1]

Thank you. We appreciate your support.

[@bobrotert7247]

I have heard the reeds can possibly break and cause catastrophic engine damage. Jeff Any truth or have you had any experience with that.

[@slaverace1]

Bob: Yes, they can break but I have not experienced that or heard any complaints from customers.

[@dougderby9454]

When they first started coming with reeds. So many tuners and shops said leave them. There no gain with them out. I removed them on my 18 501 and changed the boot. Got a new end cap. Remapped. Seemed like a big difference to me.

[@slaverace1]

You're on the right track.

[@gophop]

It's a big difference. Gave my buddy a mapped ECU. He had the muffler screen removed but reeds in. After a couple of rides he thought it was a little better, not a game changer. I told him to rip the reeds out. 2 weeks later he did. Immediately texts me after a ride, "OMG it's a different bike!"

[@gcostanza2115]

Interesting to hear the sound difference and find out how the bikes compare from a performance point of view.

[@stevedecoy1630]

Good video, thanks Jeff. Do you feel the same way with the 350 XCF-W? Is it difficult to put the reeds back in? I have a stock '22 350 XCF-W and am getting ready to remove the reeds, put a different end cap on and install the JD Fuel tuner that I have already purchased because I just couldn't afford a ECU, and now after watching the video I am not so sure that I am headed the right way for single track. Again, thanks always for the great info!

[@slaverace1]

Hello Steve: It all applies to the 350. It's easy to re-install the reeds. Sorry, I'm not a fan of piggyback tuners.

[@danarussell4246]

Excellent video as always. I wish these videos were around when I use to ride enduros competitively back in the '80's. Jeff, have you evey put out a video how to winterize the newer 2 & 4 stroke bikes? Thanks as always.

[@slaverace1]

Hello Dana: There is really nothing that needs done to winterize. Maybe charge the battery once, but the best thing to do is ride it and don't park it. Head south for the winter, ha!

[@danarussell4246]

@@slaverace1 I have to admit I'm a little surprised at the answer. I really am clueless about the modern FI 4 strokes. I've been lazy before and left stale fuel in the bike over winter and the orange pumpkin was a PIA to start the next spring. I've left fuel with Sta-Bil in it and pretty much the same results. The year before I drained the tank and put fresh fuel in her and she started right up that spring. Did that again last year and she went back to being a PIA to get started. My old Vietnam vet says just put Sta-Bil in her and start her every couple weeks and let her run for a few minutes. I miss my old Husky 500 two smoker. She always started, you just had to make sure she didn't kick back and bite you. Thank you very much for the response. You guys are awesome.

[@HVACOG]

Do you need an ecu when removing the screen/ new cap? Or stock ecu will work okay? Thanks!

[@slaverace1]

Hello: The stock ECU settings (2017-2024) are TOO LEAN and performance is poor. When you make any modification that increases intake or exhaust flow, the fueling becomes even leaner. A correctly mapped Slavens Mule ECU slavensracing.com/product-category/electrical/ignitionecu-components/ is a must have item for great performance and longer engine life.

[@mototrailz]

No reeds on European bikes & Australian from the factory. But you need to remap either GET/AIm or Vortex for USA or your dealer in Europe can install the KTM unrestricted map. Also i used to be in the US with a 450 EXC and the reeds fell after 3000 miles...get a European air filter boot. Cheers

[@geoffcesmat8640]

I wonder if adding reeds to the airbox on a 300 2s would quiet down the intake drone. seems like the same issues would apply. would effect top power but if you hardly ever get above 6k rpm who cares.

[@slaverace1]

Hello: Adding reeds to the intake boot would quiet the intake vacuum noise but will also reduce HP throughout the powerband, not just the top end.

[@jaffro001]

Can you just pop the reeds back in ? Wanted to test it out but it’s a tight fit so wanted to make sure.

[@slaverace1]

Hello Yes you can re-install them. Use silicone sealant.

[@rayrokni]

Is it necessary to add an intake tube to the stock air box if you do remove the reed? Thx

[@slaverace1]

No.

[@damonmartinez3428]

Does the factory ECU with an O2 sensor adjust the fuel output of the injector to compensate for the added air intake from removing the reeds? Why do we need a new ECU to do that?

[@slaverace1]

Hello Damon: Unfortunately the Lambda (o2) sensor can only adjust for a small range of variances in elevation, temperature, humidity, etc. and cannot compensate for major changes in air flow from removing the reeds or changes to the exhaust system. That can only be corrected with a different ECU, slavensracing.com/product-category/electrical/ignitionecu-components/

[@damonmartinez3428]

@@slaverace1 Thank you, that helps me make decisions. You stated "or changes to the exhaust" . KTM offers the FMF 4.1 and they do not indicate a need to change the mapping of the ECU. Would one be good to go to make the exhaust change and not have to worry about a consistent lean condition and a need to change an ECU?

[@bobrotert7247]

Several years back you had a video saying take the reeds out of the 17- 20 bikes to make the bike run better. Have you changed your mind on that??? If so maybe pull down that video. I had left the reeds in my bike for years thinking it did give smoother power and I was always wondering if I should remove. That video you had before pushed me to remove them. Now it looks like you have changed your thoughts over time??

[@slaverace1]

Hello Bob: No change here. Some guys prefer the softer low-end power delivery with the reeds intact, but most others are like me and prefer the HP gain by removing the reeds. However, if the reeds are removed an ECU upgrade is necessary.

[@bobrotert7247]

Thanks for the reply Jeff, I really respect and appreciate your opinions and your putting this content out to share!

[@CP556]

How do you like the mx tech National shock?

[@joshuagmain]

What about the backfire screen on the air filter? Stay or go?

[@slaverace1]

I leave it in because the risk of fire is not worth the very small performance gain.

[@michaelfraley4901]

If you leave the reed in but pull the screen out, how will it run with stock ECU?

[@slaverace1]

Way lean.

[@madman432000]

wonder what would happen if I installed reeds in my 2016 500exc with the euro map.

[@motoxposse]

I would guess the reeds are to stop backfire from burning the air filter up?

[@slaverace1]

Hello: Actually they are to reduce noise.

[@rayrokni]

Last night i removed the reed on’24 excf 350. I took it out on a woods ride today. It lasted all of 5 minutes before i busted my shoulder😂 when i fell going over a little log section because as jeff mentioned, throttle response is not smooth with the reed out. Can’t remember exactly what happened all i know is going over a small log, it seemed like i whisky throttled and took off, landed on my one gods shoulder, the other busted about 7 years ago on mx track 🤣🤣🤣. So i reckon reed is going back in 😁

[@slaverace1]

Hello: Sorry you took a hard digger. I have mentioned in several videos that the throttle response is smoother with the reed left in, NOT removed. My 500 still has the reed intact and will remain that way.

[@rayrokni]

@@slaverace1 yup, seen the video, just wanted to see the difference, i reckon i actually felt the difference instead 🤣🤣. Reed is back in.

[@joeanania2257]

Seeing actual dyno results vs seat of pants with always changing parameters would be more conclusive for me.. Thanks for your opinion though ...:)

[@slaverace1]

Hello: Thanks for your comment. The video is about rideability, not HP.

[@joeanania2257]

@Slavens Racing well I think a good dyno man can see the changes....I have read dozens of comments from guys removing reeds with nothing conclusive...I removed my Reeds and did not notice a thing.. but I am quite sure a dyno along with Afr ,etc would show the changes while a human trying to duplicate every single parameter is difficult....I think we all have done a mod and it has had the placebo effect on us because we believed! Haha...Anyhow I am sure your results have a good basis and better than what else has been presented up till now....Have a good weekend..Joe

[@joeanania2257]

Another thing that could be huge is ECU differences since many guys say get,aim,etc ecu make a difference ..I'm pretty sure the maps are not exactly the same...have to compare apples to apples...

[@mikeburnett6222]

Good info Jeff!

[@slaverace1]

Thanks!

[@scottforti3194]

“I won’t even ride with someone who has a loud exhaust” you def should stay away from me and my supermoto friends

[@thecocooreo]

Supermoto braaap!!! best sound ever!