2019-2026 Suzuki RM-Z 250

Haven’t ridden the newer 250’s only 450’s, and if little bro is anything like big bro you’ll want to get at least a slip on to not only open the bike up a bit  but also to lose the boat anchor of a muffler Suzuki uses 😂 I love the RMZ450 and the 2012 250 I rode years ago, but I really don’t think any manufacturer out there has a muffler near as heavy as Suzuki uses. 

https://www.vitalmx.com/forums/Bike-Builds,46/2021-RMZ-250-frugal-build-informative-thread,1386535

Lots of good info in this guys build

Read and listen to keefers website / podcasts on the rmz 250. They go through easy airbox and slipon mods to major mods.

I'm also considering the rmz 250.

I can get a low hour last gen rmz for half the price of a new bike in México. That makes it really appealing to me.

You’d be surprised at what a slip on does for the RMZ’s. We have done absolutely ZERO engine work to any of the RMZ’s we’ve had since 2013 other than pistons which are replaced with OEM only. These things are so corked up from the factory that the slip on alone really does improve them more than you’d think. It’s not just weight savings on the RMZ. 

We had a 2021 RMZ 250, forks were stiff, and we put in different springs. The bike was so much better, and didn’t beat you to death. Also put on a yoshimura slip on what a difference, brought the bike to life. These are great bikes with great reliability, so underrated.

I've been on one part time since 20. I thought my Twisted Vortex was a lot better mod for the money than my full Yosh system. After a couple of big time fails by a major suspension mod company I had the guys on the ThumperTalk suspension forum talk me thru a major fork revalve which finally got me there. I'm down three steps on the fork spring and two on the shock. Shock valving is still stock but I band-aided it with a link and some out there settings. The final piece that really solved my chassis issues was a Hinson BTL clutch, probably my favorite mod. It really unbinds the chassis thru the decel and braking bumps. Also did airbox mods, TwinAir proflow and some soft mounts. Mine is currently down for new valves and a high compression piston. My intake valves went bad just past forty hours, was running pump premium but I wasn't that hard on it, I'm almost seventy.

Did the the vortex help at all with the decel?

I didn't ride mine stock for long and put a full Yosh exhaust on it right away but I'd say start with:

-proper springs front/rear (cost me $260)

-Chop off ears inside side panels for more air (unless you're doing really muddy offroad race)

-Exhaust

Past that, a Vortex or GET ecu and proper engine mods make it rev farther and insanely snappy off the bottom.

 Edit 

-Agreed on the clutch springs! forgot about those

-As mentioned in regard to the GET ecu. That is my only experience with an aftermarket ecu as well, GET tuned by Dean Baker and it's awesome as mentioned.

-cut air filter screen out and/or Twin Air aluminum cage setup.  I ended up doing both.

Not really for what I was looking for. The Vortex did make noticeably more power than the most aggressive maps in the Suzuki GET programmer but didn't effect engine braking enough for my liking.  I did ride two strokes all the years I raced so I may be a little critical. .

Roczen runs one on his bike as well.

A big bore kit is a great addition to any 250F

https://youtu.be/Lw2jvhY38TE?si=SGvNi46kiAIoUAH8

My go to items are: Hinson clutch springs, JE high compression piston, DeVol adjustable linkage. Cutting the seat at the back and drilling the block (sorry, I don’t have a pic of that, but it’s obvious where when you take the seat off) that sits on the subframe cross member helps more than holes in the airbox. Best I can figure is having something to do with the overall air path and volume within the box. 


For off road and vet moto, I’d honestly stay with the oem box with the rm army map developed by pro circuit. Don’t waste your money on an aftermarket box if you don’t need a higher rev limit. 

Before people flame me for this statement, I’ve had 3 different vortex ecu’s mapped by twisted for this generation rmz250 and they all ran like crap, and EVERY guy who rode for my ax team that bought one from them all said the same thing and they had to start in 1st gear. They only ran well (no bog) with the seat and side panel off, or a million holes drilled, making me think they dynoed it that way. They’ll rev to 14,400 rpm, which frankly isn’t safe (I have broken valve guides to prove it). 

If you want an aftermarket ecu, the base vortex map is good, the GET mapped by Dean Baker (old JGR builder) is hands down the best, and he charges $125 vs. $400 for mapping. 

Screenshots of the maps I’d run on a stock ecu:

Cutting out the backfire screen is a free mod and will give it a bit more snap, also a quick turn throttle cam, you can make one yourself or buy one.

Do it.   Love mine and zero regrets.  

Any tips, I'm gonna attempt to change the maps on my 21 250f, haven't done anything like this before

I just realized my other screenshots didn’t load in my first post, I edited that to show all the adjustments made to fuel and ignition for both maps. Make sure to match the numbers in the white background left column and top row too, the app defaults to focusing on lower throttle openings if I remember correctly. 

Now, here's my step by step writeup of how to do it:

1:Download the GET tuning app, called "WiGET" in the app store.

2: locate your wifi com box that came with the bike, AND the power cable (it's a black cord with a red fuse that has terminals to connect to a battery on one end and the wiring harness on the other.

3: Plug the wifi box in to the empty connector on the right side of the bike below the fuel tank area (it's right next to where the fuel pump plugs into)

4: disconnect the connector that's behind the left radiator shroud (smack dab in the middle of the shroud, behind that super long bolt is where to look) from the dummy plug.  Now plug the power cord into that port, and connect the battery to your power cord if you haven't already.

5: your wifi box will flash some lights, then stay steady.  Connect to the Wifi network it provides, and use the password on the back of the box (printed on the silver sticker) to access the wifi.

6: Open the WiGET app, and connect to the bike that's now sending a WiFi signal.

7: To tweak any maps, tap twice on the cells in the spreadsheet you want to edit and use the arrows to adjust + and -.  For the 250 PC maps, you'll also need to adjust the throttle points on the left column as well.  The default screen is to adjust the ignition timing, and at the top you'll see "FI MAP" to the right of "IG MAP", select "FI MAP" to adjust your fueling.

8: Once the changes are made, use the arrow pointing up in the top right of the screen to send the map to the bike.  The map you've sent is now loaded in, and accessed by whatever coupler you have installed at the moment.

9: Install another coupler and upload a different map to test back to back.  You can have 3 maps in the OEM ecu, the couplers acts as a key to access them, or you can build a homemade map switch with a 3 position switch and cannibalizing the black coupler (that's a tale for another post).

Hope this helps!

Thank you! Thats a perfect write up I'm going to give it a shot this weekend 

I bought a 2019 a few years ago to be used strictly as a track bike , no trails or off road type riding. Due to unusual circumstances I started to trail ride it.....the suspension got the typical spring change with internal pressure spring change as well. With the longer races I needed a bigger tank so an IMS unit was found. One of the best changes for higher speed GP type races was a 14t front sprocket.