I have a Beta 300 RR 2016 and was debating the Spheres for the forks. Stillwell did a decent job on revalve, but they could still use some help. We ride some similar terrain but mixed in with a lot of open desert, so the 250 might be slightly under powered for me on longer climbs. Have you felt much lacking on the 250 vs your experience with 300s? I don't mind fighting a bit more engine gyroscopic on the 300 (realize in tight woods turn to turn the 250 is more nimble). Would have to be substantial handling differences for me to give up that stellar Beta power (slavens mule on it currently). Thanks for any feedback:)
Great videos most of my mods have been influenced by your videos. I have similar mods on my 17 exc apart from the sxs heat metering block and exhaust pipe the bike runs great. Will we see a pro's and con's reviesw of the carb over the tpi
The red power valve spring will 100% affect how the bottom end feels. Ive seen the comments on ktmtalk about not changing and I don't buy it at all. I have a 300 tpi and ill be adding the red spring soon as I can ride again
The secondary power valve spring (the colored ones: green (stiff), yellow (medium) and red (light)) only affect about 5,500rpm and above. The bottom end will be affected by the dolly screw setting. James Dean at JD Jetting has done extensive dyno testing to prove this. Going from a yellow spring to a red spring would increase the power and torque above about 5,500rpm. Unless the dolly screw is changed there will not be a significant difference below about 5,500rpm. On my 2017 I use the red spring and really like it. I've set up my carb so it runs well with the red spring. With TPI you'd need to add fuel if you use the red spring, or risk having an overly lean mid range. That's not a risk I want to take, so will wait until I have a custom ECU which can richen the fueling, before I try the red spring.
Have you ever changed your spring because I promise you if you do you will not think that way. JD and all these dyno guys are the same thing. They tell you what the computer tells them but they don't give you real world experience. JD's jetting kit sucked so bad on my new 18 tx 300 that I jumped at the opportunity for a 300 tpi. I don't care what these guys stats say, if you put in the red spring and don't notice better bottom end hit right away. Ill kindly crawl into a hole. It's night and day. It''s easy to try, takes less than 5 minutes to swap. I know lots of KTM's own test guys run the red spring.
Yes, my 2017 KTM 250 EXC came stock with the Yellow spring. I run it with the Red spring. Going from the Yellow to Red spring I didn't notice a significant change in the bottom end. By bottom end I mean before the power valve opens. The way I think about it is that it doesn't matter what PV spring is fitted if the power valve is closed. What did change the bottom end significantly was going from the stock Mikuni carb to a Keihin carb. Night and day difference. Also adding an FMF Gnarly pipe improved the bottom without changing the top end noticeably. My current setup is the Red PV spring, a Keihin 38m Air Striker Short + STIC metering block, VForce4 reed cage, FMF Gnarly + Powercore2, SX Head and the bike rips from top to bottom. So much fun to ride.
As I mentioned in the video, the reason that I have not tried fitting the Red spring in my TPI is that I was told it will cause the midrange to become leaner. There is a risk that this may cause the bike to run excessively lean and possibly cause damage. As I intended to fit a custom ECU which can add more fuel, as soon as it's ready (1 month from now?), I don't mind waiting until then to fit the Red spring. And yes, I absolutely intend to use the Red spring...
You should run the fan using the factory relay and let the ecu control when it switches on and off. I've been running my bike like this for over 100hrs in extreme tech conditions where the fan works over time with no issues. On all my other bikes I've had, I have always needed a manual override switch not with the TPI
I was considering mounting a relay and using the factory power connector and ECU to control the fan. But I didn't have the required relay and wanted to install it for the ride last weekend as it's very hot now. If I have any issues I can easily install the relay and re-connect it.
Hello, I've recently purchased a 2019 husky TE300i. Your vids on the tpi ktm have been a great help on modding the husky. I ordered the TOR odt kit and look forward to using it. Was curious though which front brake disc brake guard are you using? Thanks for your vids, I look forward to all future tpi vids. O.R, Reno, nv
Thanks for your order. If the shipping goes smoothly you should receive it by the end of the week, or early next week. The front disk guard is made by 7602 Racing: www.7602racing.com/product-p/ktm-fdg01-o.htm So far I really like it. Nicely made, light weight and looks strong (haven't hit anything yet to test it).
Eli Smigel - It is not recommended to add oil to the fuel in the TPI bikes. Adding oil would actually make the mixture leaner, although you would have more oil. Another issue is that you may clog the fuel injectors. My recommendation is to talk to your dealer and make sure you have the latest map. My bike does not run lean...
I can relate to cost, I have 2 ktms and Ive spent more than the cost of a bike on suspension .... complete Ohlins forks and shock on bike #1, Ohlins insert and KYB insert forks for bike #2. My dream is KTM will start using KYB suspension !
It's an FMF Powercore2. Light weight, compact, easy to overhaul and excellent value for money (about $120). Note that it does not have a spark arrestor, so if you need one look at a different model.
Yes, I can absolutely can recommend the 250 TPI. It's an easy bike to ride off-road and with some mods can grow with you as you become more comfortable on it. A 125 would probably be a lot more difficult to ride, depending on the terrain you ride and your weight.
I haven't ridden a 300 TPI yet, but I have ridden many different carbed 300s. I don't just want more bottom end power. I prefer the responsiveness, linear power, broad power band and light weight feeling of 250s. My 2017 KTM 250 EXC rips from top to bottom and is so much fun to ride. I'm hoping the TPI 250, with a few mods including custom CPU and head, will perform in a similar way. Another reason is that bikes over 250cc in Japan need to pass stricter emissions regulations and as such you can't legally register a new 2-stroke 300.
I'd offer you a go on my 2017 250 if you were close. I think that would really surprise you. It develops strong power at all RPM, and is very linear and responsive. Everyone who rides it comments that the power is strong, but it's also easy to ride.
My 300i Husqvarna has noticeably more low end grunt than my friends 250i but once they are moving there isn’t much between them. Re handling/ feel- I honestly don’t get the consistent theme of the 250 feeling lighter or more responsive, they feel identical to me. At all speeds.
The 300s I've ridden recently (2014, 2016 and two 2017s), have felt strong off the bottom, but when revved felt somewhat flat and unwilling to rev out like a 250. However, I know the 2017 250s were not good at all out the box (including mine) and required some help to get the real potential out of the engine.Of course personal preference also comes in to play, so I can see why many people like 300s.
@@TokyoOffroad I cant use the second gear on hard stuff , you have the same problem ? i think the 13 :52 would be better , what you think ? i have the 250 2019 me too
Lazaroiu Stefan - I’ve made a few changes to improve power including: RK Tek head, FMF Gnarly pipe, red power valve spring. It pulls well in 2nd gear, but I also use 1st gear quite a bit.
Tokyo Offroad hi.. Powercdi is the Italian manufacturer? Also one question... My 2018 has lots of pipe bang... Experiencing any? Can't discern it on the video...
Yes, I have stabilization switched on. I do not do any post processing (due to time) so rely on the camera to produce watchable footage. If you look at my visor in the upper corners of the video frame, you'll see it move which is due to the stabilization
Curious, did you run the stock pipe before you switched the aftermarket FMF? Was told that since you can't change your jetting a pipe that changes performance can sometimes have negative effects...until you get a powercdi that is.
I tried the stock pipe during 1H of break in riding. My feeling is that the stock pipe did not give it more low end power and torque. The TPI tractors up moderate inclines at low RPM well at steady throttle, but if you open the throttle up wanting to accelerate, or lift the front wheel to clear an obstacle it seems a bit lacking. I'm keen to improve this. Hopefully a custom ECU and a different head will improve it. Don't forget that I made many performance changes to my 2017 KTM 250 EXC, including carb (Keihin 38mm Air Striker Short + STIC metering block), SX head, FMF Gnarly pipe and VForce4 reed block) and this is my benchmark for how well a 2-stroke 250 can run. If I was comparing a totally stock 2017 to a stock 2019 TPI I'd say the TPI runs better. But who leaves their bike stock? ;-)
Jon Jelen - The bike in TPI (Transfer Port Injection) which is fuel injection. As such it doesn’t have a carb (it has a throttle body and injectors). The first performance mods will be to change the head and use a custom ECU.
You can't legally plate 300 2-strokes in Japan as they will not pass the stricter emission limits imposed on engine capacities over 250cc. The other reason is I like how 250s run (more responsive, faster revving and feel lighter than 300s). My 2017 KTM 250 EXC with a Keihin 38 + STIC, RK Tek head and FMF Gnarly pipe runs very strong. My 250 TPI runs pretty good now with an RK Tek head and FMF Gnarly pipe. This year I plan to fit an aftermarket ECU and see how much the performance can be further improved.
Tokyo Offroad fair play 👌🏻 I run a gnarly front and powercore 2 on my ‘19 300 which massively improved low and mid torque and the bike is much more responsive.
The bike stock comes with no guards and no fan. IMO you can save money by fitting guards (skid plate, disk guards) and prevent damaging the engine through overheating by fitting a fan. I ride one, or two days a week, year round and consider that I get my money’s worth out of the farkles I put on my bike. Regarding engine, suspension and ergonomic mods, they are open to debate and very much come down to personal preference. Either way I enjoy modifying my bikes to suit me better and maximizing my pleasure while riding then.
I'd rather spend the money on parts when I first buy the bike (especially guards) than wait, damage something, not be able to ride, have to replace the part (E.g. engine case, brake disk, or radiators) and then put a guard on. I've been riding off-road for almost 40 years so have quite a bit of experience regarding how to help prevent damage to the bike. In my opinion using guards is a good idea for off-road day riding even though I know they add weight and cost money.
Michael Wall - If depends how you like your bike to run. Completely stock the power is quite mild, but does hook up well in low traction conditions. I prefer more responsive power and like how the bike runs with an FMF Gnarly pipe and RK Tek head
That's a question I get asked a lot. One reason is that you can not register new 2-stroke bikes over 250cc in Japan. The areas I like to ride require a registered bike. The second is I prefer the response and power characteristics of a well tuned 250 over a 300. Several of my friends have put 300 kits on their 250s. The low end torque increases, but the power feels flat on top compared to a 250. Personal preference...
Tokyo Offroad although I've had a tpi 250 and 300 and find the 300 to be a lot more responsive, have better top end legs and more torque down low as well .
P.O.D Enduro - I have no doubt that the 300 TPI rides better stock. But buying a 300 TPI isn’t an option for me (due to registration rules in Japan). Therefore I will be modifying my 250 TPI with head and ECU changes and hope to get it performing well. My 2017 KTM 250 EXC flat out rips with a Keihin 38 Air Striker Short and STIC metering block, so this is my benchmark of what a well tuned 250 should run like.
Great video. I look forward to your future tpi videos
I have a Beta 300 RR 2016 and was debating the Spheres for the forks. Stillwell did a decent job on revalve, but they could still use some help. We ride some similar terrain but mixed in with a lot of open desert, so the 250 might be slightly under powered for me on longer climbs. Have you felt much lacking on the 250 vs your experience with 300s? I don't mind fighting a bit more engine gyroscopic on the 300 (realize in tight woods turn to turn the 250 is more nimble). Would have to be substantial handling differences for me to give up that stellar Beta power (slavens mule on it currently). Thanks for any feedback:)
Very attraction video!!!! Nice day guy!!!
Did I make it up last time?? No ... Ok, I'll go this way :)
Where's the fun in that? :-)
Great videos most of my mods have been influenced by your videos. I have similar mods on my 17 exc apart from the sxs heat metering block and exhaust pipe the bike runs great. Will we see a pro's and con's reviesw of the carb over the tpi
Good idea. Once I have the TPI performance dialed in I'll make a video comparing it to my carb 2017 (Keihin 38mm Air Striker Short + STIC)...
The red power valve spring will 100% affect how the bottom end feels. Ive seen the comments on ktmtalk about not changing and I don't buy it at all. I have a 300 tpi and ill be adding the red spring soon as I can ride again
The secondary power valve spring (the colored ones: green (stiff), yellow (medium) and red (light)) only affect about 5,500rpm and above. The bottom end will be affected by the dolly screw setting. James Dean at JD Jetting has done extensive dyno testing to prove this. Going from a yellow spring to a red spring would increase the power and torque above about 5,500rpm. Unless the dolly screw is changed there will not be a significant difference below about 5,500rpm. On my 2017 I use the red spring and really like it. I've set up my carb so it runs well with the red spring. With TPI you'd need to add fuel if you use the red spring, or risk having an overly lean mid range. That's not a risk I want to take, so will wait until I have a custom ECU which can richen the fueling, before I try the red spring.
Have you ever changed your spring because I promise you if you do you will not think that way. JD and all these dyno guys are the same thing. They tell you what the computer tells them but they don't give you real world experience. JD's jetting kit sucked so bad on my new 18 tx 300 that I jumped at the opportunity for a 300 tpi. I don't care what these guys stats say, if you put in the red spring and don't notice better bottom end hit right away. Ill kindly crawl into a hole. It's night and day. It''s easy to try, takes less than 5 minutes to swap. I know lots of KTM's own test guys run the red spring.
Yes, my 2017 KTM 250 EXC came stock with the Yellow spring. I run it with the Red spring. Going from the Yellow to Red spring I didn't notice a significant change in the bottom end. By bottom end I mean before the power valve opens. The way I think about it is that it doesn't matter what PV spring is fitted if the power valve is closed. What did change the bottom end significantly was going from the stock Mikuni carb to a Keihin carb. Night and day difference. Also adding an FMF Gnarly pipe improved the bottom without changing the top end noticeably. My current setup is the Red PV spring, a Keihin 38m Air Striker Short + STIC metering block, VForce4 reed cage, FMF Gnarly + Powercore2, SX Head and the bike rips from top to bottom. So much fun to ride.
I agree with the entire setup for your carb bike. Trust me play with the red spring on the tpi, Lafferty and Bobbit both run it and they test for ktm
As I mentioned in the video, the reason that I have not tried fitting the Red spring in my TPI is that I was told it will cause the midrange to become leaner. There is a risk that this may cause the bike to run excessively lean and possibly cause damage. As I intended to fit a custom ECU which can add more fuel, as soon as it's ready (1 month from now?), I don't mind waiting until then to fit the Red spring. And yes, I absolutely intend to use the Red spring...
They advise you not too change the power valve spring on the tpi only on the Caby model
Yes, KTM advise not to change the power valve spring on the TPI bikes. I haven’t tried changing mine yet.
You should run the fan using the factory relay and let the ecu control when it switches on and off. I've been running my bike like this for over 100hrs in extreme tech conditions where the fan works over time with no issues. On all my other bikes I've had, I have always needed a manual override switch not with the TPI
I was considering mounting a relay and using the factory power connector and ECU to control the fan. But I didn't have the required relay and wanted to install it for the ride last weekend as it's very hot now. If I have any issues I can easily install the relay and re-connect it.
Hello, I've recently purchased a 2019 husky TE300i. Your vids on the tpi ktm have been a great help on modding the husky. I ordered the TOR odt kit and look forward to using it. Was curious though which front brake disc brake guard are you using? Thanks for your vids, I look forward to all future tpi vids. O.R, Reno, nv
Thanks for your order. If the shipping goes smoothly you should receive it by the end of the week, or early next week.
The front disk guard is made by 7602 Racing: www.7602racing.com/product-p/ktm-fdg01-o.htm So far I really like it. Nicely made, light weight and looks strong (haven't hit anything yet to test it).
is it ok to put a bit of oil in the fuel tank as well so it's not as lean?
Eli Smigel - It is not recommended to add oil to the fuel in the TPI bikes. Adding oil would actually make the mixture leaner, although you would have more oil. Another issue is that you may clog the fuel injectors. My recommendation is to talk to your dealer and make sure you have the latest map. My bike does not run lean...
@@TokyoOffroad Ok thanks for replying. I will talk to my dealer.
What setup jarvis is running with his factory team in regards to engine management? I heard shaving head 25 thousands does wonders
Did you leave the WP explors on his bike ? Are the dal soggi's (forgive spelling) much better ?
Yes, the suspension is totally stock. On my 2017 I have Dal Soggio Sphere closed cartridges which I really like, but they aren’t cheap...
I can relate to cost, I have 2 ktms and Ive spent more than the cost of a bike on suspension .... complete Ohlins forks and shock on bike #1, Ohlins insert and KYB insert forks for bike #2. My dream is KTM will start using KYB suspension !
I have test rode a 250 tpi and a 300 tpi i must say i like the 300 way more. The exc250f is really Good to has alot of torque and is really light.
That cdi ecu looks interesting on thumpertalk
Jerry Mangan - Yes, I’m confident it will make a big improvement to the bike. Can’t wait to try it.
Can you do a quick video on your camera setup and preferences?
Yes, I'll add that to the list...
Hi have one question please... why buy the 250 and not the 300... is because the price diference?
xano preference
Ok... but is the 300 more dificult to ride because of the extra power... i have a 350 exc-f and am thinking on going again to the 2stroke engines
Of course it is, go 250, if your unsure mate
Thanks
Looks like you installed aftermarke exhaust muffler which is pretty short. Which one do you use?
It's an FMF Powercore2. Light weight, compact, easy to overhaul and excellent value for money (about $120). Note that it does not have a spark arrestor, so if you need one look at a different model.
Hey man would you recommend this bike for me to begin getting into the 2 stroke world or should i stick with getting a 125 xc-w
Yes, I can absolutely can recommend the 250 TPI. It's an easy bike to ride off-road and with some mods can grow with you as you become more comfortable on it. A 125 would probably be a lot more difficult to ride, depending on the terrain you ride and your weight.
Tokyo Offroad thank you very much 🤜🏻
Seems to have plenty power to me!
Mark, are going with vortex by tohyo mods fot cpu?
Jerry Mangan - No, I’m on the waiting list for a PowerCDI ECU
If you want more bottom end why not ride a 300?
I haven't ridden a 300 TPI yet, but I have ridden many different carbed 300s. I don't just want more bottom end power. I prefer the responsiveness, linear power, broad power band and light weight feeling of 250s. My 2017 KTM 250 EXC rips from top to bottom and is so much fun to ride. I'm hoping the TPI 250, with a few mods including custom CPU and head, will perform in a similar way. Another reason is that bikes over 250cc in Japan need to pass stricter emissions regulations and as such you can't legally register a new 2-stroke 300.
Tokyo Offroad I was unaware 250's have more linear and broader power. I'll have to jump on one and test it out. Cheers 😃
I'd offer you a go on my 2017 250 if you were close. I think that would really surprise you. It develops strong power at all RPM, and is very linear and responsive. Everyone who rides it comments that the power is strong, but it's also easy to ride.
My 300i Husqvarna has noticeably more low end grunt than my friends 250i but once they are moving there isn’t much between them. Re handling/ feel- I honestly don’t get the consistent theme of the 250 feeling lighter or more responsive, they feel identical to me. At all speeds.
The 300s I've ridden recently (2014, 2016 and two 2017s), have felt strong off the bottom, but when revved felt somewhat flat and unwilling to rev out like a 250. However, I know the 2017 250s were not good at all out the box (including mine) and required some help to get the real potential out of the engine.Of course personal preference also comes in to play, so I can see why many people like 300s.
Have you managed to track down a workshop manual for the TPI yet?
I ordered the 2019 TPI Repair Manual DVD from my KTM dealer and was told it isn't available yet and will arrive in October 2018
Motocross is my life
What gear sprocket settings do you have ?
I use 13:50 on my 250. Phil uses 12:50 on his 300.
@@TokyoOffroad I cant use the second gear on hard stuff , you have the same problem ? i think the 13 :52 would be better , what you think ? i have the 250 2019 me too
Lazaroiu Stefan - I’ve made a few changes to improve power including: RK Tek head, FMF Gnarly pipe, red power valve spring. It pulls well in 2nd gear, but I also use 1st gear quite a bit.
What kind of custom ECU you want to try? GET or PowerCDI?
PowerCDI
Tokyo Offroad hi.. Powercdi is the Italian manufacturer? Also one question... My 2018 has lots of pipe bang... Experiencing any? Can't discern it on the video...
I installed PowerCDI on my 2017 250 EXC and it solves the pipe bang perfectly! I will not get TPI until he releasing the TPI version.
Yes, PowerCDI is in Italy. Pipe bang on my bike is not that bad at all.
Same. Can't wait!
Does this have a break light
Yes, it does. It's road legal with rear light, brake light, turn signals, headlight and mirrors.
Sounds smooth in its std form
What was this recorded on? Session 5?
Yes, GoPro Session Hero 5
Yes, I have stabilization switched on. I do not do any post processing (due to time) so rely on the camera to produce watchable footage. If you look at my visor in the upper corners of the video frame, you'll see it move which is due to the stabilization
Curious, did you run the stock pipe before you switched the aftermarket FMF? Was told that since you can't change your jetting a pipe that changes performance can sometimes have negative effects...until you get a powercdi that is.
FYI I had a Gnarly on my 17 and feel no need for it on my 18 TPI.
I tried the stock pipe during 1H of break in riding. My feeling is that the stock pipe did not give it more low end power and torque. The TPI tractors up moderate inclines at low RPM well at steady throttle, but if you open the throttle up wanting to accelerate, or lift the front wheel to clear an obstacle it seems a bit lacking. I'm keen to improve this. Hopefully a custom ECU and a different head will improve it. Don't forget that I made many performance changes to my 2017 KTM 250 EXC, including carb (Keihin 38mm Air Striker Short + STIC metering block), SX head, FMF Gnarly pipe and VForce4 reed block) and this is my benchmark for how well a 2-stroke 250 can run. If I was comparing a totally stock 2017 to a stock 2019 TPI I'd say the TPI runs better. But who leaves their bike stock? ;-)
Why did you do all those mods, and not port the cylinder and oval bore the carb? Those 2 would give you by far the most performance.
Jon Jelen - The bike in TPI (Transfer Port Injection) which is fuel injection. As such it doesn’t have a carb (it has a throttle body and injectors). The first performance mods will be to change the head and use a custom ECU.
Tip sound as if they are struggling for air
Is this bike street legal?
Yes, street legal
In North America? I read Ktm was making a street legal 2 stroke for the states. That’s why I’m asking
Frandy Hdez - I’m in Japan. In the US different states have different regulations so you’re best checking with your local KTM dealer.
Why did u not just buy a 300??
You can't legally plate 300 2-strokes in Japan as they will not pass the stricter emission limits imposed on engine capacities over 250cc. The other reason is I like how 250s run (more responsive, faster revving and feel lighter than 300s). My 2017 KTM 250 EXC with a Keihin 38 + STIC, RK Tek head and FMF Gnarly pipe runs very strong. My 250 TPI runs pretty good now with an RK Tek head and FMF Gnarly pipe. This year I plan to fit an aftermarket ECU and see how much the performance can be further improved.
Tokyo Offroad fair play 👌🏻 I run a gnarly front and powercore 2 on my ‘19 300 which massively improved low and mid torque and the bike is much more responsive.
Gearheads. You gotta love em. Can't wait to spend another 5 grand on mods on top of what they paid for new bike. Good for the economy I guess.
The bike stock comes with no guards and no fan. IMO you can save money by fitting guards (skid plate, disk guards) and prevent damaging the engine through overheating by fitting a fan. I ride one, or two days a week, year round and consider that I get my money’s worth out of the farkles I put on my bike. Regarding engine, suspension and ergonomic mods, they are open to debate and very much come down to personal preference. Either way I enjoy modifying my bikes to suit me better and maximizing my pleasure while riding then.
Tokyo Offroad I understand. Just left a comment not looking for a fight. Sorry if I was rude.
I'd rather spend the money on parts when I first buy the bike (especially guards) than wait, damage something, not be able to ride, have to replace the part (E.g. engine case, brake disk, or radiators) and then put a guard on. I've been riding off-road for almost 40 years so have quite a bit of experience regarding how to help prevent damage to the bike. In my opinion using guards is a good idea for off-road day riding even though I know they add weight and cost money.
KTM must have got it wrong on those motors if you need to mess around with them
Michael Wall - If depends how you like your bike to run. Completely stock the power is quite mild, but does hook up well in low traction conditions. I prefer more responsive power and like how the bike runs with an FMF Gnarly pipe and RK Tek head
KTM also state against it as well..
Thats a 18
It’s a MY2019 KTM 250 EXC TPI. The 2018 Standard models had black frames (only Sixdays models had orange frames).
Why buy a 250 and have to f&@k with it to get more power ? They make 300s you know..
That's a question I get asked a lot. One reason is that you can not register new 2-stroke bikes over 250cc in Japan. The areas I like to ride require a registered bike. The second is I prefer the response and power characteristics of a well tuned 250 over a 300. Several of my friends have put 300 kits on their 250s. The low end torque increases, but the power feels flat on top compared to a 250. Personal preference...
Tokyo Offroad that's fair enough. 👍👍
Tokyo Offroad although I've had a tpi 250 and 300 and find the 300 to be a lot more responsive, have better top end legs and more torque down low as well .
P.O.D Enduro - I have no doubt that the 300 TPI rides better stock. But buying a 300 TPI isn’t an option for me (due to registration rules in Japan). Therefore I will be modifying my 250 TPI with head and ECU changes and hope to get it performing well. My 2017 KTM 250 EXC flat out rips with a Keihin 38 Air Striker Short and STIC metering block, so this is my benchmark of what a well tuned 250 should run like.