2021 KX250

BenC711
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BenC711 12/14/2020 2:35pm
12/14/2020 2:35pm
mxryan25 wrote:
I’ve heard the 2020 systems bolt right Up , however they are making pipes specifically for the 2021
They fit, but they don’t work as well as the specific 2021 pipes. They’re also solid mount not rubber mounted so it may break the subframe like the 450’s
adamw21
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adamw21 12/14/2020 2:46pm
12/14/2020 2:46pm
mxryan25 wrote:
I’ve heard the 2020 systems bolt right Up , however they are making pipes specifically for the 2021
BenC711 wrote:
They fit, but they don’t work as well as the specific 2021 pipes. They’re also solid mount not rubber mounted so it may break the subframe...
They fit, but they don’t work as well as the specific 2021 pipes. They’re also solid mount not rubber mounted so it may break the subframe like the 450’s
Any idea if ALL 21’s are rubber mounted ? Looking at buying one for the 250 but didn’t know if early made pipes were solid or not
nwmx
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nwmx 12/14/2020 4:52pm
12/14/2020 4:52pm
Where we supposed to get pipes for these things at 🤦🏻‍♂️
1
paddyB745
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paddyB745 12/14/2020 5:07pm
12/14/2020 5:07pm
I was checking RM daily for the T6 slip ons a month ago. Once I saw they were available and in stock I jumped on one, I need the sparky for the hare scrambles I race, and the stock muffler was incredibly loud and raspy for me. For what it’s worth mine is rubber mounted, so far so good, sounds insanely better than the stock muffler as well.
2

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BenC711
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BenC711 12/17/2020 2:51pm
12/17/2020 2:51pm
mxryan25 wrote:
I’ve heard the 2020 systems bolt right Up , however they are making pipes specifically for the 2021
BenC711 wrote:
They fit, but they don’t work as well as the specific 2021 pipes. They’re also solid mount not rubber mounted so it may break the subframe...
They fit, but they don’t work as well as the specific 2021 pipes. They’re also solid mount not rubber mounted so it may break the subframe like the 450’s
adamw21 wrote:
Any idea if ALL 21’s are rubber mounted ? Looking at buying one for the 250 but didn’t know if early made pipes were solid or...
Any idea if ALL 21’s are rubber mounted ? Looking at buying one for the 250 but didn’t know if early made pipes were solid or not
Yes they are all rubber mounted for the 21. There was a small batch of the 450 ones got through in 19 but PC did recall them and swap the mounts
MotoChris
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MotoChris 12/20/2020 6:02am
12/20/2020 6:02am
Is there a serviceable oil screen (not filter) that should be inspected/cleaned when changing oil like on the YZF? I don’t have a service manual yet and didn’t see it mentioned in the owner’s manual?
adamw21
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adamw21 12/20/2020 6:11am
12/20/2020 6:11am
MotoChris wrote:
Is there a serviceable oil screen (not filter) that should be inspected/cleaned when changing oil like on the YZF? I don’t have a service manual yet...
Is there a serviceable oil screen (not filter) that should be inspected/cleaned when changing oil like on the YZF? I don’t have a service manual yet and didn’t see it mentioned in the owner’s manual?
Don’t believe so or atleast I didn’t see anything in the mail or during my first oil change other then one drain bolt and the oil filter I’m sure there in a screen in the stator side that can be removed and cleaned but it’s probably a rare thing to do
MotoChris
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MotoChris 12/20/2020 6:20am
12/20/2020 6:20am
Thanks for the quick reply.
JohnMatrix
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JohnMatrix 12/20/2020 12:57pm
12/20/2020 12:57pm
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into the airbox, or considered drilling some holes on top of the airbox? May be completely worthless but wondering if anyone has played around with that yet. The airbox on this bike looks awfully tight but maybe the existing side panel inlet is more than enough.

Twisted vortex ecu on this bike is well well worth the $. The bike was pretty fast before but now it’s on another level for an otherwise stock 250f.
2
adamw21
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adamw21 12/20/2020 1:01pm
12/20/2020 1:01pm
JohnMatrix wrote:
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into...
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into the airbox, or considered drilling some holes on top of the airbox? May be completely worthless but wondering if anyone has played around with that yet. The airbox on this bike looks awfully tight but maybe the existing side panel inlet is more than enough.

Twisted vortex ecu on this bike is well well worth the $. The bike was pretty fast before but now it’s on another level for an otherwise stock 250f.
I looked at it yesterday you could get away with some holes on the right side. In concern with the box is taking filter in and out and the wash cover. They both seem to want to snag quite a bit.
1
mxryan25
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mxryan25 12/21/2020 12:04pm
12/21/2020 12:04pm
Seems as though the 250 carries the same steering stem bearing issues I’ve read about on the 450’s. I tore my bike down after the first Easy ride, greased every pivot and put 10 hours on it. Lately whenever I go in the garage my steering is basically locked in place, once free’d up it feels about normal. I think it’s partially due to the cold whether but also think these bearings are becoming contaminated rather quickly. Keep it greased up !
adamw21
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adamw21 12/21/2020 12:39pm
12/21/2020 12:39pm
mxryan25 wrote:
Seems as though the 250 carries the same steering stem bearing issues I’ve read about on the 450’s. I tore my bike down after the first...
Seems as though the 250 carries the same steering stem bearing issues I’ve read about on the 450’s. I tore my bike down after the first Easy ride, greased every pivot and put 10 hours on it. Lately whenever I go in the garage my steering is basically locked in place, once free’d up it feels about normal. I think it’s partially due to the cold whether but also think these bearings are becoming contaminated rather quickly. Keep it greased up !
Funny you say that. Because I have noticed at times coming from full lock on the stand it does seem tighter then normal
RFairbairn
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RFairbairn 12/21/2020 1:13pm
12/21/2020 1:13pm
JohnMatrix wrote:
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into...
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into the airbox, or considered drilling some holes on top of the airbox? May be completely worthless but wondering if anyone has played around with that yet. The airbox on this bike looks awfully tight but maybe the existing side panel inlet is more than enough.

Twisted vortex ecu on this bike is well well worth the $. The bike was pretty fast before but now it’s on another level for an otherwise stock 250f.
I would think Twisted would tune it based on pipe, airbox mod and fuel? Did they give recommendations? What fuel are you running?
JohnMatrix
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JohnMatrix 12/21/2020 2:17pm
12/21/2020 2:17pm Edited Date/Time 12/21/2020 2:26pm
JohnMatrix wrote:
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into...
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into the airbox, or considered drilling some holes on top of the airbox? May be completely worthless but wondering if anyone has played around with that yet. The airbox on this bike looks awfully tight but maybe the existing side panel inlet is more than enough.

Twisted vortex ecu on this bike is well well worth the $. The bike was pretty fast before but now it’s on another level for an otherwise stock 250f.
RFairbairn wrote:
I would think Twisted would tune it based on pipe, airbox mod and fuel? Did they give recommendations? What fuel are you running?
They do but you can trim fuel externally in 2.5% increments on the vortex if need be. I could probably lean it out a bit since I have the stock pipe but the bike runs so well, I don’t feel the need to change anything. If I opened up the airbox I’d probably do some plug reading and adjust fuel with the external trims. I’m running T4 in the bike. To be up front, this is a “canned” tune that was developed on another bike. My guess is that there is a bit of safety margin built in as far as fueling goes. The way I see it is that fuel will be really close regardless of minor bolt on mods. None of those mods are going to really alter the volumetric efficiency of the engine the way that cams, porting or a big bore would. On the sheet detailing the maps from twisted it says all maps are safe for T4 and some minimum octane recommendation, I forget what it was. If I threw u4.4 in the bike I’d probably add a little fuel with the external dials. This is all based on my own tuning experience, so consulting with your tuner is the best thing to do for your setup and fuel you’d like to run.
1
COAL-TRAIN
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COAL-TRAIN 12/21/2020 2:42pm
12/21/2020 2:42pm
taviobr wrote:
does anybody know if the 2020 KX 450 plastics, skid plate, and radiator braces will fit?
They will not fit
LKHill
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LKHill 12/21/2020 2:45pm
12/21/2020 2:45pm
JohnMatrix wrote:
They do but you can trim fuel externally in 2.5% increments on the vortex if need be. I could probably lean it out a bit since...
They do but you can trim fuel externally in 2.5% increments on the vortex if need be. I could probably lean it out a bit since I have the stock pipe but the bike runs so well, I don’t feel the need to change anything. If I opened up the airbox I’d probably do some plug reading and adjust fuel with the external trims. I’m running T4 in the bike. To be up front, this is a “canned” tune that was developed on another bike. My guess is that there is a bit of safety margin built in as far as fueling goes. The way I see it is that fuel will be really close regardless of minor bolt on mods. None of those mods are going to really alter the volumetric efficiency of the engine the way that cams, porting or a big bore would. On the sheet detailing the maps from twisted it says all maps are safe for T4 and some minimum octane recommendation, I forget what it was. If I threw u4.4 in the bike I’d probably add a little fuel with the external dials. This is all based on my own tuning experience, so consulting with your tuner is the best thing to do for your setup and fuel you’d like to run.
The Kawasaki tuner allows you to tune fuel 1% increments. Performance would go down hill before any safety margin was reached regardless of the tuner. When you over or under tune it changes quickly.
LKHill
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LKHill 12/21/2020 2:51pm
12/21/2020 2:51pm Edited Date/Time 12/21/2020 2:54pm
taviobr wrote:
does anybody know if the 2020 KX 450 plastics, skid plate, and radiator braces will fit?
COAL-TRAIN wrote:
They will not fit
I am certain the skid plate fits. They are the same part number.
adamw21
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adamw21 12/21/2020 2:58pm
12/21/2020 2:58pm
taviobr wrote:
does anybody know if the 2020 KX 450 plastics, skid plate, and radiator braces will fit?
COAL-TRAIN wrote:
They will not fit
They do fit my skid plate is for a 450. All the parts fit from the 450 besides engine parts. All the filters work all the plastics levers etc etc
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JohnMatrix
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JohnMatrix 12/21/2020 3:02pm
12/21/2020 3:02pm
LKHill wrote:
The Kawasaki tuner allows you to tune fuel 1% increments. Performance would go down hill before any safety margin was reached regardless of the tuner. When...
The Kawasaki tuner allows you to tune fuel 1% increments. Performance would go down hill before any safety margin was reached regardless of the tuner. When you over or under tune it changes quickly.
That’s true, I guess my point in answering RFairbain’s question which I didn’t explicitly say is...to have a perfectly optimized tune you could tell the tuner what mods you have, but unless they put the bike on the dyno and fine tune you’re going to leave some power on the table. In buying a reflash from twisted or anyone else that was developed on the dyno for another bike, I expect there is probably some safety margin built into it...and thus leaving some power on the table. That agrees with your point Smile I think we both know how the process of dyno tuning works. I’ve seen you write about it previously with intelligence, and I’ve tuned dozens of high horsepower cars. I love talking about tuning, and always up for a friendly convo. For a $250 reflash, I’m totally stoked on how the bike runs and doubt that the expense of dyno time would be worth the extra power to be had.
JohnMatrix
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JohnMatrix 12/21/2020 3:03pm
12/21/2020 3:03pm
adamw21 wrote:
They do fit my skid plate is for a 450. All the parts fit from the 450 besides engine parts. All the filters work all the...
They do fit my skid plate is for a 450. All the parts fit from the 450 besides engine parts. All the filters work all the plastics levers etc etc
Yes I saw today that Litespeed sells the same carbon skid plate for the 250 and 450
LKHill
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LKHill 12/21/2020 3:12pm
12/21/2020 3:12pm
JohnMatrix wrote:
That’s true, I guess my point in answering RFairbain’s question which I didn’t explicitly say is...to have a perfectly optimized tune you could tell the tuner...
That’s true, I guess my point in answering RFairbain’s question which I didn’t explicitly say is...to have a perfectly optimized tune you could tell the tuner what mods you have, but unless they put the bike on the dyno and fine tune you’re going to leave some power on the table. In buying a reflash from twisted or anyone else that was developed on the dyno for another bike, I expect there is probably some safety margin built into it...and thus leaving some power on the table. That agrees with your point Smile I think we both know how the process of dyno tuning works. I’ve seen you write about it previously with intelligence, and I’ve tuned dozens of high horsepower cars. I love talking about tuning, and always up for a friendly convo. For a $250 reflash, I’m totally stoked on how the bike runs and doubt that the expense of dyno time would be worth the extra power to be had.
All great points. I Express that dyno tuning and track tuning do not always correlate. Certainly when it comes to a 450 I am tuning for delivery and not absolute power, a 250F to a lesser degree.
1
nwmx
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nwmx 12/21/2020 3:14pm
12/21/2020 3:14pm
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it between that and the pc pipe. My Honda with a vortex I’ve always ran u4.4 but they are advising against that fuel so looks like T4 it is. Tokyo mods had always recommended u4.4. Never messed with the fuel trim thing I’ve always left it on 5 across the board 🤷🏼‍♂️
2
JohnMatrix
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JohnMatrix 12/21/2020 3:25pm
12/21/2020 3:25pm
nwmx wrote:
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it...
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it between that and the pc pipe. My Honda with a vortex I’ve always ran u4.4 but they are advising against that fuel so looks like T4 it is. Tokyo mods had always recommended u4.4. Never messed with the fuel trim thing I’ve always left it on 5 across the board 🤷🏼‍♂️
Rad! Make sure to report back once you try it out.
DB505
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DB505 12/21/2020 4:45pm
12/21/2020 4:45pm
nwmx wrote:
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it...
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it between that and the pc pipe. My Honda with a vortex I’ve always ran u4.4 but they are advising against that fuel so looks like T4 it is. Tokyo mods had always recommended u4.4. Never messed with the fuel trim thing I’ve always left it on 5 across the board 🤷🏼‍♂️
So is it less expensive to get the kawi tuner or the vortex?
nwmx
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nwmx 12/21/2020 5:31pm
12/21/2020 5:31pm
The kawi tuner for sure, but you won’t be able to match the power gains you’ll get with the vortex box. There’s still limitations with the stock ecu.
taviobr
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taviobr 12/21/2020 8:31pm
12/21/2020 8:31pm
just picked mine up! any tips before riding?
9
RFairbairn
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RFairbairn 12/21/2020 8:44pm
12/21/2020 8:44pm
JohnMatrix wrote:
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into...
What do you guys think about the airbox situation on this bike? Has anyone tried cutting away some of the side panel vent that goes into the airbox, or considered drilling some holes on top of the airbox? May be completely worthless but wondering if anyone has played around with that yet. The airbox on this bike looks awfully tight but maybe the existing side panel inlet is more than enough.

Twisted vortex ecu on this bike is well well worth the $. The bike was pretty fast before but now it’s on another level for an otherwise stock 250f.
RFairbairn wrote:
I would think Twisted would tune it based on pipe, airbox mod and fuel? Did they give recommendations? What fuel are you running?
JohnMatrix wrote:
They do but you can trim fuel externally in 2.5% increments on the vortex if need be. I could probably lean it out a bit since...
They do but you can trim fuel externally in 2.5% increments on the vortex if need be. I could probably lean it out a bit since I have the stock pipe but the bike runs so well, I don’t feel the need to change anything. If I opened up the airbox I’d probably do some plug reading and adjust fuel with the external trims. I’m running T4 in the bike. To be up front, this is a “canned” tune that was developed on another bike. My guess is that there is a bit of safety margin built in as far as fueling goes. The way I see it is that fuel will be really close regardless of minor bolt on mods. None of those mods are going to really alter the volumetric efficiency of the engine the way that cams, porting or a big bore would. On the sheet detailing the maps from twisted it says all maps are safe for T4 and some minimum octane recommendation, I forget what it was. If I threw u4.4 in the bike I’d probably add a little fuel with the external dials. This is all based on my own tuning experience, so consulting with your tuner is the best thing to do for your setup and fuel you’d like to run.
That makes perfect sense. I was asking because we just got a 21' and debating on what direction to go with things. For now just running 50/50 NE93 / Sun110. When pipes become available would like to either get twisted flash or Vortex from them setup and run U4.4 as that's what I run in my Yam 250f. That bike had a Vortex ECU on it and it's all setup, but I haven't messed with it. Not too familiar with this stuff as we come from a road racing background, similar but different.
I will say that side plate probably breathes really well, but is a pia when washing. atm we're just pushing some plastic in the hole to cover the filter when washing.
RFairbairn
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RFairbairn 12/21/2020 8:46pm
12/21/2020 8:46pm
nwmx wrote:
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it...
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it between that and the pc pipe. My Honda with a vortex I’ve always ran u4.4 but they are advising against that fuel so looks like T4 it is. Tokyo mods had always recommended u4.4. Never messed with the fuel trim thing I’ve always left it on 5 across the board 🤷🏼‍♂️
Did they say why they advised against U4.4?? I'm running it in my Yam250f and plan to run it in this bike after tuning. I personally prefer the lead.
RFairbairn
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RFairbairn 12/21/2020 8:56pm
12/21/2020 8:56pm
taviobr wrote:
just picked mine up! any tips before riding? [img]https://p.vitalmx.com/photos/forums/2020/12/21/467265/s1200_F4B660A1_1E81_41DF_B73E_153AD9AB310E.jpg[/img]
just picked mine up! any tips before riding?
Congrats!

Break it down and grease it and check the exhaust port.
Our had zero grease on the swingarm pivot and rear axle, front axle had a little, triples very little, swingarm bearings and rear linkage weren't too bad, but it's pretty cheap, crappy grease IMO.
Rear brake pedal was sticking on ours, backing washer had a huge burr all the way around and was binding it up, no grease on the pivot either.
Our header was bolted down crooked and ruined the copper crush seal, it had leaked from the dealer running the bike before delivery.

nwmx
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nwmx 12/22/2020 4:38am
12/22/2020 4:38am
nwmx wrote:
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it...
I ordered a vortex with twisted maps today for mine. He says they’re putting in settings keefer tested last week so I’m excited to try it between that and the pc pipe. My Honda with a vortex I’ve always ran u4.4 but they are advising against that fuel so looks like T4 it is. Tokyo mods had always recommended u4.4. Never messed with the fuel trim thing I’ve always left it on 5 across the board 🤷🏼‍♂️
RFairbairn wrote:
Did they say why they advised against U4.4?? I'm running it in my Yam250f and plan to run it in this bike after tuning. I personally...
Did they say why they advised against U4.4?? I'm running it in my Yam250f and plan to run it in this bike after tuning. I personally prefer the lead.
Dirty fuel. They said when they tear down motors thatve ran it everything’s really dirty. Tokyo mods had recommended the fuel to me for my last build. It’s harder to get T4 where I’m at
2

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