RedMoto Crf400 kit

Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a worn or damaged cylinder on your bike already. I know it would obviosly be a cheaper and more direct route to go with an Austrian 350cc bike. I only ride moto and really enjoy the mid size platform, and it seems like there is a common thought that the CRF450 is on the agressive side in the power department. When I came across the kit I couldnt help but think this would be a really cool bike, built with a properly tuned Vortex by XPR or Twisted it could be great, or atleast in my head it seems that way. The general feedback from riders is that the CRF250 handles much better then the 450 in stock trim, in the same/very simiar chassis. A little less torque/more free powerband could help with the handling and make the bike less tiring to ride? 

 

https://www.redmotousa.com/product-page/400rx-engine-kit

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mvd61
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Brandon, SD, USA
10/29/2023 10:42am
Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a...

Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a worn or damaged cylinder on your bike already. I know it would obviosly be a cheaper and more direct route to go with an Austrian 350cc bike. I only ride moto and really enjoy the mid size platform, and it seems like there is a common thought that the CRF450 is on the agressive side in the power department. When I came across the kit I couldnt help but think this would be a really cool bike, built with a properly tuned Vortex by XPR or Twisted it could be great, or atleast in my head it seems that way. The general feedback from riders is that the CRF250 handles much better then the 450 in stock trim, in the same/very simiar chassis. A little less torque/more free powerband could help with the handling and make the bike less tiring to ride? 

 

https://www.redmotousa.com/product-page/400rx-engine-kit

I’ve had the 400 on a 21’ 450rx. It was great. Still had plenty for Colorado mountains too. I also have a 23’ 250 with their 300 kit. It’s really good as well. 

BigRedMachine
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Grants Pass, OR, USA
10/29/2023 10:56am

Seems sacreligious to change the cc.s on a crf450 to try and make it a manageable trail bike.   I’m sure XPR has a map on their vortex that would soften the powerband of a crf450 for just such a thing.   My Ktm 350 has a yank your arms out of you shoulders map and a super mellow map that with traction control on makes the bike feel like a honda xr200.   Hate that map as it’s super boring, but if that’s your thing, it’s there if you want it. 

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cloverdale
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Zionsville, IN, USA
10/29/2023 11:09am Edited Date/Time 10/29/2023 11:09am
Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a...

Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a worn or damaged cylinder on your bike already. I know it would obviosly be a cheaper and more direct route to go with an Austrian 350cc bike. I only ride moto and really enjoy the mid size platform, and it seems like there is a common thought that the CRF450 is on the agressive side in the power department. When I came across the kit I couldnt help but think this would be a really cool bike, built with a properly tuned Vortex by XPR or Twisted it could be great, or atleast in my head it seems that way. The general feedback from riders is that the CRF250 handles much better then the 450 in stock trim, in the same/very simiar chassis. A little less torque/more free powerband could help with the handling and make the bike less tiring to ride? 

 

https://www.redmotousa.com/product-page/400rx-engine-kit

mvd61 wrote:
I’ve had the 400 on a 21’ 450rx. It was great. Still had plenty for Colorado mountains too. I also have a 23’ 250 with their...

I’ve had the 400 on a 21’ 450rx. It was great. Still had plenty for Colorado mountains too. I also have a 23’ 250 with their 300 kit. It’s really good as well. 

I agree a 100%. If you do not want to buy an Austrian bike this is the best purchase you can make to improve lap times (both in the woods and the track). Even the Factory backed GNCC  Austrian riders (Orange, Red and White versions) choose to ride the 350 vs the 450. If it works better for the most elite off road riders in America, than statistically it would really be an awesome improvement for us mortals. A no brainer....

1
motomind132
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Chicago, IL, USA
10/29/2023 11:27am

How do they account for the larger head space is what wonder. With a bigger piston you can shape it a touch.  Can you close up these heads at all with the valve layouts?

The Shop

Tumic
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10/29/2023 12:37pm

I have it on my bike but i have not ridden it as a 450 for comparision.

BUT, it still feels like a small 450, when you ride a KTHUSGAS 350 they feel like a big 250, so this is just a little mellower version of a 450.

next bike will be a 250 with a 300 kit instead of a 450 with a 400 (413cc) kit.

2
cloverdale
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Zionsville, IN, USA
10/29/2023 1:00pm
Tumic wrote:
I have it on my bike but i have not ridden it as a 450 for comparision. BUT, it still feels like a small 450, when...

I have it on my bike but i have not ridden it as a 450 for comparision.

BUT, it still feels like a small 450, when you ride a KTHUSGAS 350 they feel like a big 250, so this is just a little mellower version of a 450.

next bike will be a 250 with a 300 kit instead of a 450 with a 400 (413cc) kit.

I am interested relative to the Athena 300 kit. I have punched out a Kaw 300, a Honda 250 and Yamaha 250 for stroke. I regretted all three projects because I lost so much over rev. That being said, the tunable Vortex was not available at that time.

Lightning78
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Huntington Beach, CA, USA
10/29/2023 1:15pm

I had an 07 crf250 that I put an Athena 280cc kit on and compensated by adding a top end focused hotcam. The bike was amazing and had a BROAD spread of power. I loved that bike till it Honda bogged me on the face of a big double at Perris and nearly killed me

Greenbush
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Location
Saint Johns, MI, USA
11/5/2023 11:50am

Not to hi jack this thread but I’ve got a 22 crf 250 with the Athena 290 kit for sale if anyone is interested 

 

3
5/27/2024 7:19pm
Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a...

Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a worn or damaged cylinder on your bike already. I know it would obviosly be a cheaper and more direct route to go with an Austrian 350cc bike. I only ride moto and really enjoy the mid size platform, and it seems like there is a common thought that the CRF450 is on the agressive side in the power department. When I came across the kit I couldnt help but think this would be a really cool bike, built with a properly tuned Vortex by XPR or Twisted it could be great, or atleast in my head it seems that way. The general feedback from riders is that the CRF250 handles much better then the 450 in stock trim, in the same/very simiar chassis. A little less torque/more free powerband could help with the handling and make the bike less tiring to ride? 

 

https://www.redmotousa.com/product-page/400rx-engine-kit

Have you tried it yet?

I love my Hondas and i'm trying not to buy an orange bike. 

Currenly my 21 450RX is just too hot and aggressive for tight woods, the 300s tractor through narly terrain while 450s are on the clutch trying to not stall. The kit on thier website claims it improves on woods trails. 

 

Don't say buy a 2 stroke, i want to keep this bike, to sell now and lose money on a 300 is not my cup of tea.

mvd61
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Location
Brandon, SD, USA
5/30/2024 6:46pm
Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a...

Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a worn or damaged cylinder on your bike already. I know it would obviosly be a cheaper and more direct route to go with an Austrian 350cc bike. I only ride moto and really enjoy the mid size platform, and it seems like there is a common thought that the CRF450 is on the agressive side in the power department. When I came across the kit I couldnt help but think this would be a really cool bike, built with a properly tuned Vortex by XPR or Twisted it could be great, or atleast in my head it seems that way. The general feedback from riders is that the CRF250 handles much better then the 450 in stock trim, in the same/very simiar chassis. A little less torque/more free powerband could help with the handling and make the bike less tiring to ride? 

 

https://www.redmotousa.com/product-page/400rx-engine-kit

Have you tried it yet? I love my Hondas and i'm trying not to buy an orange bike.  Currenly my 21 450RX is just too hot...

Have you tried it yet?

I love my Hondas and i'm trying not to buy an orange bike. 

Currenly my 21 450RX is just too hot and aggressive for tight woods, the 300s tractor through narly terrain while 450s are on the clutch trying to not stall. The kit on thier website claims it improves on woods trails. 

 

Don't say buy a 2 stroke, i want to keep this bike, to sell now and lose money on a 300 is not my cup of tea.

You won’t be disappointed with the 400 kit from RedMoto. They have it dialed. 

smv ryder
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Location
Aspen, CO, USA
5/30/2024 7:52pm

My buddy has an amazing Redmoto CRF 400 for sale in Colorado 

burn1986
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12246
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4/16/2010
Location
bossier city, LA, USA
5/30/2024 10:22pm Edited Date/Time 5/30/2024 10:25pm
Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a...

Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a worn or damaged cylinder on your bike already. I know it would obviosly be a cheaper and more direct route to go with an Austrian 350cc bike. I only ride moto and really enjoy the mid size platform, and it seems like there is a common thought that the CRF450 is on the agressive side in the power department. When I came across the kit I couldnt help but think this would be a really cool bike, built with a properly tuned Vortex by XPR or Twisted it could be great, or atleast in my head it seems that way. The general feedback from riders is that the CRF250 handles much better then the 450 in stock trim, in the same/very simiar chassis. A little less torque/more free powerband could help with the handling and make the bike less tiring to ride? 

 

https://www.redmotousa.com/product-page/400rx-engine-kit

That has got to be the coolest idea I’ve seen in awhile. Wow. Who would’ve thought to go down in displacement? Everyone has stated they would buy a CRF, KX, YZF 350 in a heartbeat. Hmm. Cool I guess that begs the question “Could you make a 350 that would compete with the Austrian 350s?”

burn1986
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Location
bossier city, LA, USA
5/30/2024 10:30pm
Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a...

Has anyone had any experience with the 400cc kit from RedMoto? Cost wise it isnt crazy, and would make even more sense if you had a worn or damaged cylinder on your bike already. I know it would obviosly be a cheaper and more direct route to go with an Austrian 350cc bike. I only ride moto and really enjoy the mid size platform, and it seems like there is a common thought that the CRF450 is on the agressive side in the power department. When I came across the kit I couldnt help but think this would be a really cool bike, built with a properly tuned Vortex by XPR or Twisted it could be great, or atleast in my head it seems that way. The general feedback from riders is that the CRF250 handles much better then the 450 in stock trim, in the same/very simiar chassis. A little less torque/more free powerband could help with the handling and make the bike less tiring to ride? 

 

https://www.redmotousa.com/product-page/400rx-engine-kit

You can search the web for some others who have done it. Here’s a reply from another site

BoxcarWilly

Posted February 22, 2023

 My Rides (12)

The 400RX kit is so badass. Make the lurch-y torque-y CRF450 actually rideable. So smooth. I could ride it all day. 

If you have the money and ride red off-road it's a no brainer. 

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