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Honda Cr125 piston swap

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I've heard of people swapping pistons from the 2 stroke sportbike Honda RS (not sure from the RS125 or RS250) to a Honda CR125 motor.......... and was wondering what are the advantages?  RS250 is a twin cylinder so divide that in half 125cc each cylinder making the piston fit.

 

BTW, I plan to get either a Honda RS250 or the Honda NSR250 in the future and ride it on public roads and make you all jealous.  Thanks.  :ride:

Edited by Honda_Power

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I've heard of people swapping pistons from the 2 stroke sportbike Honda RS (not sure from the RS125 or RS250) to a Honda CR125 motor.......... and was wondering what are the advantages?  RS250 is a twin cylinder so divide that in half 125cc each cylinder making the piston fit.

 

BTW, I plan to get either a Honda RS250 or the Honda NSR250 in the future and ride it on public roads and make you all jealous.  Thanks.  :ride:

 

Yes, divide it in half, that accounts for any and all bore x stroke differences.......Where did you hear of these things? And what's the point? Just go to wiseco and pick up a top end kit for 120 bucks and call it a day.

 

P.S. A 250 streetbike doesn't make anyone jealous, except maybe beginner women street riders......

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Yep just get the weisco kit and be done, dont frankenstein the bike.

I had a nsr150, cool little street bike. Wished i hadnt sold it.

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Yes, divide it in half, that accounts for any and all bore x stroke differences.......Where did you hear of these things? And what's the point? Just go to wiseco and pick up a top end kit for 120 bucks and call it a day.

 

P.S. A 250 streetbike doesn't make anyone jealous, except maybe beginner women street riders......

 

Actually, in the case of the race replicas it does...... :smirk:

 

And why wouldn't it, they can still out brake and out corner a modern 600.

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The major advantage of the RS 250 piston in the CR 125 is that it raises the compression ratio to 40:1 to match your premix ratio. With your premix and compression ratio's perfectly aligned, do the CR 125 six speed swap and find a long straight road. As soon as you kick it in sixth gear and hit 88 MPH, the CR's built in flux capacitor will kick in and send you to back to 1955. This only will work when your premix ratio, compression ratio, and the planets are perfectly aligned. That's really the only advantage of the RS piston swap. Not worth it to me. 

 

This is too much fun.

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The major advantage of the RS 250 piston in the CR 125 is that it raises the compression ratio to 40:1 to match your premix ratio. With your premix and compression ratio's perfectly aligned, do the CR 125 six speed swap and find a long straight road. As soon as you kick it in sixth gear and hit 88 MPH, the CR's built in flux capacitor will kick in and send you to back to 1955. This only will work when your premix ratio, compression ratio, and the planets are perfectly aligned. That's really the only advantage of the RS piston swap. Not worth it to me. 

 

This is too much fun.

 

How bout 1:1 final gearing too, 40 tooth on the back and front? so the gearing ratio adds to the premix and compression ratio and time travel is 36.632 % more efficient?

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How bout 1:1 final gearing too, 40 tooth on the back and front? so the gearing ratio adds to the premix and compression ratio and time travel is 36.632 % more efficient?

I didn't think about it earlier, but that makes a lot of sense. That would probably speed up the time travel process as well as making the flux capacitor run cooler. That could be a major problem solver as flux capacitors have the uncanny tendency to overhead and leave you stranded, especially the ones produced by honda. Edited by KTMforlife

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I didn't think about it earlier, but that makes a lot of sense. That would probably speed up the time travel process as well as making the flux capacitor run cooler. That could be a major problem solver as flux capacitors have the uncanny tendency to overhead and leave you stranded, especially the ones produced by honda.

 

I thought a flux capacitor worked better when hot?

 

 

Note to all: I've found where this guy gets kooky ideas from.

 

He's been reading a kart forum where they use NSR honda v twins and CR125 engines. They Frankenstein the NSRs with KX and CR parts because parts are hard to get for the NSR.

 

The kart guys are impressed particularly the longevity of a standard CR125 engine.... haha compared to built kart engines I wonder why? :lol:

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Only reason to have a sportbike is for fast highway runs durrrrr, 250 aint good for that

 

Comparing an NSR250 to a Ninja 250 is like comparing a YZ125 to a TTR 125 and saying "well they're both 125s".

 

Watch from 11:20 onwards if you don't think a two stroke 250 can hold its own against 600s, especially considering that there's not a huge amount of shame in killing people in corners and having them make up time on you in the straights....

 

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Comparing an NSR250 to a Ninja 250 is like comparing a YZ125 to a TTR 125 and saying "well they're both 125s".

 

Watch from 11:20 onwards if you don't think a two stroke 250 can hold its own against 600s, especially considering that there's not a huge amount of shame in killing people in corners and having them make up time on you in the straights....

 

 

If you aint spotted the trolling yet then you're gonna have a bad time

 

Edit: Sportbikes, lame. 

Edited by Fade

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If you aint spotted the trolling yet then you're gonna have a bad time

 

Edit: Sportbikes, lame. 

 

Edit: Never mind, I can't fathom not liking a several forms of riding.

 

Each to their own, I'll just assume your a flatbiller.

Edited by BushPig

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I've heard of people swapping pistons from the 2 stroke sportbike Honda RS (not sure from the RS125 or RS250) to a Honda CR125 motor.......... and was wondering what are the advantages?  RS250 is a twin cylinder so divide that in half 125cc each cylinder making the piston fit.

 

BTW, I plan to get either a Honda RS250 or the Honda NSR250 in the future and ride it on public roads and make you all jealous.  Thanks.  :ride:

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