250f in a YFZ 450 frame

[Hollywoodracing]

Anybody know where the link to it is... I know someone on here said they saw it, or knew someone who did it...
Thinking about building one....

[Hollywoodracing]

Wow, nobody ever considered this swap? I figured it would be good for some of the young riders that are on the tall side...

[born2ride14]

i know a kid that has a crf250r motor in a yfz and another kid has one in a blaster, and my buddy mildtowildracing has a wr250f motor in his blaster, as long as you and chop cut and weld, it should be able to be done

[Hollywoodracing]

Originally posted by 300maniac
i know a kid that has a crf250r motor in a yfz and another kid has one in a blaster, and my buddy mildtowildracing has a wr250f motor in his blaster, as long as you and chop cut and weld, it should be able to be done

I agree with the chop and weld thing.... but....
I'm looking for someone who has done this swap.

I know about the blaster thing, I've heard about the crf250r thing. I have a full race National Pro YFZ.. I want to put a 250f in it for my daughter... Sooooo, I want to see it first and find out how easy it is. I think it should be very easy....... Almost the same motor.. Almost.......

[mildtowildracin]

well the hardest part is trying to ballace it right. and the swing arm. in my blaster with the 250f we madified the back of the quad to accept a banshee swing arm and then we madified the swing arm more to run with no linkage and made the motor fit into the swinger like the stock blaster motor did. our nxt 250f is gonna be my motor in a kfx450 frame unless i can sell my bike for a resonable amount so i can afford to build annother motor to the same extent this one is in. :devil:

[mildtowildracin]

ohh and 300manaic (jesse) you forgot about camerons crf250f in the blaster frame 2

[mamafite]

I think I can help you with this,if you switch to a yz250f or a wr250f your fabrication problems would be very small.Also the new Apex 250 is basically a Lonestar YFZ450 with a 2007 yz250f.If you have any questions feel free to email.

Troy Fite

[Derrick Adams]

You mean something like this?

http://i92.photobucket.com/albums/l34/Derrick_Adams/yz250fquad.jpg


I found that pic in the "let's see those hybrids" thread.

This engine swap will be extremely easy to do, IMO. The sprocket shaft in the transmission is narrower, as well as the cases. So you will end up moving the engine to the left to line up the sprockets. Other than that, should just be mounts.

My suggestion would be to look into some of the narrower MX tires that ITP is making now for the small engined bikes too. Probably help a bunch in acceleration.

[national #9]

go to kidsonquads.com, the custom quads 90 mods page, they build them with suzuki or yamaha motors in them.

[gb_proshark]

here in the uk the 250 hybrids are very popular they have their own class, heres a couple of pics

[gb_proshark]

another 250

[gb_proshark]

250

[Hollywoodracing]

Originally posted by gb_proshark
here in the uk the 250 hybrids are very popular they have their own class, heres a couple of pics
WOW!!! That is cool!!! How hard is the swap to put the 250F into the yfz frame?

[gb_proshark]

well most are tuned engines i.e willpower racing.etc but most are built by big uk quad companies like atv world, not sure how hard they are to build, just need to know what you are doing

[Hollywoodracing]

Originally posted by gb_proshark
well most are tuned engines i.e willpower racing.etc but most are built by big uk quad companies like atv world, not sure how hard they are to build, just need to know what you are doing I agree, Not worried about building it though.. Just gathering information to make it easier..:D :D
I understand that the rear mount is the same, so the swingarm pivot is the same. But, if the countershaft sprocket is set closer to the center of the frame than a 450 then somehow the countershaft needs to be extended or some sort of spacer needs to be added so it aligns with the rear sprocket... hmmm more stuff to ponder....