Aluminum frame, swingarm, linkage, and steering stem off yz250f

[Gani_riders]

If all those parts were sold to you through a buddy for 500$ as a frame conversion for my yz250...

Would you do it??

I need help making this decision whether its really worth it or not. What would you guys say? The money is coming from a project bike Im selling bought it for 130$ put 50$ in and got offered 600$

[txmxer]

Is it possible to put the yz250 engine in the 250f frame? From what I can tell the geometry and way it sits would be all different with a lighter (250 2t) motor in it. It seems like with the money to make all this happen you could just get an 05+ yz 250, or one with a blown motor for cheaper. Dont get me wrong here I have no experience with this type of thing so im just throwing out ideas. Keep in mind you would have to make custom motor mounts etc.

[shrubitup]

Is it possible to put the yz250 engine in the 250f frame? From what I can tell the geometry and way it sits would be all different with a lighter (250 2t) motor in it. It seems like with the money to make all this happen you could just get an 05+ yz 250, or one with a blown motor for cheaper. Dont get me wrong here I have no experience with this type of thing so im just throwing out ideas. Keep in mind you would have to make custom motor mounts etc.

Are you sure the YZ250 motor weighs less than a YZ250F motor?

[mikeythefokker]

I think that the 250f motor finally became lighter in 2009. That's what constant R&D yields: results. I personally wouldn't spend any time putting a yz250 2stroke motor into a yz250f frame from 06-09. The aluminum yz250 frame is from the same vintage as the 06-09 yz250f frame and was actually designed to work with the 2stroke power plant. The yz 4 stroke frame is not any more advanced. I think it looks better, and that the 4stroke tank and shroud design also look a little better too. In all honesty, doing the swap would be like dumping out a bottle of bud light, only to fill it back up with miller lite. There really won't be much of a difference, and you'll be out a beer.

[RCannon]

It could be done, obviously, as the 250 into the 450 frame showed us. The cost might be high unless you can do the aluminum welding yourself. Plus, the airbox, subframe, seat, fender, etc will add to the cost. And good luck trying to sell it if you ever wanted to.

But no, its not worth it when you could get the correct frame for 500 and just switch your parts over.

[shrubitup]

I think that the 250f motor finally became lighter in 2009. That's what constant R&D yields: results. I personally wouldn't spend any time putting a yz250 2stroke motor into a yz250f frame from 06-09. The aluminum yz250 frame is from the same vintage as the 06-09 yz250f frame and was actually designed to work with the 2stroke power plant. The yz 4 stroke frame is not any more advanced. I think it looks better, and that the 4stroke tank and shroud design also look a little better too. In all honesty, doing the swap would be like dumping out a bottle of bud light, only to fill it back up with miller lite. There really won't be much of a difference, and you'll be out a beer.

Great analogy! 👍

But if he did it he could call it a YZ250AF..... .even though the stock YZ has a AF. It's a play on the other bikes trying to be AFs too.🤣

[txmxer]

Are you sure the YZ250 motor weighs less than a YZ250F motor?

Honestly im not 100% sure on that, but from what I have learned four stroke engines are generaly heavier then 2 stroke engines. If you think about it 2 strokes have less parts also, and I want to say the crank is heavier on a 4 stroke but I may just be pulling that out of my 👍

[shrubitup]

Honestly im not 100% sure on that, but from what I have learned four stroke engines are generaly heavier then 2 stroke engines. If you think about it 2 strokes have less parts also, and I want to say the crank is heavier on a 4 stroke but I may just be pulling that out of my🤣

The YZ motor hit production in 1999. The YZF came out in 2001 but they kept improving it unlike the YZ motor. What I'm saying is that the later model YZF motor may be equal in weight to a YZ motor.

I'm sorta pulling this out of my ass too but basing it on the newest KTM 250 motor which is notably smaller and more compact than a YZ motor. The YZ ought to be similar size wise to the KTM after 11 years of production. 👍

Even though the YZ motor never improved it's still very competitive and a sought after powerplant. I will say that between a 2007 YZ250F and a 2007 YZ250 - the YZ motor is wider.

[txmxer]

The YZ motor hit production in 1999. The YZF came out in 2001 but they kept improving it unlike the YZ motor. What I'm saying is that the later model YZF motor may be equal in weight to a YZ motor.

I'm sorta pulling this out of my ass too but basing it on the newest KTM 250 motor which is notably smaller and more compact than a YZ motor. The YZ ought to be similar size wise to the KTM after 11 years of production. 👍

Even though the YZ motor never improved it's still very competitive and a sought after powerplant. I will say that between a 2007 YZ250F and a 2007 YZ250 - the YZ motor is wider.

Yeah I totally get what you mean, and there is a good chance that the 250f motor weights the same. After all its been what? 9 years of constant r&d and from what Ive heard the 250f got pretty light these past few years. All the 2 strokes got was some graphics....cant complain though at least we got some upgrades in 05-06 frame wise and suspension wise. The ktm motors are somehow rediculously small, and I have to agree I love the motor on my yz.

[gscx]

if you have a 02 and up yz250 you can just use the frame and swingarm from a 05 and up and just switch the parts

[CaptDan]

If all those parts were sold to you through a buddy for 500$ as a frame conversion for my yz250...

As I understand it, the YZ250F frame makes a poor candidate for a swap because the front down tube/engine cradle junction is smack in the way of the 2-stroke motor's exhaust outlet.

The 450F frame is different in that area, making it a better choice, but still lots of work involved.

https://thumpertalk.com/forum/showthread.php?t=873589