Swapping on a fourstroke subframe

Well guys I got ahold of my buddies 2008 yz450f for a couple days and gave this a try. As alot of us thought, it is quite close but it is definately not a bolt on as you can see.

Using the stock upper bolt location:

0505111527b.jpg

Left hand lower mount:

0505111527c.jpg

Right hand lower mount:

0505111528a.jpg

Underneath the seat:

0505111535a.jpg

There will be a bit of fabrication involved as far as relocating the lower subframe mounts, seat mounts, and silencer mounts but this is not too big of a deal. Aluminum can easily be welded. The challenge of this swap will be the air boot and getting the seat to make a clean junction with the air box. The 2stroke seat is about an inch narrower than the 4strokes in the middle so that would need to be addressed (maybe use a combo of 2stk and 4stk seat pans and create a moddified foam as well).

Here is the seat junction:

0505111636b.jpg

Another not so much problem but something that is not the best is the right hand side panel of the fourstoke. It bulges out quite a bit to house the 4stk silencer, but if you have a shorty like myself it does look a little lost in there. Wouldn't be bad if you had a q-stealth I guess.

Left side panel:

0505111756a.jpg

Even with all these issues, this swap doesn't seem too bad. I have a 450f air box on its way from ebay and already have the f side panels and rear fender so it would just be a matter of deciding if it would be easier to moddify the fourstroke subframe to mount up and then try to build a seat to fit or if it would be easier to moddify a twostroke subframe to accept the fourstroke air box, fender, and side panels. If this can be pulled off we can go from this:

0506111135a.jpg

To something like this:

0505111636a.jpg

Did I miss something.?.?.? Why are doing this?

Did I miss something.?.?.? Why are doing this?

Why am I doing this? Because I want to :thumbsup: haha. Just trying to update the YZ in the looks department as Yamaha has failed to do so in the past decade.

sick!

Why am I doing this? Because I want to :confused: haha. Just trying to update the YZ in the looks department as Yamaha has failed to do so in the past decade.

Wasn't giving you crap.. Was just scratching my head wondering what performance/practical purpose the mod had..

Have fun tinkering.... :thumbsup:

too cold to ride up there? too much free time? jk looks like a fun project

Wasn't giving you crap.. Was just scratching my head wondering what performance/practical purpose the mod had..

Have fun tinkering.... :thumbsup:

too cold to ride up there? too much free time? jk looks like a fun project

Ha no problem branthopolis the one and only purpose of the mod would be to gain updated number plates and more notably the updated rear fender. Capt justin actually hit the nail on the head. Can you blame me for needing to have something to play with while the snow melts haha? I mean hockey season even ended earlier then planned to add fuel to the fire. Now that the snow is mostly gone though, the project will probably hit the backburner until a rainy day. After 6 months of winter without riding, any free time I have will be spent on the bike.:worthy:

It also looks like the swap could be pretty cheap too. I won a subframe with an easily fixable broken airbox tab on ebay for $14.00 and won a 450f airbox off ebay for $0.99. (yes a dollar, although the shipping will be about $20.00 ha), the side panels are a friends old set so they were free and I had already bought the fender as I was planning on trying to retrofit that. With access to a welder, that means the mod could probably be pulled off for under $100. Not too bad in my books. :confused:

Does the 4 stroke seat not fit on the 2 stroke? If it did that would probably make it a little easier

Does the 4 stroke seat not fit on the 2 stroke? If it did that would probably make it a little easier

No I gave it a shot and it would need to be about 4 inches longer to fit. It definately would make things easier though.

Sir, your 2 stroke seems to have a bit of a bulge :thumbsup:

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