2003 yz450f aluminum frame conversion

I have a 2003 yz450f I was wondering if it would be possible to give it a 2006 aluminum frame? What could I keep and what would need to be changed?

Edited by Christopher McClelland

Yes, you can swap an '06 or later frame into your bike.

No, it's not worth the trouble.

For one thing, it's not any lighter, really. The '06 was one pound lighter than an '05. For another, none of your tank, seat, plastics or other bodywork will fit. Then there's the suspension, which, especially the front, is a major part of why the later bikes handle better.

One other not insignificant problem is what to do with the oil that used to go in the frame. The aluminum framed models had the feed oil storage relocated to a partitioned area in the front of the engine. Yours depends on an external tank. You could do a wet sump conversion to bypass this, but that creates other problems, like having to change oil every ride day because of the reduction in capacity.

Better to just go buy an '06 or '07 and ride it with all the good stuff already in place. You can get one for under $2500 these days pretty easily.

I agree with grayracer. What are you trying to gain by swapping to an aluminum frame? I actually prefer steel frames as they are easier to repair and easier to work on due to less frame material being in the way of accessing other things such as the carb etc.

Edited by woods-rider

I actually prefer steel frames

Ride an '03 YZ450 and then jump on an '06 or '08. You'll get over it.

I change my oil every ten hours. its bellray semi synthetic. So your saying that the newer aluminum framed models have to have the oil changed more often? IF I did a wet sump conversion it would have the same capacity as the newer motors right?

I payed 2400 for my bike this last fall. Its got upgraded shocks front and back, Aluminum Radiator guardes, Skid plate, FMF Titanium 4 muffler, Powerbomb, and the vavles were just done before I bought it. The bike starts 1st kick everytime.

Ive noticed that you can hear the valves there really noisy when Idling. When you kill the bike you can here the valves it sounds like they come to a ruff stop.

Also I tried going up a small trail and kept stalling it. Then it wouldnt stop stalling because my clutch wouldnt disengage. I think its because you cant go slow on these bikes and I slightly warped my clutches? I ajusted the cable and it works fine but if I get stuck and keep stalling in a certain area I have to ajust the cable again.

Edited by Christopher McClelland

Ride an '03 YZ450 and then jump on an '06 or '08. You'll get over it.

I have ridden '09 WR450s (same as my '06, just with AL frames) and didn't notice any handling differences. I have also worked on the '09s and they are a PITA compared to my '06.

IF I did a wet sump conversion it would have the same capacity as the newer motors right?

Wrong. The new motors have extra oil capacity built into the motor.

I have ridden '09 WR450s (same as my '06, just with AL frames) and didn't notice any handling differences. I have also worked on the '09s and they are a PITA compared to my '06.

I didn't mention the WR, nor did the OP.

So your saying that the newer aluminum framed models have to have the oil changed more often? IF I did a wet sump conversion it would have the same capacity as the newer motors right?

No, and no. The aluminum framed models have nearly as much capacity as the steel framed bikes, and even though the feed oil is carried within the engine assembly, they are still dry sump oiling systems. With the wet sump conversion, you end up with about half the oil capacity, so it gets beat up exponentially faster.

I didn't mention the WR, nor did the OP.

Working on the AL frame bikes still applies regardless of the model. ALL aluminum frame bikes have more material in the frame making it more difficult to get to the engine, carb etc. Not saying that they are not as good as steel frames, just saying it wouldn't be worth the engine swap.

I would still like an answer as to what it would take to do the swap? I don't want six opinions on whether or not I should do it I wanna know how much work it would be, no disrespect to anyone but any information would be appreciated

I would still like an answer as to what it would take to do the swap? I don't want six opinions on whether or not I should do it I wanna know how much work it would be, no disrespect to anyone but any information would be appreciated

Dry sump your motor and stick it in an 07 frame, better than 06.

It is a dry sump. The problem is that there's no tank in the aluminum frame, so you have to add one, or make it a wet sump, and wet sump kits cannot be recommended.

MX Action did a complete writeup on just this kind of swap once about 2 years ago. You might try searching their back issues. It's not terribly difficult to get the engine into the frame, but it does require mount point modifications.

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