03 yz450 compare to 05 06 07 08 09

Would you think that the dynos are even comparable since they were probably done years apart, and maybe even on different dynos? I'm not really concerned about wide open throttle, since I'm almost never there on the 450....I would wager to guess the 03 makes slightly more power where the 08 exhaust gives up a bunch of hp due to its restrictive design. Either way, my 03 is long gone, but I have some fond memories of shifting once per lap on that thing.
The dyno numbers I quoted are a consensus of numbers compiled from reports I've seen, so they should be representative.

The '08 exhaust is restrictive, but once that's taken care of the bike is a beast. Either the '06 or '08 can be ridden in one or two gears around a lot of MX courses, if that's your style. The '06 actually pulls better at very low revs than the '03 (I've owned both at once), and revs much harder on top. The fact is that the '03 is simply so much work to manage that it tires the rider more than the newer bikes, and the '06+ engines can and do produce better traction and lower lap times because of the lack of wasted time in wheel spin.

well i think an update may be on the cars then i like the sounds of the 3 motor in the 07 frame tho

I think Grayracer should have his own forum, with all the questions..Lol.

Here is for you. I was just thinking about the statment that work sux made. I do not beleive that 03 motor will fit an 07+ frames, without making alot of changes. Funny enough, someone just asked me if an 06 will fit an 08 or 09 frame. Again, it should, but with alot of changes. I told the person that it may be cheaper to buy a new one. Depending on what he was looking for in changing the frame..What is your opinion??

The first generation YZ450 ('03-'05) engines can be almost bolted into the aluminum frame. They require the fabrication of an upper motor mount (head stay), and possibly the fronts, but otherwise there's not much to it. However, as I mentioned, the frame carries no oil, so that has to be solved one way or other. MXA did a write up on the swap 2-3 months back.

I continue to see no advantage to putting out that much work with '06's priced so low.

All second generation engines ('06-'09) are interchangeable to the best of my knowledge, with the only difference possibly being the swing arm pivot diameter/width in the '09. This difference, if it exists, should be correctable by changing out the inserts at the rear hard point.

Well thanx every 1 for ur input appreciate it.Now sit bak and watch Reed the AUSSIE GO

Well thanx every 1 for ur input appreciate it.Now sit bak and watch Reed the AUSSIE GO

to give you the answer you desire - I have both bikes

The 03 is a monster, with a abrupt power hit, hold on for dear life feeling at speed, it feels much taller, corners like a old school bike (typically crappy) and quickly wears you out. Yes it is fast but it is a beast to stay fast on for very long. Suspension is also old school...and yes I spent a ton of $$$ to make it better and it still is no comparison

The 06 - up have more HP but they are tamer and milder especially the 08/09. The power hit is much more linear (through the entire power band), smoother and easier to go fast on for longer periods of time. The bike corners much better than a 03-05, handles better and the suspension is night and day better (no comparison)

If you want a newer bike with hit - buy a 06. The 06 has the strongest motor of all the 06-09s and bridges the power gap between the 03-05 to the newer Alum frame editions. My preference would be a 06 motor in a 09 frame.

And regarding your comment on Reed........I plan on watching Bubba eat him for breakfast lunch and dinner...with snacks in between. :thumbsup:

im not an expert on the programmable ignition topic, but a lot of the 2 stroke guys swear swapping in an ignition box or module from either the aftermarket or from an '03 YZ250 gives their newer bikes the punch they want.

Maybe there is an equivalent product for the 4 stroke world

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