426 more hp than 450?

[bad01300ex]

I heard the yz426 motor has got at least 20 more hp than a yfz:confused: Is this true?

[yfz450inMI]

20 more HP - that's like a 50% increase over a stock YFZ450.

More like 3-4 more hp stock is realistic. Typically the dirt bike engines are lighter which amounts to slightly better HP numbers. I know when I was looking my WR400F engine "supposedly" made 42HP vs 38HP for a stock YFZ450 quad. Remember the 04-05 YFZ450 is 439cc, not a true 450 like 2006 models, so cc difference is minimal (426cc vs 439cc).

So, you're nuts if you think 20HP more than a stock YFZ450, but a couple more HP is very realistic.

[bad01300ex]

yea thats what i thought, sounded a little off, thanks for the info

[stocktires]

Originally posted by yfz450inMI
20 more HP - that's like a 50% increase over a stock YFZ450.

More like 3-4 more hp stock is realistic. Typically the dirt bike engines are lighter which amounts to slightly better HP numbers. I know when I was looking my WR400F engine "supposedly" made 42HP vs 38HP for a stock YFZ450 quad. Remember the 04-05 YFZ450 is 439cc, not a true 450 like 2006 models, so cc difference is minimal (426cc vs 439cc).

So, you're nuts if you think 20HP more than a stock YFZ450, but a couple more HP is very realistic.


Lighter as in internal parts being lighter? Or the overall motor being lighter?

[yfz450inMI]

Rotating mass - flywheel, piston, etc.

That's why you see a lot of guys switching their YFZ450 over to YZ450F components.