i read in dirt wheel they r using a longer stroke soo wont that effect the fast revving we all loved about the yfz 4-stroker revving lik a 2-stroke? i no they upped it to a true 450 but wont it effect what we had all come to love

 

I don't think your really going to notice the longer stroke. The 05 was 62mm and the 06 is 63.4. But what I think you will notice is the lower compression. The 05 was 11.9:1 and the 06 is 11.4:1. I think you will notice that more.