top speed of YZF's

well i clocked my yz400f today on the river on the sled drag strip at 140 kph. it was a sled that clocked my speed, not the most accurate but thats the only way i could find out. so im given it about 10 kph either way. ive pretty much got stock jetting, just the jd needle and bigger main, TA pipe, twin filter, 03 exhaust cam. those are the mods just for the record. of course tires are studded up. whats the average top speed of a yz450? i plan on upgrading to one but i want a fast bike for the winter. for anyone with both blue and red experience, is there a big diff. between the 4 speed and 5 speed, power delivery and top speed.



Thats about 85mph are you sure :)

I once read somewhere that a stock 426 with stock gearing would run 86MPH. I don't know if that's true, it seems too fast.

86mph is approx 138kph.... i would think thats about right.


I had my 02 YZ426 studded last winter and only got 70mph on radar, although that was not in perfect conditions. After I geared it up a bit, I had it doing 100mph no problem. I wont run it on the ice anymore though....I gets to be hard on the bike after awhile. Towards the end of the winter I found that my clutch basket was really beat from running wide open all day. I had to replace it with a Hinson basket. 5th gear also jumped out causing the shift fork in the tranny to bend. So to fix it right I had to change 5th, 3rd and the fork. Overall it was an expensive winter. I dont know if it was a bit of bad luck or what but I wouldnt recommend running wide open on the lake all the time.

ive gotten 2 winters and a summer out mine so far, still runnen strong. like i said a sled may not be that accurate at all but i did 5 runs and they were all around 140. i even rode the guys sled ad he was on my bike because i didn't believe him the first 2 times. it was 140, 135 140 140 135. but give or take 10 kmh.

If you are running stock gearing, I would say your bike is running what it should.

With stock gearing, and assuming no tire slippage (which isn't realistic) and that each could hit the rev limit in top gear (which they can), a YZ450 and a YZ426 will both go about 88 and 94 mph, respectively. I've geared mine up two teeth, and it now has a "paper" top speed of 91.5, and I've seen 89.7 on pavement with a GPS. 140kph (86.8) is believable.

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