A person usually does not spend much of there time going top speed when riding an atv. Never the less it seems everyone wants to know what there top speed is. You here a lot different cliams of outragous speeds on so called stock machines such as 80 mph on a stock LTZ 400 where as the real top speed is more around 65-68 mph depending on the conditions. I have an 03 Z 400 w/ yosh pipes, jet kit, K&N, and a few other aftermarket parts. I wanted to know my top speed so I got my friend on a dirt bike with a speedometer to follow my atv on dirt roads. This is not 100% accurate but close enough. We tested on three different grades Flat, Up Hill, and Down Hill.

Heres the results:

Down Hill: 72-73 mph Up Hill: 68-69 mph Flat: 70-71 mph These numbers may be off by a few mph, but they are fairly close.
There are a few other ways to find your top speed such as GPS which is the most accurate. Or timing between two points.

What are your top speeds?

 

ive never tested my topspeed with the pipe but im guessing it should be around 70.

 

Well you could try this...

Here
Or here

 

You will notice it is always between 69-71 with the gear ratio of the Z400. I have the GPS and it said about 67-69 ish. Thats the most I could muster up with my 03 stock and my 200 lbs...

 

I hit 68 with mine when it was just piped and jetted. so 66/70 sounds about right with stock gearing
i've had mine up to 82 once and wont do it again. I now ride 45 and below, speed hurts

 

I have my gps mounted on my bars, more so, for miles traveled[img]i/expressions/face-icon-small-smile.gif[/img] Fastest I had mine up to was 58 mph. Trail was to curvy/bumpy for anything faster[img]i/expressions/face-icon-small-shocked.gif[/img]

 

I have an 05 Z and my friend just bought an 06 yfz with the full yoshi pro series pipe,jettedand all that,well we ride on the roads alot (and sand) but we passed a police radar were it reads the speed to you and the yfz only ran 74 i wasnt on mine at the time i was following him in a car. and the yfz absolutely crushes mine in a race so there is no way that stock z is running anywhere in the 70's i dont think. just my 2cents[img]i/expressions/face-icon-small-happy.gif[/img]

 

I have been clocked by multiple vehicles. On my 05 Z-400 completly stock. 113km/h, 113km/h, 115km/h, 120km/h, and 120km/h. The highest speeds are from the newest vehicles if that matters. So its probably in between there somewhere. I live at sea level and in ontario that why its Km/h.

 

A buddy of mine had his 450R clocked by radar sunday @ 73mph. I was surprised, as I expected it to be a bit faster.

 

eh, the new 450s arent known for top speed