75 your ***. 400EX are not even close to that

 

going 72 would make it faster than a banshee, raptor, and a ds650. msybe it would go that fast if it was a 2 stroke.

also are u sure u lost the 10mph cuz of your elevation? or was it impropper jetting, or just the sand stealing your speed?

 

He forgot to say he had 75mph tail wind.

 

Hey guys~

About a month ago, there were speed runs at the lake by my house. They had the radar gun reading at about 1300', or 1/4 mile. Stock 400ex w/o studded tires managed 55.6 mph. 440ex w/ studded 20" tires managed about 58 mph. 440ex w/ studded 22" tires managed 63 mph. My 400 scrambler went 56.4 mph and there was no more speed to be gained. A DS650 hit 75 mph! Now, are you going to tell me the radar gun had to have been reading slow? If that's true, the pro-mod drag sled that hit 137 mph must have really hit 160mph! I don't think so!! The radar gun was accurate. The 440ex's had it tapped out in 5th gear, but it wasn't hitting the rev-limiter yet. All machines had stock gearing also.

 

Temperature and elevation are factors too. I don't doubt that everyone else got the reading that you did, but I honostly can go 72, before the 416 mods I've recently done. I'm right about at sea level too, so maybe that is one of the differences too. I don't know the exact reason why everyone gets different reading, but it has to do with the machine variances and location/weather differences. I've checked it with radar and numerous different vehicles too. All I have to say is, I'm sure everyone is telling the truth about the readings they got and I am too. My 400 will go 72, but other machines that you are mentioning go faster than 72 HERE. Don't forget that I say here, because they aren't going to go as fast where you live obviously. Anyway, it's something to think about.

 

Good points there Steven. I too am not sure why/how speeds can vary as much as 15 mph for the same machine! Having a machine on pavement could easily add 5 or more mph because it takes less effort to move the machine. That's why sand requires mucho horsepower to go fast. Simple things like adjusting the air screw can affect speeds as well. Polaris recomends in the owner's manual to adjust the air screw everyday! There are many factors that affect top speed and all the speeds stated are very, truly possible.

 

Glad to see there are some thinkers out there. I did not say my stock 400 did 75. In fact stock it would only run 65, pulled the air box and jetted it went up to 70. Dropped in a TC Racing 426 MX race motor with Lectron carb and gained 5 more. The built Banshee's I run with are all worked and pull over 80 with those blasted 6 gears! Don't be such haters/disbelievers guys.

 

When I was just reading the new posts I remembered one other factor in top speed. When I had my 300EX a few years ago, I changed the oil in it one day and put 20W-50 back in. When I checked the top speed of it, it went down about 5 mph!! I was so upset!! I could even hear that it wasn't revving out as far as it use to. Then I thought the oil might be doing it, so I went home and put 10w30 back in and it gave the 5 mph back!! Little things that you don't think about might have a big effect. I have done a lot of top speed checking and trying to figure out how to gain more because where I live, it is one of the most important things. I've also heard that the way that you break in your atv will effect the power of it too. I don't know if it's true, but my uncle's and my fourwheelers were broke in wide open from the minute we got them. We don't wait to open them up. As soon as they come of the back of the truck for the first time, they go wide open. I don't know if that effects anything, but it's something else to think about.