The June 1988 3&4 wheel action did radar tests with all the 2-stroke performance quads of the day. The 250's (250R, LT250 and Tecate) were between 72 mph and 74 mph. The Banshee was 77 mph and the LT500 was 79 mph. Please keep in mind these were stock machines.

I've checked my 250R just by driving beside a car and it agrees with these numbers (it is right around 73 mph).

Anyway, my question is has anyone checked the top speed of the new 450's? I noticed the last dirt wheels mentioned both top out at over 80 mph. This I find hard to believe.

I run alot of roads and a faster road speed would be nice.

Thanks in advance.

 

i have that same issue! thats when they went to the dragstip in 1988. back then there seemed to be alot less BS in the mags. I know the old ATVSPORT would always list the top speed of the bikes.

i saw that 80mph thing about the newer bikes as well. It does seem unbelievable but my 450R can pass a raptor so it may not be that far off; 4wheel action did a test a couple years ago with top speeds and it had the banshee @ 77, raptor @ 76... they need to do another test.

the cpsc has the limit for OEMs set at 75. but that is subjective to altitude, temp, a good bike (where you have 2 stock models and 1 ALWAYS outperforms the others) and crazy @ss riders.

 

I wish they would do standard acceleration and top-speed tests on all new ATV's on ashphalt. This would eliminate many variables (tires and soil conditions) and at least give a stock comparison from machine to machine.

It would also be nice if they dynoed every machine they tested

 

my buddy owns a yfz with a hmf slip on and open airbox and cam mod and horrible jetting and stock gearing and it hit 73 on the dyno at 36 hp....and when i dynoed my raptor with the kenz 727 and stock gearing it did 63 in 3rd i didnt get to do an all gear but i bet its around 75-78mph

 

Mathematically a YFZ will have a top speed of 76 miles per hour at 10 000 RPM with stock gearing and stock tires. It needs an exhaust, cam mod, jetted correctly, no airbox lid to make max HP at 10 000 RPM. A YFZ getting 11 000 RPM, that’s just before RPM limit will produce 83.5 miles per hour. A stock YFZ will produce max HP at around 8500 RPM. At that RPM max speed is around 64.5 miles per hour.

It's not the fastest quad around. I have no idea what a 450r will produce

Stock DS or Raptor will kill a stock YFZ on top speed. A stock raptor has a mathematical top speed of 71.2 miles per hour at 6300 RPM. A modified stock geared raptor with 20" tires will produce 79.1 miles per hour at 7000 RPM. A well tuned raptor can get up to 8000 RPM in 5th, giving it a top speed of 87 plus miles per hour.

 

We put GPS in out pocket and ran on a dry lake bed near the Bonneville Salt Flats.
I have a 450R, but was geared down (one tooth on the back), I reached 74.5mph
My buddy got to 79 on his stock geared YFZ.
That was at 4800 feet.

 

KGB, can you tell us what mods the 450r and YFZ have?

The one tooth smaller on your back sprocket would give you about 1 to 2 miles per hour more than a stock geared 450r, but it will depend on what power you have and what RPM you can get to in 5th gear. The more power you have, the easier it is to get to the higher RPM ranges in 5th gear.

If you can get the 450r primary, secondary and 5th gear ratio's I will be able to tell you what actual speed you can do, or what RPM you are doing at a set speed.

You friends YFZ450 is revving close to max RPM to get that speed.