What is a top speed for a stock 400ex?

 

A friend followed behind a vehicle on his 400EX. His quad isn't all stock though. It has a White Brothers E-Series slip-on, and a K&N filter. His top speed on the pavement was 69-70. I would say with a totally stock machine, you'd be able to run about 68 mph or so. Hope I helped.

 

I wish the 400EX would do 68mph. Unfortuneately, I think you buddies speedo is out of whack. The stock gearing and rev limiter will only let it go about 60mph, unless you push it off a big cliff.

 

Maybe not, but you have to realize the elevation differences. This will affect how the machine performs if it isn't jetted to meet your elevation and mods properly. I do know that my Honda 300 2WD would go about 55 mph on pavement, so around here, I think that + or - 68 mph is a somewhat safe bet.

 

I am hoping to take my GPS and hook it up to a friends 400EX to answer this question. The EX is totally stock and I would be very suprised if it was higher than 65. You can guess all you want about top speeds but I dont believe anything unless it comes from a Radar gun or GPS.

 

elevation makes a WORLD of difference in the readings because of the jetting (air feul mixture)
the higher up you go the harder it is for man and machine to breathe.

 

I didn't think that the White Bros. slip-on, and K&N filter would make more than 1 mph or so difference. Maybe it did. Please tell us your results with the GPS run.

 

max400ex, you're right about the elevation; you do lose a lot of power. General rule of thumb is about 2% to 3% per 1000 feet.

I think one thing that helps out is since the air is thinner you have less wind resistance too. I'm not sure if it balances each other out but I've never had trouble reaching tops speeds that are comparable to people at sea level. I recently clocked my Banshee at 82 MPH at 6900 feet (pics on my web site to "prove" it under Banshee Photos) and my Acura CL Type S at 145 MPH at around 6000 feet. naturally you have to be jetted correctly for it.

 

How much did you pay for that GPS and where did you get it?

 

It depends on how you ask.I think it's some where between 35mph and 90mph.