I went out with the GPS today to see what my 400EX would do on top-end and i got 73.8 mph. This was with stock gearing and i was bouncing off the rev-limiter quite easily so i let off. This was also with my stock carb. I have a Lectron(which gives it even more pop)for it, but didn't have it on(long story). I think that if i put on a 16 tooth front sprocket, and get my Lectron carb back on, i should be able to hit 80 mph. I have a DMC full exhaust, K@N filter with lid removed, 11:1 lightened Ross racing piston(stock bore)with an XR 400 head gasket(thinner) total 11.25:1 compression, Web-Cam 450/451 grind cam, and the Lectron carb( that wasn't on at the time). What are all you other guys getting for top speed on radar or GPS on your modified 400EX's?

 

That seems alittle high to me.

 

Good luck with this thread GrimReaper. We started one a few weeks ago and a bunch of guys with Recons and Raptors called us liars and made up stories of "if it was falling off a cliff", "on a trailer going down the highway". You are at the max of the gearing and CDI rev limiter. Mine does the same thing. A carb and aftermarket CDI box will pull more.

 

Well, i wasn't asking what you thought. What are you saying, that my GPS is lying or off? i am just stating what my GPS said and was asking other 400EX owners what they were getting out of their modded quads.

 

that sounds right grimm. if you have a 2000 checkt he throttle at the carb and where it connects to the thumb Honda flubbed up i made a post asking about taht and a guy said his carb opened only 80%


P.S. GPS doesnt lie

 

I have a supertrapp, K&N,3" hole in the air box and realtors and the max speed was only 61.1 mph and the Gps Was aquired within 23ft I was really mad so I changed the jet to a 160 main and pump up the tires then see how that works. Hopefully I will get up around 65-67.

P.S. If someone thinks i am lying they can bring their unreliable form of tracking speed. I should be able to gain 5 mph just by having that...

 

Grimreaper,
It seems that SKYQUADRIDER is a 400ex owner.

 

I was clocked at 67 on a piped 400ex I had. Considering yours has more mods, 73.8 mph seems realistic.
Where did you get your Ross piston, and if you don't mind, how much was it?

 

Gary, I got the piston from C.T. Racing for $125. It is a very high quality piston, Allen at C.T. said that they run the Ross pistons in their full race bikes. It was the best mod that i did so far.

 

Ericsraptor, what is your point? I wasn't bashing him. I clearly stated a question asking "what top speeds others were getting with their mods", not "do you guys believe my top speed".