How to get more throttle response on my 400ex i gotta lex exhaust and it seems like its more motor than go but idk should i take the silencer out or wut can i do it bogs for a split second.

 

Did you rejet for the lexx slip on? If not thats probably why its bogs. If you want it to rev out faster and dont want a project just throw a new plug and uni air filter on her. If you want a project you can pull the fly wheel and have it shaved. But if you do you will lose the ability to really lugg down on the trails.
What do you think about the lexx pipe?

 

Not sure if they make them for the 400's but i know guys who have Boysen quick shots on their 450's there supposed to improve throttle response. Something to check into.

 

A silencer alone wont do jack **** but make your bike loud. You need headers and a jet kit. If your looking for more low end torgue(snap) get a smaller front sprocket.

 

Also the split second bog is normal at lower rpm's. If your motor is revved it wont be as noticeable try to stay higher in your gear then as to lower. I sense your misjudging on lack of familiarity with the ex. Could be wrong!

 

This is a two week old thread but, maybe you'll check back in with recent posts.

You do need to rejet If you haven't. You shouldn't have even sit on the thing without doing it. It can damage the quad. The kit is not necessary. Save the money and just get the jet. Unlike 2-stroke's a header is not necessary if on a tight budget. You'll get a good improvement with one but, even with just the slip-on it's huge improvements over stock.

If you did jet maybe it needs to be tuned in a bit. If it's to large of a jet (rich) you'll get poor throttle response. Do you have the lid on or off? Make sure you have a good plug and clean filter. Lid off (jetted properly) can add some snap.

 

If you do the lexx slip on and have a k and n you should be around a 155 main jet. as for better throttle response I recommend doing the carb choke removal mod and rejetting the small jet (brain fart cant remember what that ones called) to a 42. Also the sparks 6 degree key is like 20 bucks and helps throttle response as well but you will need to run premium gas after that. Dropping a tooth in the front sprocket will improve snap and let you go slower to pick your line if you ride technical stuff...but if your in sand its nicer to have the extra momentum at the top of second for those long steep hillclimbs. Winchester bay is the place to test this theory btw and yes I have done all of the above mods and know from first hand experience how they affect your bike. Of course, you throw in a Cam or a big bore kit than you have to go up on your main jet accordingly.

/2cents

 

X2 on the sparks key.

 

i just put in my sparks key full big gun exhaust and removed choke threw in a 160 main and a 42 pilot..i cant wait to see how snappy it is cmpared to how it was