Alright everyone, who here is the most knowledgable on the Honda's?

 

lol what do u want to know young weekend warrior

 

What I was wondering was if you ground the welds on the stock headpipe and removed the choke completely on the carb would it be worth the effort? Also, considering a rev box.

03 honda 400ex-modified

 

You must be talking about the inside of the head pipe. Taking out the choke and "porting the pipe" would be worth a little... but don't forget to jet to compensate... yes, even the pilot. The ex is cold blooded enough, your going to need alot of pilot to even get it started... I don't think the rev box will do you any good unless you have a quality pipe and get it jetted in.

 

id go with what he said lol

 

the porting of the headpipe and removing the choke is free. why pass it up?? just remember to make sure your bike will start without the choke before you go and remove it. the rev box will only be beneficial if you have an aftermarket cam that will enable your bike to rev past the stock limiter.

 

Bike mods are as follows: 440 bore 11:5 to 1 ross racing piston and a stage 1 webcam, K&N without airbox lid,and a White bros. R4 muffler. Also would a Magnum or other Rev Box be okay with a stock rod in the motor?
Thanks for everyones help, I really appreciate it...

 

I don't know how much of an increase you will see but it will have some affect. I took my header pipe off and ported it you would not believe how fat of a weld that they live in there. I would bet that I increased exhaust flow by 25%. I have not taken my choke out but if you do you better move that pilot jet up alot.