After the pipe, k&n filter, and jet kit on a 400ex. What modification would you add next and in what order would you add them. Engine mods only!

 

I also would like to know what engine mods to do
so far I only have K&N air filter with 6 vent holes,FMF powercore IV2,155 jet,DGnurfs,Garydon Proline front bumber,TimmyBoy +2+1a-arms,front TCS shocks,ceet grapihic kit,renthal bars.SOON new rims and tires once I know what to get.BUT no engine mods.
SO it about time to DO some, any info on what to do would be great.

 

port job,bored,high compresion piston,cam,rev box.
it makes a world of difference, PRO FAB ATV in ohio (740)654-0734 they now what they are doing me and a buddy had them done there and they really haul now. will beat a stock ds650 in a drag

99 426ex,11:1,port job,web cam,rev box,k/n,dyno jet kit,6 air box vents,ids-2 super trapp pipe,
14 tooth front sproket = power

 

next you might go with a high rev cam and black box mod. then maybe a high compression piston. maybe port and polish,bigger carb or have your stock carb bored,and if that doesn't do it for ya then you could get a 440 kit. later

 

Do you know how many mm of increased bore it is to reach 426cc? Can you run 11:1 on pump gas? Do you have a larger capacity oil tank and if not does it heat up very bad? Also, what made you use pro fab atv to build your motor as opposed to TC, Sparks, Four Stroke Tech, etc. Was Pro Fab able to give you horsepower figures for your combo and if so what were they? And now the big question, how much$$$$$$$. Thanks!!

 

well its bored 120 or 130 over, i run 92 or 93 octane which ever one i find and it runs great.
i have the stock oil tank on it, and doesn't seem to run any higher. how i chose them was i just called a few # out of dirt wheels seen there ad in the mag for qite some time now, and he really sounded like he new what he was talking about. as for the horse power, good ? i never asked him.

1.bore $45.00
2.piston kit $150.00
3.cam $169.00
4.port job $375.00 (wow)
5.rev box $99.00
6.motor work $150.00 (or just take/send him the top end and save $150.00)
and let me tell you it is worth every penny!!!