I want to get a FMF Power Core IV 2 Slip-on for my 400ex. Should I get the spark arester version? Will I need to rejet? Do I need to get a Jet kit? How much horsepower will it give with just a slip on? Any tips would be appreciated. Thanks

00 trx400ex - ac mudscreen front bumper, nacs headlight covers
86 trx200sx - powersport bandit 20 in rear tires

http://www.geocities.com/cory_14/

 

As far as I know they only come with a spark arrestor already installed.. I use it and it is sweet...

 

I am running the Power Core IV 2 also. You will need to jet your carb. I ran mine for 2 days without the jets. I DID notice a performance gain even without the jets even though it was running pretty lean.

I am using a Uni Filter with stock airbox and a 160 main with this pipe seems to run nice. Not rich or lean.

Eric

 

I was told by the people at Rocky Mountain ATV that I would probably not need to rejet with this pipe and my K&N. I have logged about 12 hours of hard riding with this pipe and I have never bogged down or hit dead spots. I don't plan on rejetting until I get the Power Bomb. I couldn't give you an exact horsepower gain, but it was VERY noticable. Blows the plastic off my buddies 400's with the MegaMax and the Big Gun. Unbelievable low end power and torque.

 

As for power... I lined up against my buddies stock 400EX and he was looking at my exhaust tip with a telescope. 1st and 2nd gear, I was just fighting to hook up and keep the front end down, I had a small lead...once I got into 3rd and 4th it was over... not even close.

Eric

 

Skunky, how much you paid for your RPM a-arms and swinarm. And how can I find RPM, do they have a website. Thanks for your help

 

My buddy has one on his and picked up about 2-3mph! And it is loud

 

if you do not make any airbox mods you do not need to rejet but i rejeted and but my airbox lid back on and between 3/4 and full (main jet time) i would bog.. That is because there was not enough airflow with my K&N and exaust flow... Wet plug.. Took off airbox lid and was flying... As for the RPM swing-arm and a-arms I paid 400 for the a-arms and 300 for the swing arm(actually I upgraded his computer). I know the guy that makes them for RPM So he hooked me up... I might be able to hook you up... My custom Stainless Steel braided brake lines are awesome too... www.rpmracing.com but there website is being made..

 

JDSUAREZA---- I replied at bottom

 

How loud is the PowerCore IV-2 compared to a White Bro's E-series or Supertrapp with all the disks in?