if I put in a cam, do I need to change the springs and rockers?
if I do a port and polish, will I need a bigger carb?
how about the clutch, will it hold up?

 

My 416 kit was just the piston and rings .Everything else we put together my self.This thing flys.I beat Raptors with full pipes and jet kits.I just beat a cannondale maped to a Speed with a pipe!!!!!

 

what did you do in the way of vavles???

 

Some aftermarket cams will need hardened rockers, and heavier springs, some won't. The xr400 cam and the HotCams don't need them. The manufacturer of the cam you are interested in will be able to tell you. The stock clutch should hold up just fine for a long time.

 

I put all big vavles with harden rockers and spings,also some port work. I used the stock carb put in a jet kit and removed the choke.I now have to put an up graded clutch basket inand another set of heavy clutches.

 

When I put my 416 kit in I went with 11:1, race porting, 5 angle valve job, White Bros race/track cam, oversized gasket kit, White Bros oversized head pipe and E-series exhaust, White Bros Rev box, removed the chock, jetted to 180, K&N with outwear, cut the top out of air box lid, removed snorkel and replaced with spray paint cover, removed air box drain plug, and ran #9 plug.

Worked awsome for 2 weeks and then i was breaking head bolts.

Put all new head bolts in then to take care of the extra power.

Worked awsome for almost a year then it seized up.

I found metal all through my motor from the clutch basket and inner hub. To much power for the stock clutch. It had also broken a small useless peice out of the side cover.

It had taken out my rod bearings. Couldn't get a rod kit anywhere's so I ordered a complete crank, the frist one I installed with all new gaskets was bent from shipping, the second crank was ok but my labour was now insane.

While it was apart this time I put in a new timing chain, checked the cam and rockers and decided to get a Fourstroke Tech oil cooler and drilled the case and valve cover and installed it. Runs alot cooler now and is much easier on the cam and rockers. I also put in a Billet clucth to keep it from flacking apart again also.

If your going to build your motor up do it right the first time cause otherwise it will cost you more then you'll ever get out of it.

Proud owner of one very powerful and fast ex, forever now.

I have pic's of every single new part in the motor and porting job, plus of the bike as is now and of a custom lowered job I did just for drag racing only about 24" high.

 

I have a JE 11to1 piston also.This will be my 5th set of clutchs my 4th moose set.Ive had this setup for sometime now and no problems.I run a 16-38 gearing also, I cannot beat the raptor or cannondale on top end. It takes them awhile at top end to catch me.

 

I haven't had to change my clutch plates yet, still the factory oem. Just the basket and hub needed changed. Running 15-36 gearing a DS 650 and I have exact same top speed

Running 16-36 gearing and good bye DS 650, Raptor, Banshee

When I dragged raced my bike last September in 300ft with 15-36 only a highly modded banshee beat me and at another event with 14-39 gearing a modified 400 2wd, 2 stroke Polaris gave me a really good run.

I've amazed Z400, Raptor and DS 650 owner's with my EX. Nothing like the other guy coming over to take a second look at your quad. I know some of it is due to driver skill and some of the guy's on bigger bikes but not of been as skilled as I but hey, I added a few more trophies to the 400ex trophy box. Now build us a bigger better quad Honda.

My next drag quad is a TLD Predator can't wait till it comes in later this week to run it again's my ex to see just how well they really do work for a Polaris. ;-)

 

Pleasure4qt: Please Please get back to us or just me about how the predator stacks up to your 416. I almost have your exact bike and my dad is considering building his like mine or trading his 400 in for a predator. Just lets us know..


Thanks

 

Don't worry, I will let you all know and try to post some good finish line pic's also instead of trying to figure out quad lenghts.