Building a 416ex

[01400ex]

Hey guys Im new to the whole big bore kits and modden a fourstroke.(had a blaster)
Anyways what all do I need to build a good running 416ex.
I know some of the things like a piston and cam and other stuff.
What all do you reccommend? Should I buy a kit that includes everything off of smarks? or buy the stuff individually?

People that have a 416 was it worth it can you now smoke piped 400ex's?

Later Ryan H.

[ROGERS]

Check RAZORBACK's recent post about the addition of a 39mm FCR carb to the 416 kit. This setup is very popular and very potent. I have a stock engine and it is VERY hard to keep ahead of the 416 kitted quads.

Basic setup seems to be 11:1 non-Wiseco piston, Hotcam stage 2, ported head and 39mm FCR. Exhaust, however is where you will find the most discrepency of opinions. I think the Alien exhaust is trick and sounds great.

Happy Building,
-Josh

[JD400exrider]

You will find most of the guys here seem to be running the hot cams stage 2 cam.
A JE or Ross Piston. 10.8-1 or 11.01 compression.
A steel head gasket. TRX or XR gasket. The xr gasket is a little thinner and will increase the compression a little.
With the hot cam, HRC cam or the XR cam you can run the stock valve springs and rockers.
Porting and polish is an option but a good idea. At least a clean up port job.
Three angle valve job is an option depending how much time is on your motor.
Install new valve seals. Cheap and good insurance.
There are other more aggressive cams but most should have hardened rockers and heavy duty valve springs. The aggressive sparks cam is a drop in but i have heard heavy duty valve springs is recomdned.

I would get a engine builders exhaust. Sparks, LRD ect. I live in CA and they won't pass the noise cops. They are starting to test everywhere i ride.

As far as the fcr 39 carb. That is lickely in the future for my 416.