Getting the most out of a 416? What do you think?

[rr4406pak]

Hello all,

Just installed a 416 JE 11:1 piston and Stage I Hotcam on the 400EX. I have a 155 main jet installed with the stock exhaust (spark arrestor & silencer removed). Also running a 14 tooth front sprocket, stock rear sprocket & 18X10.5-8 Kenda Klaws on Hipers on the rear. :D

It seems faster than stock but not world's better. When I get into the mid to upper RPM's it starts to really charge like it never did before. I really did notice that. With the 14 tooth front gear and the small 18" rear tire I go through the gears quick! Lots of torque for aggressive trail riding which is what I love.

I thought it was fast till my buddy brought over his brand new 2004 Predator 500 (brand new overstock from last year) he paid $4400 for it. He let me ride it and it was noticably faster than my 416EX. Way faster. :ermm: I guess it's hard to beat the liquid cooled motors that's for sure. I smoked him on the trails though cause he was scared of the power and does not know how to ride it yet. But once he gets the hang of it I think I'm in trouble! :eek:

Question is: With my stock exhaust pipe opened up, am I getting all the power out of this 416 kit? Would an aftermarket exhaust really give me that much more? Any tips are appreciated. Thanks!

[400exredrider]

should have gone stage 2 cam,, port and polish and a FCR39 or 40mm carb,,, then you can take predators also full sparks x6

[400exredrider]

forgot to mention K&N

[Flynbryan19]

The gutted out stocker pipe sucks. Your losing alot of horsepower right there. As 400exrider noted, you can get alot more out of that motor by doing the mods he listed. But make no mistake, that Pred is a pretty fast machine.

[wilkin250r]

Did you install the 416 yourself? Do you know if the deck height and squish is set up properly? The 400EX is a little goofy, it really requires special attention.

The Hotcam, or ANY aftermarket cam for that matter, is designed to work with a free-flowing exhaust. So right there, you're not getting all the performance that you can out of the restrictive stock exhaust.

Where is the Predator faster? Acceleration or top-end? With a 416 (if it is set up properly), you should have enough power to pull the stock 15t front sprocket.

[400exredrider]

predator should start to pull at top end,,, low to mid 416 is strong.,, even a slip on with a ground oth stocker is a good setup,, stock ground out header provides more low end grunt,, but yeah make sure its all correctly meshed and everything is set perfect

[T.Hopp]

If you look at the stock exhaust w/ spark arrester, quiet core removed; you will see a tube protruding through a plate at the mid point of the exhaust can. This plate is stainless steel but can be drilled with a sharp holesaw. I used a 1-1/8" holesaw to drill a hole in the center of the plate. Once drilled, you can see directly through the exhaust can, front to back. Not as good as an aftermarket but it should let it flow more freely.

[cals400ex]

the predators are fast, even stock ones. i don't think you will be able to build your ex to compete with it up top. well, i guess you could but not reasonably. your gearing is really really low. if you go with taller gearing, you should have better luck dragging. i would probably run like 16/38 gearing with that setup unless you want all bottom end power.


you said you have no silencer?? did you remove the spark arrestor only or the whole silencer :huh

[rr4406pak]

Sorry about that. I removed the spark arrestor not the silencer.

Thanks for the advice guys. I had the 416 kit put in by a performance shop locally and I do currently have a K&N filter on it. I think I'm going to put the 15T sprocket back on and look for a good aftermarket exhaust. Do you think I'm doing any damage to the motor by using the stock exhaust? Or is it just simply restricted?

To answer the other question, the Predator was faster on the top end. Way faster...

[400exredrider]

yeah but you can build a 416 to keep with it for 300 yards or more

[BIGRED400]

Your 14T is killing you,maybe fast out of the hole after that you're done.............been there done that,I have a built 416 w/factory sprockets that will spank a piped Shee !:D

[cals400ex]

higher gearing will make you quicker. a 16 will probably make you quicker than the 15 even if i had to guess. the stock pipe wont hurt the motor. your just not getting all the power you could be. i would guess the predator will still pull on you pretty good top end even with a 16 tooth front on (with 18's on the rear) and a good full pipe. the bike should run much better though.

[Dave400ex]

Put it back to stock gearing and get a full HMF exhaust and you should see quite a difference. If you still need more, you might have to look in to a more aggresive cam, port work, and maybe a carb.

[Rico]

18 inch rear tires and 14 tooth sprocket is the worst combo you could ever run. Go back to stock gearing and running that 11.1 piston on 93 or less octane is cheating that piston compression of what it can really handle.

A slip on pipe and slightly opened airbox lid would REALLY bring that thing to life.

[cds]

Remember this, the Predator is only faster than your Honda when it runs :p

[speedy400]

My 416 has been running strong for... a good 2 years and a few months now. I love it.
-Uni filter
-Open aluminum airbox
-FCR39mm
-My porting and polish job
-10.8 to 1 comp je piston
-stg 2 hotcam
-powerbomb header
-HMF slipon
good setup
-darren

my 416 was set up practically identical to yours rr4406pak it was quite impressive through 1st 2nd and 3rd but after that it died out. The full exhausts needs to be added for the extra power up top and maybe you should use some bigger tires for speed up top too

that 84cc displacement realy helps the pred

i sold mine for a 450r if i were u i would to

my stock r smokes a pred off the line but it catches up with me on top of 5th gear