maybe a 416 now....anyone with a 416 chime in please....how long since you've rebuilt

[andy9743]

ok i went to my local quad shop and looked in to a cam and rasing the compression with keeping the stock bore. the guy kinda talked me into a 416 kit sorta. what i'm wondering is anyone that has a 416 kit how long has it been since you installed the kit? how's it still running? any iput on what results it had, different maintance etc. would be greatly appreciated, also please list what kind of kit you have. thanks

[Doibugu2]

your best bet will be to due a search. There is a ton of info out there on this site.

But most will agree the 416 kit is very realiable, has the fewest problems with head gaskets, and will give you a great benifit over stock.

But have you done any suspension work yet? That will give you the most bang for the buck.

[UglyMotha™]

mines handled a season of pretty hard beating so far i just tore it down and everything is looking pretty sexy so i'm not replacing anything even my old style hot cam is still in tip top condition no loosey flange either

3 years on my 416 kit. Everything in there is the same since the day it was installed except the head gasket and it was replaced when I pulled the head off to install a heavy duty timing chain.:cool:

Very reliable as long as you don't go to high on the compression.

[Silverfox@C&DRacing]

mine is due for a rebuild installed 416 in April of 2000 :eek2: they will last quiet awhile make sure you keep you filter clean and change the oil often ;)

[andy9743]

what kits do you guys have? my builder quoted me a price of 640 w/ everything and labor for a wiseco kit. i know you guys like je or ross, but why? i'm gonna give him a call and see if he can do a ross or je instead, what compression do you guys think???


thanks again:cool:

[andy9743]

he said it's an 11 to 1 that he quoted me for, that sounds a bit high to me for my needs, should i go lower? he also said he'll put any piston in it that i want, what should i request? i'm gonna go get the deposit put down as soon as i know what i should get, suggestions please!!:D

[nicky slee]

I just had CT Racing build my top end. It's a 416 also. They did port and polish, lap valves, 3 angle valve job, hot cam stage 2,11:1 piston(WISECO) and bored and chamfer ports for $725. All i can say is be nice on break in. How you break it in will depend on the life of your bike period. 11:1 is not to high of compression i don't think cause you can still run super unleaded or 4 to 1.

[UglyMotha™]

don't baby the break in, but don't beat the crap out of it, break it in like your goin to ride it

[DantheEXman]

Originally posted by UglyMotha™
don't baby the break in, but don't beat the crap out of it, break it in like your goin to ride it

Correct.

Iv had my 416 for about 2 months. Its a great difference over stock. It pulls much harder through all the gears and revs extremely fast. Really gets the power to the ground.

[lilpoppy]

I have had myne for about a year now and the only problem I have had was a head gasket blowing. I'm running a Ross piston because is it the lightest and supposedly revs faster because of the weight. I'm also running the Hotcam stage2 cam which I have never had a problem with. As far as power gains go I have quite a few mods other than just the piston and cam but with my mods I can consistently beat the 450r and the yfz's out in the sand drags. I deffinatly recomend it.

With 11:1 you might have to run race gas. I noramlly run with race gas but I have run it without and I have never heard it pinging.

[andy9743]

thanks for the reply's guys, i'm still not sure on compression though, i've been getting mixed replys...11 to 1 is ok with pump gas, 11 to 1 needs race gas, what would be the next step down from an 11 to 1? would it be better to step down one "compression step" just for the sake of running pump gas? i ride trails mostly, never racing, and sometimes i find myself at some pretty old school gas stations, some with no higher octane then 92....what do you think?

[400EXcrazy]

i got a 416 kit with hot cam stage 2 and i got 10 and 8 compression and i run 93

[cals400ex]

you can get a 10.8 or 10.5:1. also, you can tinker with gaskets to raise or lower your compression.

[nicky slee]

Dude with a 11:1 comp. you can run 92,93,100 its all fine. I promise:)

[UglyMotha™]

no it's not :huh you don't know that for sure

a true 11:1 is a fine line in the middle it has the capibility of goin either way there are one to many circumstances that will decide whether or not he'll need to run atleast a race mix so not you or anybody else can just up and say "no you won't have to run race gas"

An 11:1 compression piston can run on 93. But it's not going to run near as good as it would with a higher octane. I mix 93 and 110 at a 50/50 ratio and she runs like a champ. I have the 10.8:1 piston so it runs fine on 93 also, but it pulls harder with the mix in there..

I'd go with a 10.8:1 and that way you know for a fact that it will run on 93.

[nicky slee]

Originally posted by UglyMotha™
no it's not :huh you don't know that for sure

a true 11:1 is a fine line in the middle it has the capibility of goin either way there are one to many circumstances that will decide whether or not he'll need to run atleast a race mix so not you or anybody else can just up and say "no you won't have to run race gas" Yes i can say that for sure! Not sayin it run as crisp as it would with 50/50. Since your such a smart guy:rolleyes: tell me why i can't tell him that? CT racing told me that so they build engines but they have no right to tell people that!

[lilpoppy]

If you are worried about it then deffinatly go with the 10:8 compression. You more than likley could run it on pump gas but why risk it. If you decide you want to up it later on down the road all you have to do is swap it with a different size head gasket.

[Silverfox@C&DRacing]

Originally posted by nicky slee
Yes i can say that for sure! Not sayin it run as crisp as it would with 50/50. Since your such a smart guy:rolleyes: tell me why i can't tell him that? CT racing told me that so they build engines but they have no right to tell people that!

Depends on altitude, temperature and Humidity
pump gas isn't all the sam the highest we get here is 91 I have been told by others in different states they get 93-97 at the pump.

[lilpoppy]

Well I just tore my engine apart and I found that my cylinder studs striped out so I would recomend getting the heavy stud bolts if you are gonna get the 416.

[jp8400ex]

Have you considered a 406? Save yourself an overbore and cant imagine much of a power diff. from an equally built 416. Plus if you are worried about heat, a 406 won't have as thin a sleave as a 416 so it should run a bit cooler. I have a 406 and love it. Just my .02

[amosclifford]

well i talked to a few places about416 and 440:cool: and they all gave me pretty much the same answer:o use honda silicone for the base gasket and a xr 400 head gasket to acheive true compression for the piston. 99% of the pistons out there were designed for the xr400 so the coompression ratio is not exactly accurate for the 400ex. the best bang for your buck would be the 406 or 416 with the xr gasket and 11:1 piston. i rode alot of different places with mine and no pinging at all on it no matter how hot it has been:devil: all on premium

[DantheEXman]

I used all stock gaskets when I built my 416, So If I swapped the head gasket for an XR, I would gain more compression/power???

[amosclifford]

well even the tch articles on this site under the ask mickey dunlap part 2 touch base on tis but answer is most likely yes

[andy9743]

what a bunch of great resomnses, thanks guys, i dropped it off saturday for the 416 build, i'm gonna go with an 11 to 1, but with 400ex gaskets. i know it won't have quite the power, but i my compression will be lower and i'll have less to worry about. my builder is also going to "trail port" my head a bit and i'm looking at picking up a fcr, maybe. thanks again