416ex Review

[Atreyu]

Well I just finished breaking in my new 416 motor. It's almost like riding a completely new quad. I went with JE piston 11:1, hot cam stage II, relapsed valves and new seals, and headport. It added a lot more mid-range and topend. It pulls extremely hard in second and third. Definately worth the money..

All work was done by C&GATV..good job guys;)

[hondaexryda]

cool have fun, i was thinking of getting 416/426 kit , but deciding to go with YFZ or TRX

[mustang93]

what fuel do you run?

[Atreyu]

I'm going to run 94 I think.

[F-16Guy]

My girlfriend, my brother, and I went to Ogilby (Glamis) a while back, and while we were stopped at the bottom of some dunes taking a rest I jumped on my girlfriend's stock 400ex. Man, what a difference! I forgot what it was like to ride a stock bike. I was barely making it up one of the dunes that I was just playing on with my bike. It was definitely money well spent; I could never go back.:macho

[Billdog350]

I'm really thinking of doing this to my 2000 400ex. What octane are you guys running? I don't want to have to mess with race fuel or Cam2.

Originally posted by Billdog350
I'm really thinking of doing this to my 2000 400ex. What octane are you guys running? I don't want to have to mess with race fuel or Cam2.

Then don't go above a 11:1 compression piston..:cool:

416 kit and cam upgrade does wonders to a 400ex. And for the cost it's less than buying a full race exhaust system..:eek: You'll also get more power out of a 416 kit..

[Billdog350]

So 11:1 is the upper limit...I have heard that JE and Weisco have the 11:1 kits...but the "true" compression on the JE is higher than the Weisco depending on how you measure it. Any truth to that?

Also, I have a pretty well stocked garage. I have a 12 ton press, plenty of power tools, 250 Amp arc welder, etc. I know I'll have to send the jug to be bored if I go oversize with the piston, but besides that do you think it's an easy enough job to do myself? I have rebuilt a Chevy 350 motor in the past, as well as done a few clutch installs by myself so I have average or above average backyard mechanic skillz....I don't want to get into something over my head and have to send a basket case to my dealer, but at the same time his quote of $1100 for the piston, cam, and pipe installed seems a little steep.

Originally posted by Billdog350
So 11:1 is the upper limit...I have heard that JE and Weisco have the 11:1 kits...but the "true" compression on the JE is higher than the Weisco depending on how you measure it. Any truth to that?

Also, I have a pretty well stocked garage. I have a 12 ton press, plenty of power tools, 250 Amp arc welder, etc. I know I'll have to send the jug to be bored if I go oversize with the piston, but besides that do you think it's an easy enough job to do myself? I have rebuilt a Chevy 350 motor in the past, as well as done a few clutch installs by myself so I have average or above average backyard mechanic skillz....I don't want to get into something over my head and have to send a basket case to my dealer, but at the same time his quote of $1100 for the piston, cam, and pipe installed seems a little steep.

If you have a service manual then you'll be more than fine doing the work yourself.:cool:

You should be able to get a piston, rings, gaskets, and drop in cam of your choice for around $300.

I have a 10.8:1 JE piston in mine and it runs just fine on pump gas and it also added a nice kick to the motor.. It's also not to high in compression that you'll blow head gaskets or pull head studs.

[Billdog350]

I have the electronic version of the service manual...so I should be set. Is there anything else I need to know before diving into this? I know pipe and carb may need to be upgraded eventually, and somethign about hardened rockers? Anything else?

[Hondaluva]

...do you think it's an easy enough job to do myself?

If you have the skills to turn on that arc welder and can read and follow directions, you will have no trouble tearing down and rebuilding the top end. It is very easy!!!

A lot of aftermarket cams use an old stock cam and hard weld the lobes and then regrind to get the profile they want. If the cam you choose is a regrind, you will need hardened rockers. I know for sure that HotCam makes new cams (no core charge:D ) and they work well with stock rockers as long as the rockers don't have major wear.

Dive into that engine, you'll enjoy it!!!

[iride440ex]

I went from the 440 kit to the 416 and personally I think the 416 pulls harder than the 440 kit and I don't worry about pulling studs no more. I went with the Ross piston it's a little lighter for quicker revs.

Tony

how did you go down from a 440 to a 416? :huh i didnt think that was possible

[Billdog350]

I'm pretty sure I know the answer but I figured I'd ask you guys anyway.....is that cylinder nikasil coated or not? I don't think so, but I figure I'd get a definite answer.

[F-16Guy]

Originally posted by Billdog350
....is that cylinder nikasil coated or not?
Nope.

[Billdog350]

This should be my last post before I order up the parts for this. Ok, so I have a stock pipe with billet end cap, stock carb -w 155 main and 42 pilot, 14t front and 39t rear sprocket, uni filter, Sparks timing advance key.

I plan on a Stage 1 hotcam, JE 10.8 or Weisco 11:1 piston (416 kit), new gaskets, rejet for mods (160+ main).

I understand I'll have to remove the advance key because of the high compression, that's ok. Also, I'm not racing, just looking for a bit more "bang for my buck" than just slapping a pipe on there and rejetting again. So, my question is: what is the minimum I should put into the mods to keep up with the high comp piston? I don't feel like a new carb, pipe, rev box, etc...but if I need them to make the engine run correctly I'll obviously have to consider that.

[Dave400ex]

I would look at getting the Stage 2 cam since you are getting a high compression piston. Also stick with the JE piston. You will be fine with the stock carb and rev box, just look at getting a full pipe. Call C&D Racing, they have everything you need.

[Billdog350]

Thanks for clearing things up...I didn't think I'd need a different REV box or Carb for just woods/trail riding.....but I guess the pipe makes sense....I'll check out some on eBay I guess, before I order the kit.

[Dave400ex]

I would check out a HMF pipe. Priced good, and high quality.

[F-16Guy]

You could also do a couple of free mods. There is some debate on whether or not they add noticeable power, but I think they definitely couldn't hurt (I've done both). One; remove the choke mechanism. You can find this in the "tech aritcals" section. After I had my 416 built and installed a 42 pilot, I've never needed to choke my bike to get it started. In fact, my 416 is probably the easiest starting four stroke I've ever seen. In theory, removing the choke mechanism increases airflow due to less restriction. Two; when you have your stock headpipe off you can grind the beads of weld that secure the machined mounting flanges to the headpipe. I used a high speed grinder, but you can also use a Dremel. The beads are on the inside of the machined flanges, just grind them to match the inner diameter of the headpipe. Again, more flow, less restriction. Both mods should only take an hour or two.

[Billdog350]

I did the 42 pilot and it seemed to be much better.....but I can't say that I don't need the choke when its 20-30 degrees outside....I'll have to see on that.

As far as the header pipe, I plan on using my die grinder and cleaning any welds or things out of it...and also possibly mildly porting the intake and exhaust of the head while I have it off. Has anyone done any porting/polishing on their 400ex? Any suggestions? I know you can't take too much material off...and you need to make sure it's smooth when you're done.....but besides that?

[spliffy]

Originally posted by Billdog350


I understand I'll have to remove the advance key because of the high compression, that's ok. Also, I'm not racing, just looking for a bit more "bang for my buck" than just slapping a pipe on there and rejetting again.

Why do you have remove the advance key? we just did my buddies 416 with a 11:1 & stage 2 cam & I never heard of doing this.... help i guess?? :confused: :confused:

[iride440ex]

Originally posted by Jumbo747
how did you go down from a 440 to a 416? :huh i didnt think that was possible

I bought a new cylinder the studs got pulled out of the 440 cylinder. :rolleyes:
Tony:

[Billdog350]

I have heard from a few sources that if I want to run PUMP GAS that I need to remove the key. Are you guys running race fuel, cam2, or a blend? If so that would explain it. I'm looking to run 93-94 octane with my 10.8-11:1 kit.......so to keep it from pinging and overheating, I'll need to remove the key. Does anyone have any comments to the contrary?

[Silverfox@C&DRacing]

I have the JE 10.8:1, thinner gaskets, degree key, hot cam stg2, fcr carb and I normally mix a little bit of b32 race fuel I had the stock carb on for a ride and did not mix any fuel and it was pinging a bit I did not realize what it was then I had Colby ride my bike and he said I needed better fuel so I added some b32 and the ping was gone.

[Billdog350]

I think if you yanked your key you wouldn't have to run the race fuel. At least that's what I'm hearing from other people.

[Atreyu]

Originally posted by Billdog350
I think if you yanked your key you wouldn't have to run the race fuel. At least that's what I'm hearing from other people.


I"ve heard this too.


I just got my 8x8beadlocks and 18''razrMX's on there too. This thing rips now, it's kinda hard to get used to. It pulls 10x better than stock. Amazing what $600 will do.

[EXDUNER127]

Just mix your gas, half race-half 91, and you will be fine, sparks says you can keep the key in unless you do the 440.

And if you do cam and piston you are gonna want a new head pipe, more airflow the better, especially when you, if, port the head. I had a stock grinded weld header and WB R4, and then my engine builder recommended me trying a the biggun full exhaust and i beat my friend with the same mods except for the full ex. and i beat him by 3-3 bike length up olds, and i usually get him once i hit third and 4th gear. just my .02

[Billdog350]

EXDUNER127, if you read my post, I don't want to have to run half race fuel. I'd prefer to be pure pump gas if possible. Eeking out .5 hp but needing race fuel is not worth it to me. I'll yank the key and see how it runs.

[BIGRED400]

Originally posted by Silverfox@C&DRacing
I have the JE 10.8:1, thinner gaskets, degree key, hot cam stg2, fcr carb and I normally mix a little bit of b32 race fuel I had the stock carb on for a ride and did not mix any fuel and it was pinging a bit I did not realize what it was then I had Colby ride my bike and he said I needed better fuel so I added some b32 and the ping was gone.

What thickness gasket's to get 11:1 ???? I PMed Colby but he never got back with me:rolleyes:

[F-16Guy]

Get the XR400 gaskets. The head gasket is slightly thinner. If you want to live on the edge, you can run no base gasket (just a thin bead of high temp gasket maker) and use one layer of the head gasket. You have to remove the rivets from the 3-layer steel head gasket and paint one of the layers (either top or bottom, I think) with high temp BBQ paint. According to Mickey Dunlap, this gives a better squish area around the edge of the piston and also improves flame travel characteristics. Basically, the combustion will be cooler and more efficient, allowing you to run the same octane fuel despite the higher compression ratio. Mickey and a couple others have run engines like this and claim to have no reliabiliy problems. I might give it a try next rebuild :D

[markk]

I run my 416 on Amacco 93, But when im running my quad in a race I like to run race fuel. 50/50mix or straight! It seems to rap up quicker, like the fuel was packing just the punch i was needing.
And when the summer months come around and its starting to get warm its alot nicer on your motor to run a higher octane fuel! to keep form spark knocking!

[Xowner]

were are you guys getting the je pistons id like to go just under 11:1
do you need porting with a new cam also which is better for woods stage one or stange two?
Thanks

[cals400ex]

there is a nice deal going on at C&D racing with ross pistons. they are selling standard bore, 406, 416, 426, etc pistons for a good price. if you look at the top of page 1 in this powertrain forum you can see the post. it is a sticky so it will be at the top of the page. you can get the 416 in 10.8:1 compression which is right under the 11:1 your looking for.

[quadkrazy400ex]

i ordered the kit from c&d too. 416 10.8:1 ross piston good deal

[Xowner]

ok guys i look at their site it says for 130 Piston Kit Includes (Piston, Rings, C-Clips, Wrist Pin, And Gaskets

is that true some sites want 60 for the gasket kit?

also i see je weisco but no ross?!?

[cals400ex]

it won't be on the site probably, you will need to call them.

[quadkrazy400ex]

call them up and order the 416 10.8:1 compression piston kit for 105 dollars and get the gasket kit for 40..you can choose from either a thin base gasket or the thicker one