426 Kit Questions

[bkelley]

I'm thinking that with this year's tax return I am going to go for a 426 kit. I just wanted to start doing the research and lining up everything now. I'm looking at going for a 88mm 10:1 piston. Wiseco makes one but JE's 88mm only comes in 11:1 and 13:1 compressions, and I don't want to go that high. Are there any other companies worth checking out? I also want to go with a stage 2 cam, but don't know anything about cam brands. The only one I've even heard of is Hot Cams. As fo HD studs, I shouldn't have to worry about getting them with just a 10:1, right? What about a cam chain? Finally, I need to take out my Sparks key before I do all this but I lost my stock key. So, I was thinking about just going with a +3° key. Would that go well with the setup? I'll be running either straight 92 or a 92/100 mix. Oh, and will I need to worry about getting the valves adjusted or anything? I've never had and major engine work done to my EX before.

The main thing I want to know is where the best place to buy everything is. So far eBay seems to be the best option even though I have found a few other sites here and there. I've already emailed a few of the local shops to see how much they charge for cylinder machining. Even seeing how much they will charge to install everything for me.

This is what I have in mind:

Wiseco 10:1 88mm piston (http://www.mfgsupply.com/m/c/4606M08800.html)

Magnum Stage 2 Cam (http://cgi.ebay.com/ebaymotors/HONDA-TRX400EX-STAGE-2-CAM-CAMS-TRX-400EX-99-%2008_W0QQitemZ360227261577QQcmdZViewItemQQptZMoto rs_%3Cbr%20/%3EATV_Parts_Accessories?hash=item53df37cc89)

Top End Gasket Kit (http://www.mfgsupply.com/m/c/810829.html?id=PwpW8Fy4)

[lester985]

i got all my stuff from ebay its the best prices. as for cams hot cams u dont have to hard face your rocker arm or get hd valve springs it would be agood setup

[jcs003]

get four stroke tech to set you up with a 435 JE engine. when i had my 400ex it was very reliabl and the power output was amazing. go with hi-compression. if the engine is built right it is beneficial over running lower octane. plus more compression means more power.

[bkelley]

How much would that run me? I really won't have that much cash to spend. And I'd rather not have to run anything over 100 since I can get that at the pump from a Rebel station by my house. I don't want to have to go down to the shop and spend $70 on 5 gallons of fuel before every ride.

[lester985]

i have a 416 11:1 and stage 2 hot cam and 39mm fcr carb and the power is awsome. i work at a motorcycle repair shop and ive rode 416,426,440s the 416 setup right will give u just about the same power as all the others its all in matching the right parts the most high $ parts is not always the best do alot of research be for you do your build find a part check reveiws from people and see how they like it. i can give u agood one i wanted a new carb but not any stock carb like a 450r carb i wanted a eledbrock i got one for 200$ put it on and MAN junk just about i ride i have to reset it i gave it away and got a 39mm fcr it was like nite and day it worked so much better but i didnt research it could have saved 200$. i think i got a little carried away with this one :D

[bkelley]

Thanks for the info. I was basing my decision on how they say stage 1 is for low end and stage 2 is for mid to high end.

[lester985]

yes that is right

[bkelley]

Haha, I completely replied to the wrong thread. My last post was meant as a response to this:


Originally posted by monster400ex
for your wish list your better off with a stage one than a stage 2 hotcam with 10 to 1 compression
with a stage 2 you wanna go with a higher than stock compression at least a 12-1 i put it on my stock bore and comp and it wasnt much of a difference tiny more top end but now man is it ballsy
Originally posted by bkelley
Thanks for the info. I was basing my decision on how they say stage 1 is for low end and stage 2 is for mid to high end.

[jdog75]

Originally posted by lester985
i have a 416 11:1 and stage 2 hot cam and 39mm fcr carb and the power is awsome. i work at a motorcycle repair shop and ive rode 416,426,440s the 416 setup right will give u just about the same power as all the others its all in matching the right parts the most high $ parts is not always the best do alot of research be for you do your build find a part check reveiws from people and see how they like it. i can give u agood one i wanted a new carb but not any stock carb like a 450r carb i wanted a eledbrock i got one for 200$ put it on and MAN junk just about i ride i have to reset it i gave it away and got a 39mm fcr it was like nite and day it worked so much better but i didnt research it could have saved 200$. i think i got a little carried away with this one :D

true im more impressed with my magnum cam then hotcams and there 80$ cheaper

[bkelley]

Originally posted by jdog75
true im more impressed with my magnum cam then hotcams and there 80$ cheaper I saw a kit on eBay that came with a Magnum cam but I can't seem to find one by itself. I also found this, no idea what it is, though.

TRX400EX STAGE 2 CAM (http://cgi.ebay.com/ebaymotors/HONDA-TRX400EX-STAGE-2-CAM-CAMS-TRX-400EX-99-08_W0QQitemZ360227261577QQcmdZViewItemQQptZMotors_ ATV_Parts_Accessories?hash=item53df37cc89)

What about gaskets? I was reading in your thread that the namuras are pretty crappy. This look any good?

Honda Top End Gasket Set (http://www.mfgsupply.com/m/c/810829.html)

[jdog75]

Originally posted by bkelley
I saw a kit on eBay that came with a Magnum cam but I can't seem to find one by itself. I also found this, no idea what it is, though.

TRX400EX STAGE 2 CAM (http://cgi.ebay.com/ebaymotors/HONDA-TRX400EX-STAGE-2-CAM-CAMS-TRX-400EX-99-08_W0QQitemZ360227261577QQcmdZViewItemQQptZMotors_ ATV_Parts_Accessories?hash=item53df37cc89)

What about gaskets? I was reading in your thread that the namuras are pretty crappy. Anything from here look good?

Honda Top End Gasket Sets (http://www.mfgsupply.com/ATVWinderosaHonda.html/mv_session_id=GX4Q54mn)

thats funny i just looked at that cam before i read this post. but as for the gaskets i posted that about the namura gaskets they absolutly suck. i still have all of them but the headgasket wich lasted 2 hours. then i replaced it with the sparks one. but whatever you do dont but namura anything very poor quality. in one of my threads "cant catch a break" i posted a video of a namura piston that i found on youtube.

[bkelley]

Yeah, that's the thread I was talking about. Where can I get a Sparks 426 gasket kit? And what about that cam, think it's any good? I just asked the seller what brand it was.

[jdog75]

it looks like my magnum one but with different specs so it might be a stage 1 magnum. the only thing is you need to use a press to get the flange that holds the sprocket on. but if you could find one i would recomend a magnum stage 2 cam. very good mid to top increase.

[jdog75]

oh and about that kit thats who i bought mine from besides the gaskets no problems

[Honda#4]

Check out the site sponsor C&D Racing they do excellent work and are very fast and very helpful and there prices are reasonable. I Had my head sent to him for porting and he bored my cylinder so far im very happy with my power.

Buy a clymer manual and do the work yourself and you should save alot of labor costs plus its alot of fun.

[bkelley]

Originally posted by Honda#4
Check out the site sponsor C&D Racing they do excellent work and are very fast and very helpful and there prices are reasonable. I Had my head sent to him for porting and he bored my cylinder so far im very happy with my power.

Buy a clymer manual and do the work yourself and you should save alot of labor costs plus its alot of fun. I just sent C&D an email asking for prices. Also, I have the Clymers and I'm planning on doing everything myself.

[lester985]

how is th emag cam and is a drop in cam with no head mods

[bkelley]

Yeah, the seller said it's a Magnum.

[jdog75]

mine was the stage 2 and it was a drop in. imo it tops both stage 1 and 2 hotcams.

[bkelley]

Where did you buy it? I'd like to get a drop in.

[jdog75]

Originally posted by bkelley
Where did you buy it? I'd like to get a drop in.

in a kit from jci racing on ebay only thing you need is the sprocket flange pressed on

[bkelley]

Originally posted by jdog75
in a kit from jci racing on ebay only thing you need is the sprocket flange pressed on Yeah, I can only find them in kits, not separately. I'm gonna send jciracing a message and see if they won't just sell me one.

Edit: The guy from JCI Racing said he is going to list some today. He wasn't sure why they weren't listed already.

[bkelley]

C&D quoted me $400 for a piston, cam, gaskets and cylinder bore.

[Honda#4]

Not bad, I bought my gaskets and cam from Magic Racing. Heck when I brought my quad to the dealer they quoted me $500 alone in labor.

[bkelley]

Originally posted by Honda#4
Not bad, I bought my gaskets and cam from Magic Racing. Heck when I brought my quad to the dealer they quoted me $500 alone in labor. Yeah, I can get the cam, piston and gasket kit for like $240 myself and should be able to get the cylinder bored for like $60-$80 (I'm guessing, shouldn't be too much, right?) locally. So I don't know if $400 is good or not.

[bkelley]

Looks like I am going to have to hold off on this. Got my W2 and found out that I actually owe $24 in taxes this year thanks to Obama.

[scottdom]

hey bkelly, we just got done with my 426 build, holllyyy cow it rips. If your interested I can tell you what all I did. I was racing piped trx450r, piped Ltr450r, stock 700xx and this 426 beat the trx, lost to the ltr by half a length, and hung with the 700xx. good luck. can't wait to take it to Glamis.

[bkelley]

Yeah, man, I'd love to hear. I'm still gonna do it, just gonna take longer than I thought since I'm not getting anything back in taxes.

[scottdom]

you want the short version or long? We did a lot of homework, it will take me some time to tell all I learned and if you want I can send some dynos. I didn't dyno mine but the dyno I got was fairly identical to what we did. We think its putting out 40-42 horse. At first I wasn't sure I believed it but when I was running with 450r's who are putting out 40ish I started believing the dyno. I can post PM or to your email. Either way.

[bkelley]

I'm always down for a good story. Please, if you don't mind, PM me everything. And I believe th 40-42HP. Another member here posted a dyno sheet showing that a 426 was putting out more than a 450r with a pipe and stage 1 or 2 cam (I don't remember which).

[scottdom]

you got it. will try and send some pics as well.

[Miami_Vice454]

share the story with the rest of us. we wanna know too! :confused: :p :macho

[scottdom]

So my group here in PA goes to Glamis every year, its a big trip and big deal. One of the guys got us hooked on draggin up Olds, China etc. Obviously, the stock 400ex isn't competative and I didn't want to spend the 5K to buy a 450 plus more to hop it up. So we decided to be the "dark horse" and secretly build this quad. The other thought is that when we were done and I upgraded quads my wife could use the 426 when we go to Silver Lake, MI. 9 out of 10 reports said that the 416/426 builds were kicking the snot out the the 440 and you didn't suffer reliability and you were able to keep stock cylinder.

So here it goes. We started thinking we would stroke it but the more we talked to people that had them and the output of the crank and reliability of it, we opted not to do it. People were telling us of minimal hp gain and along with the stroker you need a custom piston. It all came at a steep price of $500. Is 5hp more worth that much? We didn't think so.

We had our local machine shop bore and hone it out for $75 and got the JE 11.1 piston. The thought was that since we weren't stroking it out and we were keeping a strong stock cylinder it could handle the higher compression. More compression = more power. Most shops and builder agreed. Stock compression is 10.1. The 11.1 piston was about $140 and I can run pump gas.

Some people did/didn't recommend the GT studs (not going to hurt) for the 416/426 builds but definately the 440. As long as the gasket isn't compromised you'd be good with a Cometic gasket kit.

Next was the cam. All research with dynos confirmed to go with a stage 2. Here's why. The stage 3 increases your top end but sacrifices a lot through bottom and mid range. At the top where you see the most gain with the 3 you might only utilitze a portion of it because of the rev limiter. Even with a CDI you weren't gaining that much and you were losing tons through out the rest. Cam was about 120.

There is a lot of hype about timing chains, so, I got the CRF 450 chain which was to be stronger and lighter that stock. NOT. The CRF chain was heavier and wider. When we put it on there was alot of side to side movement so since my 2000 chain was not worn we opted to put it back on.

I then went with a 05 TRX450r 42mm carb. Wow, did this open it up and the throttle response is awesome. Had to do some slight mods of the choke lever but was well worth the money. Found one on eBay for $150. Also did a open air box with an Outerwears and bored the inside of the pipe to carb to fill in any grooves that would slow down air flow. Got the 450r air kit from ESR and its the eliminator kit. That ran us $90ish.

My buddy is a self taught port and polish guy which he did for me gratis. THANKS TOM!! He ported and polished his YFZ 480 and YFZ 520 drag quad. (FYI, he ran and beat a 125hp alcahol Banshee at Silver Lake dunes, wouldn't have believed it, but I saw it with my own eyes.) Kept the stock valves and springs we just trued them up and checked for leaks.

Went with the Curtis Sparks pipe and header, had best dynos for the 400ex. Off eBay for $300. Did end up getting a Dynatek CDI to capture the last 500rpms of power. Its so minut that its hard to tell a difference.

Totally disassembled the quad, power coated the frame, swingarm, stock a-arms. Ahh yes, the shocks. More hype that doesn't work. 450r shocks are horrible of stock 400ex a-arms. Put the stock ones back on.

Went out to race friends in the field (stock gearing). Was really happy. Front end is light, might need extended swingarm. But man, when I pulled away from the piped 450r I was happier than a pig in mud. Couldn't wipe the grin off my face! The LTR450 was who ever got the best launch won. Again, big grin and a lot of hurt feelings.

[Miami_Vice454]

niceee man. im so glad to hear that becasue i have the same plans but only thing different is im doing 416 instead of 426 becasue i heard that it dissipates heat better. do you think i will still beat a piped 450r or at least be right next to him?

[scottdom]

I think you should do the 426. The money was the same and a well built 426cc should run better than the 416 and 440. I also wouldn't worry about the heat. I've talked to people about it and there wasn't any issues. Most complaints came from he 440's. In fact, in stock form, after a hard ride when I'd shut off my motor I'd hear a ticking from the motor. Like it was so hot as it was cooling you'd hear the motor contracting. Haven't heard that yet with the 426cc. Like I said earlier, I was racing a piped 05 TRX (don't think it had the HRC) and smoked him, was neck and neck with a cherry bomb, open pipe LTR, and neck and neck to a 700XX. Will be racing my buddies Predator 500 in Glamis in about 3 weeks. If you do this right you'll run with the slightly modified (piped) 450's but I don't see myself beating a well modified 450r like my friends TRX450 with an open air box, HRC, opened pipe. I will hang with him by two/three length but I won't beat him. But hey, to take a stocker at 28hp to close to stock 450r's that are 40hp is substantial in my mind. Good luck!

[Miami_Vice454]

thanks man, now you have me torn on whether to do the 416 or 426. im gonna talk to some more people and see what they think. man i only need 100 more bucks and my bday is in a couple weeks so watever i do at least i will do rollin in a few. thanks for sharing your story, it was a good one! :p :cool:

[bkelley]

I really don't see the point in going for the 416 if you're considering the 426. It's going to cost you the same and will produce greater gains. It won't sacrifice reliability, either. I'm going to be doing the 426 kit as soon as I can afford it. Think I will start things off with a 42mm carb and Eliminator open air system. That alone could fetch me 5-6HP.

[scottdom]

fact of the matter is....no matter which you go with, they are both going to run! I'm sure theres a 416 that runs just as strong as a 426 and visa versa. Why is that? Attention to detail. All the little things = hp and sometimes its the little things that get overlooked and its the little things that you do that will make you victorious in close races! Good luck to you friend!

[Miami_Vice454]

bkelley, have you talked to actual mechanics or just done your own research? of course i would do the 426 becasue you are going to see greater gains but i am just worried because an atv mechanic and a car mechanic both told me that i shouldnt do the last bore of the cylinder (426) because the cylinder walls become too thin. but on the other hand i have not heard of problems with the 426 so if you guys could give some more insight that would be great. and sorry bkelley i kinda jacked your thread. :rolleyes: