Help me build my 416!

[awsomeaussies]

I'm going to be building a 416, well actually a 415;) So far I have the Powroll 415cc bore kit. 87mm forged piston, 10.8:1 compression
Includes: Piston, pin, rings, circlips, headgasket, basegasket
I'm also going to get a Stage 2 Hotcam and a 450r carb. And I already have the HD studs... I know there not necessary with a 415, but I figured better be safe than sorry.

What I need some advice on... is what else should I do? Such as should I get a 3 angle valve job? Is there anything I'm missing? I'm thinking I'm going to have GT thunder install everything.

[vett_09]

You could have a port and polish done, and get an aftermarket CDI. What exhaust are you running?

[awsomeaussies]

Originally posted by vett_09
You could have a port and polish done, and get an aftermarket CDI. What exhaust are you running?

I'm running a Sparks X6 exhaust. I've heard people running different rev boxes and CDI's... but I'm not exactly sure what a CDI is and whats the advantages of both?

[awsomeaussies]

This is a very blonde moment for me... but where does the hotcam go??? I'm trying to figure out what all I need GT thunder to do engine wise. So far installing the bore kit, boring, installing the HD studs and a valve job. Would I send them the hotcam? Or is there anything else I should have them do?

Originally posted by awsomeaussies
I'm running a Sparks X6 exhaust. I've heard people running different rev boxes and CDI's... but I'm not exactly sure what a CDI is and whats the advantages of both?

A cdi box wil let it rev about a 1000 or more rpm higher. Big guns can add up to 2 hp. rev box is the cdi just some people call it a rev box but the real name is cdi..

[Chin_Chilla]

When installing high compression pistons and aftermarket cams, you should really take a look at the cam chain, inspect the valve seals and springs. If those are worn, get a nice set of Kibblewhite Black Diamonds with titanium springs and new seals. A port and polish wouldnt hurt while the top end is apart. 3 angle valve job like you said, if money isnt really an issue. Also take a look at your clutch if you are running stock. I upgraded from stock to a Barnett Dirt Digger kit, there are better options but for me money was an issue lol. That about sums up all you need.

[oldskoolex400]

i wouldnt buy a CDI its a waste IMO.............. had too many problems with a big gun cdi anyway maybe others or better, i sure know my sparks held up good, was it worth it though, NO lol

[awsomeaussies]

Originally posted by turtlebus
A cdi box wil let it rev about a 1000 or more rpm higher. Big guns can add up to 2 hp. rev box is the cdi just some people call it a rev box but the real name is cdi..

Thanks! I just did some research on some brands... and I think I'm gonna go with the GT Thunder one. Plus he can just add it on my bill:p

[awsomeaussies]

Originally posted by oldskoolex400
i wouldnt buy a CDI its a waste IMO.............. had too many problems with a big gun cdi anyway maybe others or better, i sure know my sparks held up good, was it worth it though, NO lol

:ermm: I wish I could try something before I buy it. lol It's so hard to figure out what to do:mad: Maybe I'll just ask Laz to see if its worth getting it.

[Chin_Chilla]

Originally posted by oldskoolex400
i wouldnt buy a CDI its a waste IMO.............. had too many problems with a big gun cdi anyway maybe others or better, i sure know my sparks held up good, was it worth it though, NO lol I've had my Big Gun CDI for about 6 months already with no problems...why do you say its not worth it? To me it was very worth it. JW...

[awsomeaussies]

Originally posted by Chin_Chilla
When installing high compression pistons and aftermarket cams, you should really take a look at the cam chain, inspect the valve seals and springs. If those are worn, get a nice set of Kibblewhite Black Diamonds with titanium springs and new seals. A port and polish wouldnt hurt while the top end is apart. 3 angle valve job like you said, if money isnt really an issue. Also take a look at your clutch if you are running stock. I upgraded from stock to a Barnett Dirt Digger kit, there are better options but for me money was an issue lol. That about sums up all you need.

I'm running a EBC HD clutch so I think that will work. Money is an issue... but I figured might as well do it right the first time and hopefully I wont be left wanting more:p I'll look into the Port and Polish, but I heard that it doesn't help as much as people think:confused:

[zrpilot]

Originally posted by awsomeaussies
I'm running a EBC HD clutch so I think that will work. Money is an issue... but I figured might as well do it right the first time and hopefully I wont be left wanting more:p I'll look into the Port and Polish, but I heard that it doesn't help as much as people think:confused:

On the port and polish, I agree, unless you've got the cam, carb, and exhaust to make it flow!

Its like baking, all the right ingredients make the cake SWEET!

[oldskoolex400]

ive had too many problems with it not wanting to start if the battery is not 100% charged, my friend had the same problem on a few years ago on his 250ex, now the gt thunder box i havent heard anything bad out of, i would be willing to try it if i was wanting a rev box, me, i think ill spend my money on something else...........

[CHEVYZ]

Originally posted by awsomeaussies
I'm running a EBC HD clutch so I think that will work. Money is an issue... but I figured might as well do it right the first time and hopefully I wont be left wanting more:p I'll look into the Port and Polish, but I heard that it doesn't help as much as people think:confused: A good port and polish is the best money you can spend for performance IMO. It is not a waste at all, especially on a modified engine.

[dariusld]

Originally posted by CHEVYZ
especially on a modified engine.

I did my own mild port and port polish. I'm usually faster than similiar modified 400exs. The cam, port and polish, rev box, and high compression piston are a very good combo:)

[zrpilot]

Originally posted by awsomeaussies
I'm going to be building a 416, well actually a 415;) So far I have the Powroll 415cc bore kit. 87mm forged piston, 10.8:1 compression
Includes: Piston, pin, rings, circlips, headgasket, basegasket
I'm also going to get a Stage 2 Hotcam and a 450r carb. And I already have the HD studs... I know there not necessary with a 415, but I figured better be safe than sorry.

What I need some advice on... is what else should I do? Such as should I get a 3 angle valve job? Is there anything I'm missing? I'm thinking I'm going to have GT thunder install everything.

If you do all this and do it right (take your time and pay attention to the details) your 400 will be much faster!! It WILL surprise you!!

[awsomeaussies]

Just got a price on play porting... 250.00
Laz said it will make a difference, but I'm not sure if I want to spend that much:( I think I'll just have to crunch all the numbers and see what I'm willing to spend.

And 125.00 for his CDI

[awsomeaussies]

Also should I go with a 38mm or 42mm carb?

[j450rking]

i got a rev box from golden west cycle and it works good for me never had any battery problums or anything and i only paid $60 for it

p.s. if you have the porting done let me know how it turns out i am going to be running almost the exact same setup and it would be nice to see how it comes out befor i do it:devil:

[oldskoolex400]

get the porting hold off on the rev box......

[400exrider113]

i would get a hd cam chain while you have every thing apart

[zrpilot]

Originally posted by oldskoolex400
get the porting hold off on the rev box......
I agree! I think the porting in combination with exhaust, carb, cam and high compression piston will make more power then all of the above, but replace porting for CDI. And having the 1000 extra RPM is just not needed for me...

[04exking]

I reccomend my Big-gun rev box I love it. Just my 2 cents

[vett_09]

The purpose of the CDI is not just for the extra RPM's. Aftermarket CDI's regulate voltage better than stock boxes and produce a hotter spark. (CDI stand for capacitor discharge ignition) Aftermarket CDI boxes are more temperamental then the stock ignition systems that come from Honda. I haven't had any real problems with mine, but I know others have especially with White Brothers rev boxes. If you have the money, I would say get the port and polish over the rev box as well. But you will notice a difference with a new CDI.

[awsomeaussies]

Originally posted by vett_09
The purpose of the CDI is not just for the extra RPM's. Aftermarket CDI's regulate voltage better than stock boxes and produce a hotter spark. (CDI stand for capacitor discharge ignition) Aftermarket CDI boxes are more temperamental then the stock ignition systems that come from Honda. I haven't had any real problems with mine, but I know others have especially with White Brothers rev boxes. If you have the money, I would say get the port and polish over the rev box as well. But you will notice a difference with a new CDI.

Thanks for explaining what it is! I think I'm going to hold off on the CDI for now and get the porting:) Since I can add a CDI anytime.

[oldskoolex400]

Thanks for explaining what it is! I think I'm going to hold off on the CDI for now and get the porting Since I can add a CDI anytime.

good choice

[awsomeaussies]

I'll have to send the Hotcam to get installed too right???

[oldskoolex400]

if your sending the complete motor to them then yes, you will have to send the hotcam in also, it is relatively easy to install a cam though, but if you dont feel like messing with it send it also

[awsomeaussies]

Originally posted by oldskoolex400
if your sending the complete motor to them then yes, you will have to send the hotcam in also, it is relatively easy to install a cam though, but if you dont feel like messing with it send it also

Actually I was thinking about just sending the top end. Because they add quit a bit just to tear the top end off. So you need the whole engine for installing the cam right? If that's the case, I'm sure I can do it myself.

[vett_09]

Yes, you would need to send them the entire engine because they have to time the motor out and line up the cam to the piston position. Installing the cam is not very difficult. It takes longer to tear the fenders and gas tank off than it does to install the cam. Just make sure you do a vavle adjustment after the installation.

There are instructions included in the box, but if you need to use this video from the hotcams web site: http://www.hotcamsinc.com/index.cfm?fuseaction=cMedia.viewInstallationVideo&videoid=1
It shows how to install a single piston cam. (Not a 400, but it's basically the same.)

And if you need directions for the valve adjustment use this link:http://www.atvriders.com/articles/valveadjustment400ex.html

And don't forget, if you do only send them the top end, make sure you have the motor timed out properly. You can do major valve damage otherwise.

[awsomeaussies]

Originally posted by vett_09
Yes, you would need to send them the entire engine because they have to time the motor out and line up the cam to the piston position. Installing the cam is not very difficult. It takes longer to tear the fenders and gas tank off than it does to install the cam. Just make sure you do a vavle adjustment after the installation.

There are instructions included in the box, but if you need to use this video from the hotcams web site: http://www.hotcamsinc.com/index.cfm?fuseaction=cMedia.viewInstallationVideo&videoid=1
It shows how to install a single piston cam. (Not a 400, but it's basically the same.)

And if you need directions for the valve adjustment use this link:http://www.atvriders.com/articles/valveadjustment400ex.html

And don't forget, if you do only send them the top end, make sure you have the motor timed out properly. You can do major valve damage otherwise.

Thanks! I just printed out the valve adjustment instructions and I'll watch the video when I get off work. Thanks for letting me know about the timing and valves... because I had know idea. I guess I should learn how to do something while I'm at it:p

[PismoLocal]

My first rebuild I installed a new cylinder, piston, hotcam, 450r carb, clutch, and HD camchain in about 6 hours. It was the first time I ever tore into the motor. The only advice I have to give you if your going to do your own motor work is to buy a clymer manual and have patience.

[dariusld]

Another tip is when you put the valve cover back on, don't tighten those bolts down very much, just snug them in a criss cross pattern.;)
Did I miss something? Are those instructions, for the cam install, for the crf450?

[vett_09]

Yeah, it's for the CRF450r, but it's the only how to video hotcams has that I found. Still the process is pretty much the same for all single piston engines once all of the plastics and the gas tank are removed. I didn't use it when I installed mine, but it can't hurt to watch it.