400ex build

[skid572]

i got the bike used so i have no clue what has been done to the bottom end of the motor. I know it has a hot cams stage 3 cam in it,pro circuit t4 exhaust so while it is winter time and im not riding it im gonna tear it down and rebuild it paint,powder coat and polish things. here is a list of things for it

clutches,hd springs= ?
gasket set?
timing chain-crf 450
cam already has hot cams stage 3
piston not sure of size yet
jets ?
filter-uni
oil =?
oil filter
hd head studds =
carb 450r= yr?
clutch cable-92 Honda 250x = ordered
perch - msr aof= ordered
450r shocks
spark plugs ngk colder-DPR8Z
heli coils for came cover bolts= size??
spal fan

[skid572]

picks of project

<a href="http://s259.photobucket.com/albums/hh313/skid572/?action=view&amp;current=2010-08-09182725-1.jpg" target="_blank"><img src="http://i259.photobucket.com/albums/hh313/skid572/2010-08-09182725-1.jpg" border="0" alt="Photobucket"></a>
<a href="http://s259.photobucket.com/albums/hh313/skid572/?action=view&amp;current=2010-11-17164547.jpg" target="_blank"><img src="http://i259.photobucket.com/albums/hh313/skid572/2010-11-17164547.jpg" border="0" alt="Photobucket"></a>
<a href="http://s259.photobucket.com/albums/hh313/skid572/?action=view&amp;current=2010-11-17164559.jpg" target="_blank"><img src="http://i259.photobucket.com/albums/hh313/skid572/2010-11-17164559.jpg" border="0" alt="Photobucket"></a>

[CJM]

Answers are in bold:

clutches,hd springs= ?if you want a harder pull then by all means get heavy springs, I would leave them alone. if you must replace get some tusk ones from rocky mtn

gasket set? I like cometic, dealers more expensive but good.

timing chain-crf 450good, buy one from an 02 iirc, also replace the auto tensioner on the block and the cam chain guides while your in there.

cam already has hot cams stage 3 Unless you have a larger bore like a 440 then this is a total waste as it has to much topend and no lowend torque, switch to a HC 2 or 1 and sell yours, someone will buy it.

piston not sure of size yet 416 would be an excellent all around performer as would a 426. Go for 11:1 compression and you can run on 93
jets ? will depend on the mods
filter-uni good choice, I got one and love it. They dont come with oil so you gotta make sure you buy some

oil =? shell rotella 15w-40 or mobil 1 15w-50

oil filter stocks fine

hd head studds = GT Thunder, its worth having them bore it while they got it for the studs-thats what I did with mine

carb 450r= yr? 04-05 iirc

clutch cable-92 Honda 250x = ordered

perch - msr aof= ordered have one, even crashes dont phase it

450r shocks

spark plugs ngk colder-DPR8Z t hats the stock plug, you dont need a hotter or colder

heli coils for came cover bolts= size?? Do not helicoil anything! They do not last on the aluminum that the motor is made of. You want either real, solid type inserts (helicoil does make those) or drill and tap them to the next larger size metric or standard. The helicoils will not hold, trust me I know I had more than a few of them fail. They just dont bite into the aluminum to well. I would personally drill and tap if you can. 7mm would be best for 6mm or 1/4 standard. You can buy eveything you need at home depot or lowes

spal fan you want a puller type 3 inches diameter

[skid572]

thanks cjm as with the stage 3 cam this thing pulls realy hard on the bottem end hard to keep front down with leaning up over tank but im tearing it apart this weekend after i get the dang swing arm bolt out

[CJM]

Originally posted by skid572
thanks cjm as with the stage 3 cam this thing pulls realy hard on the bottem end hard to keep front down with leaning up over tank but im tearing it apart this weekend after i get the dang swing arm bolt out

You sure its a stage 3? They usually give you topend not lowend. But each machine is different.

When you get the swingarm bolt out, take it and use anti-seize lubricant and coat the entire thing. Or if you got the skills, drill a few holes and put a grease fitting on it and since the bolts hollow it will shoot grease all over everytime you grease it up.

[skid572]

We think it is i have another post on here about it somewhere. The bolt is beyond repair previous owner destroyed the threads on it so im just gonna get a new one and i have no clue what has been done to bottem end

[skid572]

found out what has been done to the bottem end it has a 89mm wiseco piston 12.5-1comp well this it looks realy good honing and new rings,port and polish on the head and a few other things mabye bigger valves idk yet

[CJM]

Thats a 440! Thats REALLY good! Make sure you get the headstuds done, otherwise you risk blowing a headgasket with that kinda compression. Since its such a high compression your gonna need to run at least 100 octane probably to avoid detonation.

You scored bigtime!

[PaRedneckRiders]

Nice score man.
Is the head gasket leaking in the first pic???

Ya If you plan on rebuilding it i would leave it pretty much like it is.

But personally would drop the comp ratio unless you want to run like 100+ octane.

Not sure if you had problems before or what gas you were running.

[skid572]

Yes that was a mix between cam cover and head gasket and I was running 93 with no problems it also had 3 layer thick head gasket and base gasket I don't mind running the higher octane I don't ride but 1-2 times a month. I think I'm just gonna do a few things to the motor not gona spend to much money into it. leaves more money for the suspention.

[CJM]

Really it ran good on 93? Thats awfully high compression and usually needs 100+ octane.

[trailrider894]

This thing needs A SERIOUS BATH!!!!!!!!!!!!!!!!!!!!!!!!!!!! Holy cow... thats the nastiest looking 400 i've ever seen on the forum. Clean it up and it'll look like new. I am telling you that a clean EX will run better and last longer than a dirty one...

[skid572]

Originally posted by trailrider894
This thing needs A SERIOUS BATH!!!!!!!!!!!!!!!!!!!!!!!!!!!! Holy cow... thats the nastiest looking 400 i've ever seen on the forum. Clean it up and it'll look like new. I am telling you that a clean EX will run better and last longer than a dirty one...

If your referring to the first pic that was the same day i got it and it will be clean hints the rebuild.

[honda400ex2003]

Originally posted by CJM
Really it ran good on 93? Thats awfully high compression and usually needs 100+ octane.

if indeed it has a stage 3 in it he may be right on the edge of the lowest dynamic comp to run 93 ok. hard to say though hes a lucky man thats for sure. I would bet with a stage 1 or 2 that thing would be pinging like a guy trying to do morse code. HAHA sometimes i crack myself up. steve

[2001400exrida]

Originally posted by trailrider894
This thing needs A SERIOUS BATH!!!!!!!!!!!!!!!!!!!!!!!!!!!! Holy cow... thats the nastiest looking 400 i've ever seen on the forum. Clean it up and it'll look like new. I am telling you that a clean EX will run better and last longer than a dirty one...

not necessarily true. 400ex aren't supposed to be all shiny and clean all the time, that just means that you wash it down everytime you ride and in some cases that equals putting it away wet, which is never good even if it does look clean!

i wash mine if it gets covered in mud, other than that the thing stays dusty, end of story.

[skid572]

atleast people no you actually ride it

[bherriman]

Originally posted by CJM
Really it ran good on 93? Thats awfully high compression and usually needs 100+ octane.



It wont have the 12.5 to 1 compression with his head gasket leaking...add in the stage 3 cam like steve was saying and he could prob run lower octane if he wanted.

[2001400exrida]

Originally posted by bherriman
It wont have the 12.5 to 1 compression with his head gasket leaking...add in the stage 3 cam like steve was saying and he could prob run lower octane if he wanted.

you would be suprised it doesn't drop compression hardly at all unless you have a giant leak in the head gasket.

just because oil seeps out doesn't mean you're losing compression. that's common assumption i hear all the time.

some head gaskets don't leak until you le the quad sit. i know mine will run fine all day and there won't be any leaks but when i put in the garage for the night, i'll have oil up on the had by the next morning.

[CJM]

Originally posted by 2001400exrida
you would be suprised it doesn't drop compression hardly at all unless you have a giant leak in the head gasket.

just because oil seeps out doesn't mean you're losing compression. that's common assumption i hear all the time.

some head gaskets don't leak until you le the quad sit. i know mine will run fine all day and there won't be any leaks but when i put in the garage for the night, i'll have oil up on the had by the next morning.

Thats because your head heats up, expands and then seals itself. Oil leaking out or such means you got a problem. Oil shouldnt leak out of any atv/bike engine! On a car when you see a leak its usually the valve covers or the oil pan (mostly the pan). Ignore one and it just leaks, ignore the other and it will cause all kinds of issues!

Oil shouldnt leak at all, thats what the gaskets are for! They seal the metal to metal contact and prevent leaks. If you put metal to metal lol it would leak like crazy.

Take a compression gauge and check the comp cold and hot and you will notice a difference. It should be rather consistent.

If I was to do a cylinder leak down test on a quad where oil seeped out/had a leaky head gasket I could tell right away b/c air would come out the leak and the cyl itself wouldnt have compression.

[trailrider894]

Originally posted by 2001400exrida
not necessarily true. 400ex aren't supposed to be all shiny and clean all the time, that just means that you wash it down everytime you ride and in some cases that equals putting it away wet, which is never good even if it does look clean!

i wash mine if it gets covered in mud, other than that the thing stays dusty, end of story.

Wow... You know i ride my atv nearly every time i get the chance. I have 360 acres to tear up and i do all kinds of crazy stuff. I just take my time to clean it to showroom. I ride it up and down the driveway to dry it out. It extends the life... end of story.

[bherriman]

Originally posted by 2001400exrida
you would be suprised it doesn't drop compression hardly at all unless you have a giant leak in the head gasket.

just because oil seeps out doesn't mean you're losing compression. that's common assumption i hear all the time.

some head gaskets don't leak until you le the quad sit. i know mine will run fine all day and there won't be any leaks but when i put in the garage for the night, i'll have oil up on the had by the next morning.



If oil is coming out..you are losing some comp. Period...that's all there is to it. I would like to know your logic on how you figure oil can leak out of the head gasket but air/comp cannot?

[CJM]

Originally posted by bherriman
If oil is coming out..you are losing some comp. Period...that's all there is to it. I would like to know your logic on how you figure oil can leak out of the head gasket but air/comp cannot?

Exactly.

[PaRedneckRiders]

Originally posted by trailrider894
Wow... You know i ride my atv nearly every time i get the chance. I have 360 acres to tear up and i do all kinds of crazy stuff. I just take my time to clean it to showroom. I ride it up and down the driveway to dry it out. It extends the life... end of story.

Why criticize someone on how or if/when he washes his quad. Whats it really matter, its his quad not yours.

Not trying to be an *** or anything but just let it go everyone has there own way of doing things

[2001400exrida]

Originally posted by CJM
Thats because your head heats up, expands and then seals itself. Oil leaking out or such means you got a problem. Oil shouldnt leak out of any atv/bike engine! On a car when you see a leak its usually the valve covers or the oil pan (mostly the pan). Ignore one and it just leaks, ignore the other and it will cause all kinds of issues!

Oil shouldnt leak at all, thats what the gaskets are for! They seal the metal to metal contact and prevent leaks. If you put metal to metal lol it would leak like crazy.

Take a compression gauge and check the comp cold and hot and you will notice a difference. It should be rather consistent.

If I was to do a cylinder leak down test on a quad where oil seeped out/had a leaky head gasket I could tell right away b/c air would come out the leak and the cyl itself wouldnt have compression.

I don't need a lesson on oil leaks.

And cars leak from the headgasket all the time i don't know what your'e talking about that is a common problem especially in older cars.

You will lose very little compression yes guys, but wha ti'm saying is alot of times when the motor is expaned you aren't losing any because there is no leak while running. I garuntee you that it's not a noticeable diff on my quad.

[CJM]

As a mechanic I can tell you that most cars do not leak from the headgasket. My toyota has 210k and I have the exact if not better compression specified by the manual, my buddys 86 bronco is the same way. My pos F250 in rebuilding now that has a bad headgasket cause it was overheated and the heads are warped. Still 4 out of the 8 cyls have perfect compression.

A headgasket shouldnt leak. What leaks most commonly on a car like I said is the oil pan and valve cover gasket.

Look man I aint trying to be a jerk, but you aint gonna win an argument about headgaskets and oil leaks when the guy your arguing with is a mechanic.

So lets just leave it be, oil shouldnt be leaking out of any critical gasket on any engine. if it is you need to figure out why and fix it.

[2001400exrida]

#1 I never said that oil should be leaking. An oil leak anywhere is not good.

#2 Headgasket leaks are common in vehicles, especially older cars or high mileage cars. (I honestly have no comment for the stupidity level of your thoughts about this).

#3 I would not take any of my motors to you, i do my own work.

#4 Leave it be.

i'm not saying that most cars have headgasket leak either, that's ridiculous i would hope that most cars are the road are running good. I'm saying, if there's an oil leak on the motore, it's most likely the head gasket. if it's dripping from below the motor then it's the oil pan but i'm talking about oil coming out of the head on a car, which is not uncommon.

[CJM]

Originally posted by 2001400exrida
you would be suprised it doesn't drop compression hardly at all unless you have a giant leak in the head gasket.

just because oil seeps out doesn't mean you're losing compression. that's common assumption i hear all the time.

some head gaskets don't leak until you le the quad sit. i know mine will run fine all day and there won't be any leaks but when i put in the garage for the night, i'll have oil up on the had by the next morning.

case in point...and thats all im gonna say man.

Oil wont almost ever come out the headgasket, coolant will. perhaps I mis understood you.

[bherriman]

Don't waste your breath CJM...this is the same guy that said HMF was stupid and didn't know how to recommend jetting, or use a dyno.

[2001400exrida]

you are making no sense? did i say oil leaks were ok?

did i say that oil should be leaking?

did i say that i was extremely happy with my oil leak?

no, but it runs fine, i haven't lost any noticeable compression and it's a very slow minor leak.


thank you please come again.

[2001400exrida]

Originally posted by bherriman
Don't waste your breath CJM...this is the same guy that said HMF was stupid and didn't know how to recommend jetting, or use a dyno.


haha, i never said HMF was stupid. why would you put words like that in my mouth?

also why would you tell cjm to save his breath when we are typing? smart guy you are.

I said that a 165 main jet is way to big for just an HMF slip-on. I know from experience in this matter.

I also referenced several links in that thread where they explained what the proper jetting size is. Those links were to the direct HMF website!

check your stats bherrimen, just because you build racecars doesn't mean you know how to suggest the proper jetsize for a simple slip on. it ain't no 165 broseph!

if anybody or their grandma asks me what a good size jet to start with would be for a slip-on modification. i would say a 152, that would put them real close.

thank you please come again.

[skid572]

OK PEOPLE LETS STOP THE ARGUING!!!!!!!!
This thread was started because im tearing down the quad and rebuilding it.This is the first atv build for me and i was looking for pointers and help not for ppl to start arguing over a dirty bike or leaky headgasket

[kt1148]

x2

[trailrider894]

Originally posted by skid572
OK PEOPLE LETS STOP THE ARGUING!!!!!!!!
This thread was started because im tearing down the quad and rebuilding it.This is the first atv build for me and i was looking for pointers and help not for ppl to start arguing over a dirty bike or leaky headgasket

I apologize for the washing arguement. I wasn't trying to start anything, i was just suggesting it. I didn't realize that they pics were pre wash and TLC, I apologize for that. I wish you the best of luck on your build and hope i can help if you have any questions. I am pretty sure i can answer most of them, but jetting is still a forgien thing since i am only EFI experienced until my EX.


I will say one thing about the headgasket thing. Just so happens my father is a 25yr ASE Certified Mechanic and a 25yr GM Master Tech. I called him up and asked him about the head gasket thing... He said and i " I have been working on cars since the 80's... and I can tell you that if ANYTHING is leaking oil, you have a problem." as far as old cars having leaky head gaskets. " Never seen an old car have a leaky gasket unless someone put it on wrong or left something out...... Or.... it is blown." If there is a leak in the gasket that is causing the oil to leak, it must be fixed. It will eventually progress so why not just "fix it now and be safe rather then fix and later and be to late.".

[CJM]

Yes, sorry back to the thread.

trailrider894 :D

[2001400exrida]

got lots of know it alls round here man, it's hard to get a word out without somebody already knowing.

hope your progress goes well, post up if you have any more questions.

[skid572]

a few pics of disassemble
<a href="http://s259.photobucket.com/albums/hh313/skid572/?action=view&amp;current=2010-12-14210254.jpg" target="_blank"><img src="http://i259.photobucket.com/albums/hh313/skid572/2010-12-14210254.jpg" border="0" alt="Photobucket"></a><a href="http://s259.photobucket.com/albums/hh313/skid572/?action=view&amp;current=2010-12-14210232.jpg" target="_blank"><img src="http://i259.photobucket.com/albums/hh313/skid572/2010-12-14210232.jpg" border="0" alt="Photobucket"></a><a href="http://s259.photobucket.com/albums/hh313/skid572/?action=view&amp;current=2010-12-14210214.jpg" target="_blank"><img src="http://i259.photobucket.com/albums/hh313/skid572/2010-12-14210214.jpg" border="0" alt="Photobucket"></a>

and a new clutch perch got here today
<a href="http://s259.photobucket.com/albums/hh313/skid572/?action=view&amp;current=2010-12-16201600.jpg" target="_blank"><img src="http://i259.photobucket.com/albums/hh313/skid572/2010-12-16201600.jpg" border="0" alt="Photobucket"></a>

[skid572]

o and a plus it already has a 8plate clutch in it not sure what kind tho. now all i need is the clutches,gaskets and rings.What do yall suggest for the rings

[CJM]

be best to use wiseco since thats who makes the piston. If you call them and tell them what piston you have you should be able to get the rings.

[skid572]

question where can i find the push button switch that is on this bike it seems to be popular
http://i163.photobucket.com/albums/t296/racequad450/atv228.jpg

[rubbersdown]

Originally posted by skid572
question where can i find the push button switch that is on this bike it seems to be popular
http://i163.photobucket.com/albums/t296/racequad450/atv228.jpg

thats just a dirtbike kill button wired as a starter. heres that exact one for $10 at motosport. http://www.motosport.com/dirtbike/product/TURNER-ENGINE-KILL-SWITCH-KX/?id=115407

[skid572]

well i got it all tore down now.when i was riding it before i always heard a clicking sound in 1st gear and i found out what was causing it the big gear for 1st has a tooth missing so now i need to find that gear. if any one has one laying around thats good i will buy it from you

[trailrider894]

Originally posted by skid572
well i got it all tore down now.when i was riding it before i always heard a clicking sound in 1st gear and i found out what was causing it the big gear for 1st has a tooth missing so now i need to find that gear. if any one has one laying around thats good i will buy it from you

Rocky Mountain ATV can get you one.

[skid572]

little update got it all tore down now i got a few pics just have to up load them. Got my new clutch cable today waiting on gasket set. still have to get a gear for 1st and a set of rings then i will be able to put it back together.in the mean time i will be sanding everything and painting i would pc but the local guy around here is expensive

[trailrider894]

Originally posted by skid572
little update got it all tore down now i got a few pics just have to up load them. Got my new clutch cable today waiting on gasket set. still have to get a gear for 1st and a set of rings then i will be able to put it back together.in the mean time i will be sanding everything and painting i would pc but the local guy around here is expensive

here is what you need to do. Use Eastwoods Extreme Chassis Black Epoxy Paint. It comes in satin and gloss. THey have a kit that includes primer. I used it on the bottom of a mudding truck once and it is still shines like new after being washed!!!

[skid572]

well i would if i liked black but i dont care for black.its not gonna be a rattle can job either.

[trailrider894]

Originally posted by skid572
well i would if i liked black but i dont care for black.its not gonna be a rattle can job either.

Well what color are you going for? You can get this paint for an HPLV gun with an activator. It is automotive grade.

[skid572]

im undecided on the color atm.I have a question about clutches it has the 8plate clutch in it but has the oem basket hub pressure plate.was trying to figure out what clutches to get for it

[CJM]

I think 8 plate with a stock basket is a sparks setup.