Big Question!!! Please answer!

[BenHonda400ex]

Okay can someone please give me some links on how to bore out the sleeve and reassembling it!! I kinda understand it I just neeed to some of the nitty gritty little things that may not make it run right... I think I might do it myself only being 14 I don't know that much about the engine rebuilds but my grandpa is like a genius but I don't know if I can trust him.. How hard is it to do it? And what will it cost to get it bored out? Thanks!

[PaRedneckRiders]

just take it to the local shop and have them do it.
Limitations with a stock sleeve is pretty much 88mm (426)
If its stock bore now i would go 416 (87mm) go with an 11:1 high comp piston, but if thats what your doing dont get a cheap one i would go with wiseco or JE.
then i would get a good cam, hotcams are fine, stage 1 or 2 would prob be the best depending on your riding style.

Then later on down the road, or now if u have the cash get some head work done.
A good port and polish job to suite your type of riding will really bring the EX to life

[dirtrider77]

yea boring is not something you want to tackle yourself, especially since your trying to prove to your dad that the 416 is reliable hah

[honda400ex2003]

http://www.exriders.com/vbb/showthread.php?s=&threadid=449203


^^^ engine assembly and disassembly

get a manual download here:

http://www.sendspace.com/file/wcy9is

enjoy reading through them. steve

[BenHonda400ex]

How much do you think it would cost to get the sleeve bored by a shop or by la sleeve

[honda400ex2003]

la sleeve doesnt do them but a shop would be anywhere from 50-100 bucks depending on labor price and setup time. steve

[PaRedneckRiders]

yep id say 50-100$
Got my cr500 cylinder done for 30$ at a local shop but thats just cause i knew ppl there, they charged 55$ normally

[BenHonda400ex]

So when your putting back in your piston in the sleeve do you have to have anything in the sleeve like cuts in it or rings in it?

[CJM]

You gotta do it like this:
You go down to a shop or send it away to a shop and send your piston and rings with it.

They bore it out according to the piston. you get it back and put the rings inside the bore and checkt hem with a feeler gauge. You may have to file fit them to work properly.

Then you put it all back together and your good to go.

[BenHonda400ex]

I was watching a Rockymountain video on a 4 stroke rebuild but it was on a dirt bike but when they have just got back there sleeve there took like a ruler and make a cut in it do you know?

[CJM]

No idea what they did.

But putting it all back together is super easy, your piston (least wiseco ones) come with an excellent write up about where the rings go and how to space them and so forth.

[honda400ex2003]

No offense here, but it has to be said before going any further:

Whatever you do, DO NOT start taking it apart yet.

there seems to be alot for you to learn before you start doing this.

the taking apart and putting it back together isnt bad but there is alot to learn about before you start turning wrenches. make sure you have all the correct tools to do it.

torque wrenches, feeler guage, and a good socket set to name a few.

ok, now we can go on and help out.


Boring and such should be done correctly by the guys doing it as Flipper(CJM) said, you should just be able to get it off, take EVERYTHING needed (piston box and cylinder) to get the correct stuff done to it.

the manual will lead you through the tear down and such with the correct torque specs and all. steve

[PaRedneckRiders]

and they have a nice little arrow on them that should point towards the front of the quad.
The guy i bought mine off of apparently didn't know that and put it in backwards, smacked it off the exhaust valves which made to big notches in the piston and bent the exhaust valves.

[CJM]

YES, Super important to not do anything until you get your piston!

Its not that hard, your actually making it more complicated. Like scuba steve said (ha!) you need to have basic metric sockets and wrenches. You need 8mm, 10mm, 12mm, 13mm and 14mm and a good 3/8 and 1/4 drive torque wrench (borrow them if you dont want to buy them-I think autozone might lend them) as well as a 24mm to take off the valve cover caps to make sure your valves are adjusted right.

Follow the manual, ask us, its not that hard and by now ive done it so many times I can do the whole topend in an hour or less.

[416racer]

I think you need a 17mm also for the crankshaft bolt.

[CJM]

Originally posted by 416racer
I think you need a 17mm also for the crankshaft bolt.

yes, good call I forgot that one.

[3400ben]

6mm and 10mm Allen

Tip when you get your cylinder back clean the inside with a rag and transmission fluid to get the metal filings out.

[fromtheside88]

I don't know about you but what i have always found out when it comes to my dad being involved with anything on my quad it is better just to let him do what he thinks is right and then when he realizes he messed up go ahead and fix it lol. but i don't know if you really wanna go for that when it comes boring and all that unless you have the money

[dirtrider77]

Originally posted by fromtheside88
i don't know if you really wanna go for that when it comes boring and all that unless you have the money

do you always buy new cylinders when you rebuild bikes?

[honda400ex2003]

no you dont have to buy new cylinders. Depending on what size you choose though, you have to get a new sleeve to have pressed in. most of the time we only use 89mm sleeves. the rest can use the stock sleeve. I guess i shouldnt say the rest, up to 88mm can. steve

[dirtrider77]

Originally posted by honda400ex2003
no you dont have to buy new cylinders.

yea i know...he was just saying to leave boring alone...so i was wondering what he does when its time for a rebuilt and std. is no longer effecient ahah

[honda400ex2003]

i figured you did, it wasnt meant to be at you, just clearing up some stuff so he isnt confused. steve

[dirtrider77]

Originally posted by honda400ex2003
i figured you did, it wasnt meant to be at you, just clearing up some stuff so he isnt confused. steve

prolly still pondering over the 293520 pages of documents you left him to read (:

[honda400ex2003]

thats good... he can then become educated on the subject before doing anything with the machine. steve

[dirtrider77]

exactly....thats why i like you, not only do you tell someone where the gold egg is....you bring it to them (: hah

[honda400ex2003]

yup, it would take 3x as long to tell someone where it is when i can find it with a simple search where ever i need to. lol I even have some of this stuff stockpiled in threads so i can recall that thread and find it instead of searching. lol I remember keywords i search better than whole thread names lol. steve

[bencasey400ex]

Is it worth to get the cylinder bored out and 150 dollars for the 416 bore kit? Can you tell a difference from a 400 piped and cammed and a 416 piped and cammed?

[honda400ex2003]

imo it is! steve