Break in on a 03 400ex

[ajcroft]

I just bought a 03 400ex. I have heard several different ways to break in the engine. Any good suggestions?

[L.Vegas400]

some say break it in how you ride it.
some say bread it in by starting it and letting it warm up and completely cool down and repeat several times

i broke mine in at a medium pace, nto riding slow and not hauling @ss. it would keep up with a piped 400 at the dunes. i really dont think there is one deffinate way to do it, take all suggestions and do what you will

[Ryan]

It should explain it in the owners manual.

This is what I did and it worked fine....

1) Start the quad up...... Let it idle for 5-10 minutes (not giving it over half throttle).
2) Turn it off, let it cool down....... then repeat step 1 again....
3) start riding the quad..... don't not exceed over half throttle untill after 1 hour of riding.....
4) Go through the first tank of gas before you deceide to ride hard on it...

[ajcroft]

all the owners manual said was to avoid fast starts and sudden acceleration for the first 10 hours.

Right now I am just trying to take it slow and vary the throttle. I just wanted to see if there are betters and quicker was to do it.

[400exrules]

i heard that if u break it in a certain way, i think it was from mototune, then someone said his stock 400ex (broke in according to mototune) beats piped 400ex's (broke in according to manuel)

[ajcroft]

What type of problems will you have if you dont break it in long enough, or you break it in wrong.

compression problems?

[Ryan]

Originally posted by ajcroft
What type of problems will you have if you dont break it in long enough, or you break it in wrong.

compression problems?

The main process of breaking it in is to get the rings to seal correctly (I think). I've heard if it is done incorrectly, or someone just didn't give a chit and road the hell out of it, you can have loss of compression and damage your cyclinder.

I wouldn't worry to much about it. Many of my friends bought new quads, jumped on them, and road them to hell....... Problem free ;) .

[TRX_Thumper]

yeap i broke mine in according to mototune..let it idle and warm up for 5 minutes every time before i rode it...and gave her hell...and it has been known to beat piped 400ex's...

[ajcroft]

Thanks for the replys I appreciate it:)

[Ryan]

Is their a website for mototune. I wanna see what you guys are talking about.

[400exrules]

here it is



http://www.mototuneusa.com/break_in_secrets.htm

[Ryan]

Originally posted by 400exrules
here it is



http://www.mototuneusa.com/break_in_secrets.htm


Thanks.

Thats a great site, alot of useful info!

[PHIL_B54]

ajcroft, we need to persuade you to take off your carb and measure it for us and see if they did put a bigger one on the 03's

[250x]

hey, i just picked up my new 03 400 yesterday also. i had just sold my 02 on ebay. i did not break in the 02 but am thinking of doing some type of break in now. what do you mean bigger carb on 03's ????

[TRX_Thumper]

its the 04 ex's that are suppose to have the bigger carb

[PHIL_B54]

oh ya, sorry

[Martin Blair]

when me and my dad break in motors you run the [iss out of the thing, start it up once and let it cools, but honda checks the engine at the factory and runs them a bit so i has been started, then go out and drive it hard like you racing, rev it out get it really hot let it cool down and do it again, then go bakc and do valve clearence and change the oil and you should be set.

[250x]

WOW! you might be taking the word "break in" too litaraly:eek2:

[ajcroft]

A friend of mine hear somewhere that the 04's will have fuel injections! Any truth to that?

[250x]

no, the 04 is allready available this month. check out www.honda.com it shows in the specs that all is the same but a 38mm carb