Break in period???

[mineralgrey01gt]

Some of you may know that I'm doing a rebuild with a stage 2 cam and 416 11:1 compression ratio piston. How long of a break in period is there, or is there any? Also with the 11:1 piston can I run 93 octane in it?

[barton1398]

warm it up at idle until it is to hot to touch onn the side of the engine kill it let it cool completely down repeat this three times then ride it like you stole it.

[ngates788]

when i did both my rebuilds i basically do like a dealer break in. full tank at half throttle.

[honda300EXtreme]

most everyone has there own opinion of how a motor should be broken in. so all i can do is give you my opinion.

i will usually give it 2 heat cycles at idle. let warm up untill at full operating temperature. let it cool completley, and repeat once more.

than i usually run a full tank through it. varying the throttle positions between 1/4 and 3/4. just to keep changing the load on the motor.

then change the oil and have at it.

[JOHNDOE83]

I would agree, that is the correct way to break in a motor....

[Honda#4]

When breaking in the motor remember the cam has to be broken in at above 3k according to hotcam specs. When I did mine I did 3 heat cycles altering the rpms but staying above the 3k for the first break in then it doesnt matter what you do, make sure to let it fully cool then do it again. After completing that change the oil cuz you will have metal in it, might actually be a good idea to do it once inbetween heat cycles.

But like other people have said everyone has a different opinion.

Personally I think doing it on a dyno is the way to go but not everyone can afford that.

[honda400ex2003]

i went by this:

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

3 sets of mx style practice lap type of riding letting it cool between. still running stong after a couple of years. steve

[mineralgrey01gt]

I should plug chop it too right? I'm assuming it's like a 2 stroke and plug chopping is a must. I mean you plug chop it the same as a 2 stroke, wot after break in then kill it and check it right?

[Honda#4]

For sure, just jet it rich alittle to start off and you'll be fine.

[lester985]

i give mine about a hour two or three times just cruiseing a round and then drive it like u stole it

[86 Quad R]

Originally posted by mineralgrey01gt
I should plug chop it too right? I'm assuming it's like a 2 stroke and plug chopping is a must. I mean you plug chop it the same as a 2 stroke, wot after break in then kill it and check it right?

most deffinately! :cool:

[Wheelie]

Heat cycling a forged piston is an absolute.


Here's how I break in my own machines, and those I rebuild for friends:

Start it, let it run at a fast idle until oil lines/engine is warm then ride at 1/4-3/4 throttle varying rpm for 10 minutes. Let engine completely cool and repeat. Change oil after second heat cycle.

Ride for about 30 minutes varying rpm with short bursts of WOT/high rpms (not banging rev limiter, just high revs). Let machine completely cool. Repeat 30 minute ride and change oil.

At this point I consider the machine broken in and right it/maintain it as I normally would.

[Rscarpantonio]

i just got done rebuilding mine to a 416 and took it out about a week ago, jsut go out there and give it hell and itll hold up, jsut remember to change the oil after the first tank of gas or so becasue of all the lil metal shavings from wear-in

[BlingyLTR450]

Engines dont really need to be drove special to brake in. Its older engines like old cars that need to be broke in from tighter tolerances. The first like 15 mins is the most important. Supposed to be a lot in the high rpm and do a lot of engine breaking mainly for the piston to seat good. Also use none sythnetic oil for break in.

[exrider12]

Your supposed to ride it like you normally would. No taking it easy. Your supposed to keep the engine revving and ride it like your supposed to. If I can find the article I'll post it up.

[mineralgrey01gt]

my 400 only knows 2 speeds, all out or stopped thats why i was wondering about breaking it in. I know how on a 2 stroke but it seems im getting a lot of different responses

[86 Quad R]

break it in as you would have with the two stroke but at a higher idle on the initial heat cycle to break in the cam. making doubley sure that you have the valves adjusted to spec first. ;) once you have completed a couple more heat cycles i would go back and double check the head bolts. :cool:

[mineralgrey01gt]

thanks randy, ill do it that way i believe. Im picking up a manual in a few days to see where everything needs to be adjusted to and such. Im ready to get this thing going!

[86 Quad R]

ya i hear dat... i been ready to get mine going spring is creeping up lol (http://ts4.mm.bing.net/images/thumbnail.aspx?q=1355826142215&id=57c4d1abc04b9769258a9d78ef27fc67&url=http%3a%2f%2ffunnydb.com%2fbig_231219125873.jp g)

[mineralgrey01gt]

lol i miss my 250r badly. When i get some extra money i plan on buying another. I miss the rip of the 2 stroke but i gotta say i do like the torque these 400ex's have

[86 Quad R]

yea i can appreciate the 4 strokers too... and a 400ex can be made to roost aswell. the last one i built was a 440 and i talored it for a 6'3"-300#er and it was a nice lil torque monster.

you do any head porting to yours whilst it was down? :D

[mineralgrey01gt]

im going to run it for a little while to see what kind of power difference i can get out of it before and after the port. I think i should be able to get some good gains from it. If it comes out good im going to start doing it on the side and for much cheaper than other places