how much break in?

[lilpoppy]

How much time do you guys think is enough before you can do some drag racing? How many hours or gas tanks?

3 tanks of gas...2 oil changes.

[honda350r]

I put my 425 together today and raced it all night at the thursday night drags! Just let it do a couple of heat cycles and let it rip!
Jim

[JD400exrider]

Originally posted by Crazy400exMan
3 tanks of gas...2 oil changes.

:confused: :huh :huh :huh

[hsr]

whats wrong with 3 tanks of gas and 2 oil changes??? as long as you break it in right there's nothing wrong with that

[White_Knuckles]

2 heat cycles and off he goes? I think that was a little risky, engine builders use a bit more caution and recommend a couple tanks to seat the rings etc.

[honda350r]

Call it what you want. I have built many 400exs and have had no problems! I have noticed the ones who are over careful have the most problems! Just my view.
Jim

[White_Knuckles]

Jim,

I haven't rebuilt but a couple engines and $ vs. fear followed "old school" break-in thinking. I could be flat wrong, but your comment about drag racing seemed extreme. That's a lot of stress on new metal but as with everything - experience trumps legend.

;)

[honda350r]

I don't think you are wrong at all. I guess I have a little more experiance with small engines than some others here . I just think some break in new engines in for so long they need to be rebuilt after break in .

If the engine sounds good and makes power easy then most likely it will live! If it is laboring to make power you had better find out why before something locks up..

One thing that is very important is to make sure you keep the RPMs over 2000 forthe first 20 minutes! That will insure that there is plent of oil in the top for the cam !

Jim


P.S The 425 I built on thursday had the oil & filter changed after cam break in! The quad rips hard!!

[White_Knuckles]

Jim,

My son has a brand new bike, what do you recommend as far as "new" break-in? The manual follows the old no steady RPM or WOT for 500 mi. or 3 tanks. I felt he could jump on it a little more than they suggest.

[JD400exrider]

I just thought three tanks of gas was a little long, however drag racing WFO after two heat cycles is probably a little risky. You will find alot of different methods on this site. After thinking how I am breaking my motor in. Three tanks of gas before running WFO drag racing is probably playing it on the safe side.
crazy400exman Your not far off in your thinking to play it safe. Just dont lug the motor or over rev it. Thats what I have heard.

On my new 416 motor i did two 15 minute heat cycles with complete cool down between them. I made sure it was warmed up before getting on it. I Keept the RPM's up during each cycle with no lugging of the motor. I let the back pressure of the motor also work to help break it in.
First 15 minute ride i did not go over 1/4-3/8 throttle running up and down through third gear varying the RPM's Cool down
The second 15 minute ride i went up to 1/2 + throttle. up through forth and fifth gear varying the RPM's Cool down and changed the oil and filter.

Third ride 45-50 minutes Riding it a little harder went up to 3/4 throttle with quick blurps of full throttle towards the end of the ride. Varying the RPM's in each gear.
Changed the oil and filter again and now i am ready to go on sunday for an all day ride. I will ride it for probably 50 minutes or so and let it cool down and then go for it.

I am new to this break in also Just my thought. What do you think on how I have done it.

Sorry for the long reply

[Sprttrx400ex]

I broke mine in for about 10-15 hours before i went all out with it, however it is good to let it warm up and then vary the throttle and basically ride like normal, just avoid long periods of time at wot or high rpms, but varyng the rpms is good for the break in. I also changed the oil after 10 and 20 hrs, the amount of metal shavings u see will amaze you, so i'd change it after 10 and 20 hrs to prevent possible damage.

[honda350r]

I will never break a engine in that slow...NEVER ! Do you guys think that racers have someone else break there race engine in for 500 miles or 10 to 20 hrs? I think not! a couple of heat cycles and I am good to go!

Just do whatever feels good to you.. I break them in fast and they go fast and last long!!

Jim

[honda350r]

Oh yeah, how come engine builders dyno new engines ? I don't ever remember a dyno shop telling me to make sure my engine has three tanks of fuel though it before it gets dynoed!

food for thought !

Jim