Rebuilt engine 'break in'

[81xsproject]

Until now I have never had to break in a new motor before. I have heard many different opinions on how you should run a new motor to break it in, but never anything about motorcycles. How should you drive a new motor?

This is about my buddies KZ, but seemed a 'general motorcycle' enough question to stay out of the 'other bikes forum.'

[mason79]

enjoy

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

[prometheus578]

"Nice link, Mason."

There's not a lot of member answers here concerning engine break in. Why is that?
Because we don't know!
Oh sure, we know what we've been told... but if asked to define just why it's one way and not another, we'd end up looking stupid.
Running a new engine hard is just as bad as baby-ing it too much.
Take it out and ride it. Not 90 mph highway, nor 25 mph city stop and go. get a good combination of the both, 'cept the 90mph part.
Expect the idle to climb. On just a ten mile test ride of new KLR650's, I have to turn the idle down several times before I got back; it loosens up that much. (That's new rings scraping the honing off the cylinder walls)



Well, I can't find anything wrong with his "unconventional" logic.
Engine break in is a science... and I was an psych. major.

Break in does primarily have to do with the rings. And yes, honing technology has changed over the years.
Aside from buying three new bikes, breaking them in and then tearing them down, (his method, conventional method and beat the livin' sh!t out of it), there's no real way to know.
I do agree that an oil change sooner may be helpful.
Synthetic oil: Even fully synthetic Triumphs require regular oil for break in.
Cool down periods are equally important.

Don't follow some sort of break-in proceedure, and as some members say, "Your mileage may vary."

[81xsproject]

Motoman discusses this for NEW engines and NEW honing patterns. How do you think that applies to what happens around here most, ie getting your cylinders bored and honed down at the old local machine shop and adding a wiseco kit? My guess would be that they don't have this new-fangled honing technology

[Crazcnuk]

Basically, take it out and drive it like your going to drive it.

I broke my Monte in mostly at the drag strip.


People have all kinds of methods for break-in, but you should just get out there and drive.

[DiverRay]

From school over thirty years ago,
1. have everything ready to ride BEFORE you fire it up the first time.
2. fire the bike, set the idle, check everything QUICKLY, and take the bike out on the road.
3. with bike in SECOND GEAR, run it up to redline, and chop throttle. Let the engine compression slow the bike down to about 25 MPH, then run it up again.
4. Repeat about three times, to "seat" the rings, and then ride the bike normally, but do NOT jump on it hard for at least 1,000 miles.
5. Do NOT run the bike for hours on end!! park and let cool at least 15 minutes every 30 to 40 minutes of running for the first 500 miles.

[Crazcnuk]

That is the same break-in procedure that has screwed people's minds forever.

If you do this you will get a perfectly broken-in vehicle for your GRANDMOTHER to drive.

The above is the typical factory break-in procedure, and it is great for people with no wrist muscles.

This is why you get a car from your uncle, as a teen, and you step on it a few times, and she starts blowing blue all over.

If you drive like your grandmother, use that procedure.

For everyone else, you have to break-in like you drive. If you like to do 1/4 mile runs, you have to include these in your break-in. If you want to cruise at 240kph, this also has to be part of your break in.

GM Performance,when I asked them about how to break-in my new 502/502 big block, asked me what I was going to do with it. When I told them it was going to be a bracket racer, they said break it in at the track. I asked if this affected the warranty, and they said no.

So the break in on the Monte was a 300km drive from home to the track, at normal speed limit, then a weekend of 1/4 mile passes, then back home. Repeat this about 30 times, with the occassional drive around town, and a smokeshow or 6, and you have a break-in procedure.

Keep in mind I rebuilt my first engine in 1978, and I have never had one fail.

[prometheus578]

Try these from a google search of "Engine Break In."

http://www.ntnoa.org/enginebreakin.htm

http://motorcycles.suite101.com/arti...in_controversy

http://www.dansmc.com/engine_breakin.htm

http://www.calsci.com/motorcycleinfo/NewBike.html
(Though I don't agree with his use of synthetic oils so early)

[ccogswel]

I have broke my engine in the same way as what DiverRay described. But I done it for 10-12 times to seat the rings. It had run great up till I had my accident.

But what you must keep in mind is how tight did you put the motor together? Now when I say tight I mean like main and rod bearing clearance's and ring gaps. If you went as tight as you could get away with you have to be careful not to build to much heat. Just use a good quality grade of oil and keep it cool.

If you use good parts when you build a engine you stand to have a good long lasting motor. But if you use old parts that have not been thoroughly checked you could have troubles. Like rod or main bolts that stretched even if it's just a couple thousandths it could bite you in the long run. Even old valve springs snapping in too, or the edge of a valve keeper kind of wore out and not holding. I could go on and on with little things like that. You can even have this happen with new parts as well but not as likely but I have seen it.

Just good luck with your motor. And remember this, if you take care of it, it will take care of you.

[79XS11F]

The only concern I would have with the HARD FAST break in is ..
- If your talking about a "rebuild" then the honing is not likely factory quality.
- Our bikes are in deed older so the castings and pistons etc are not really comparable to the new bike engines that he seems to be talking about.
- Also for a rebuild on one of our bikes we likely can not expect it to just fire right up and be completely ready for the FAST HARD break in. S**T .. By what he's saying .. by the time you get the carbs synced and confirm the timing ... it's too late.

I have always be told to break it in the way your going to use it. Factory break in is to cover all users and the way they will use the bike.
Rob

[wa407mpp]

Have to agree with Pro. on this one.

There is a big difference between breaking in a water cooled car and an air cooled bike. and as far as riding it fill out from the get go , a race bike can be run that way because it going to be rebuilt again soon anyway. If you plan on rebuilding it after every other ride thats up to you,but thats not a lot of return on your time and money.

[CruisingRam]

I have always been a bit easy with a new motor- so maybe I can catch something before it gets worse- a lose adjuster or something- so, as soon as I hear a noise, I can hopefully shut it down.

Also- our motors are old- and, there are lots of bearing surface that should have some oil put to them for a while. Seems like, looking in all the motors I have seens, that, early on, if there is some particulate matter in some oil passageway, you can seem to clean it out early on if you baby it a bit- when you romp on it, I think it doesn't have time to shake down to your filter.

Most of us tend to have maybe a different jug or head on it after a rebuild, and you have to retorque stuff most of the time after a break in, after a few heat/cool cycles.

I have had great success with the slow and easy break in, with graduated RPM runs as the bike motor had some hours on it.

never had a motor start blowing oil through the rings, that is for sure!

[Crazcnuk]

I've rebuilt air cooled too.


"Factory break in is to cover all users and the way they will use the bike."

This method is actually to cover the mfg's ass, by causing the minimum amount of warranty claims for faulty assembly and crappy parts!


That is until 3 days AFTER The warranty runs out....

[CruisingRam]

Well, the last time I had a motor I rebuild give up the ghost- it had six race seasons and had made me lots and lots of money- my old 440 in my race car.

Otherwise, my motors have lasted pretty much forever, as long as regular valve adjustments and tune ups are peformed.

Out of adjustment valves kills as much as anything with old motors of any kind, MC wise.

[Crazcnuk]

That and out of adjustment carbs...