NC 30 Running In Advice

[dave1983]

Hi,
Just after some advice on running in an NC30 I have just re built.

When doing the engine rebuild I had the cylinders honed,installed new rings and shell bearings.

I have the Haines manual and it recommends 600miles at 6000rpm or below and the 600-1000miles up to 9000rpm I think (but I guess this is for a new bike).

Is this a little over the top or should I go with what Haines is saying?

Any advice very welcome!

Cheers

Dave

[Neosophist]

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

wont hurt to do it the book way at all but i do this method with my bikes

[bikemonkey]

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

wont hurt to do it the book way at all but i do this method with my bikes

Good read, makes perfect sense really

[dave1983]

Thanks chaps!

[lukemillar]

I used the Motoman method on my last two race engines and they haven't blown up. (well one did but that was user error!)
The problem is, you only get one shot at running an engine in so you will never know what it would have been like if you had done it another way!

[dave1983]

Yeah I had been delibirating about what to do. On reading the Motoman article it says that most of the running in was done in the first few miles and to change the oil after 20miles. I had already done 50miles using the normal running in procedure so I have decided to crack on with that as I guess it's not a good idea to mix them up. Also I havent ridden a sports bike for a few years so it's a good excuse to take it easy on the roads.Will defo try the Motoman method on the next project.

Thanks again for the help guys. Great forum this!!!

[Neosophist]

if all your other bearings and what not are stock and you changed the pistons / rings and shells then id say its already good to go.

the pistons bed in in the first 20 or so miles.

After that most manufactureres recommend varying riding for the first 1000 or so miles to let all the other bearings / gearbox / suspension etc bed in and not overheat any tight spots.

if im rebuilding a bike thats already been bedded in then ill just bed the rings in, check for leaks and ride as normal after that.

[Malc]

After that most manufactureres recommend varying riding for the first 1000 or so miles to let all the other bearings / gearbox / suspension etc bed in and not overheat any tight spots.

It's been said manufacturers recommend 1000 miles more as a way of encouraging you to take it easy on a bike you're not totally familiar with, or in other words to try and cut down on "brand new bike" accidents.

They cane the arse off them on the dyno at the end of the production lines, they don't need running in at all from new.

[Neosophist]

After that most manufactureres recommend varying riding for the first 1000 or so miles to let all the other bearings / gearbox / suspension etc bed in and not overheat any tight spots.

It's been said manufacturers recommend 1000 miles more as a way of encouraging you to take it easy on a bike you're not totally familiar with, or in other words to try and cut down on "brand new bike" accidents.

They cane the arse off them on the dyno at the end of the production lines, they don't need running in at all from new.

oh this thing again. i've heard this so many times but it's not true. It's just some mis-information passed on by people who think a good rev up at the factory will bed in an engine.

Yes engines are tested at the factory to soem extent (see below) but they are not broken in.

ive been on a few tours of factories where they make engines.. many of them these days are spun by air on the dyno machines and the machines connected upto the engines intakes and exhausts and other sensors determine the compression and vaccum and what not, maybe it was ford but i forget now but one of them said they can tell more about the engine build when its cold than its hot.

Only some of them are chosen for a dyno test with fuel, and this is usually no more than a few minutes, some engines are subject to longer tests to ensure quality but even then both these engines are run up for a shorter while under less stress than pulling a 2 ton car or couple of hundred kilo bike and rider along and even though they are revved to redline they don't get the amount of heat running the entire engine that a long drive on the road does, thusly even though they have been revved up high at the factory the engine doesnt get enough sustained heat and stress through it to make everythign thermally expand to its upper limit as it does when its in the vehicle and on the road.


not only this but the gear box / suspension, brakes / wheel bearings and 1001 other moving components are not stress / heat tested at the factory.


For an engine to be really broken in at the factory it would need a lot of hours and heat and varying degrees of load on it which just isnt feasable for any production vehicle. And you would still be left with all the other vehicle componenets besides the engien that when new might need a bit of time to bed in.

A tight bearing that is run at moderate load until its beeded in may well go on to have a good long service life, a tight bearing that is thrashed to super-heat before its had any time to bed-in will probably destroy itself.

since machining tolerances are so good and there is much less initial metal to metal wear on a new engine many newere engines do indeed skip the first couple of hundred mile oil change and just go with regualr service / inspection scheudle which is a testemant to modern day engineering but mfg still recommend a gentle break in of a new vehile for the reasons above.