Ok, I know this is a loaded topic right here, but I need help.

I bought a new KLX250s and brought it home today via a family members truck, and need some advice on engine break-in, as i've heard a million different things from a million different people. All my previous bikes have been pre-owned, so it never was a problem before.

I've heard from some people to just ride it normal, and open it up full throttle every so often, i've heard that you should follow the manuals break-in recommendations, i've heard that you need to just vary the revs constantly for the first 1000mi, i've heard that you need to vary the revs constantly but keep it under the manufacturer recommended rev limit, i've heard that you should ride it as hard as possible, hell, i've heard so many different things.

How should I really be doing this?

You might want to read this, http://www.mototuneusa.com/break_in_secrets.htm

The guy seems to know what he's talking about.

Quote from Batterypark :

You might want to read this, http://www.mototuneusa.com/break_in_secrets.htm

The guy seems to know what he's talking about.

mmm...very interesting.
I might try that myself next timt I'm running in an engine...can understand the theory behind that

Quote from Batterypark :

You might want to read this, http://www.mototuneusa.com/break_in_secrets.htm

The guy seems to know what he's talking about.

That is a pretty swish guide, I'll have to keep it for future reference.

I've seen that guide before, and it seems very good - I'd recommend that.

The worst thing you can do is tootle around in a high gear not using much throttle. Might as well just leave it idling for a month if you do that.

Quote from tristancliffe :

The worst thing you can do is tootle around in a high gear not using much throttle.

aka, Tristan racing in real life.

run the piss out of it.. im serious.

Brilliant guide Battery, it's something i've known about but never actually knew or understood why, there was also stuff I didn't know about like the the peices of metal in the oil messing up your engine.

I'd go 100% with this guide Sinko, especcially the oil change after the first while. Will put a big smile on your face once your really ready to let 'er rip.

I've read that guide before, and it makes perfect sense to me.

Unfortunately, here, it's unlikely you'll actually be able to get your new car with less that 20 miles on it, with stupid dealer test drives and stuff.

Dealers need to instruct their lot attendants to do this then (Former lot attendant here, lol)

Really makes me wish I'd gotten my car new... Oh well.

I put about 14 miles on the bike today, and just tried to avoid constant throttle, and then opened it up every so often.

How's that sound?

On a side note, it's really weird having a 6 speed tranny instead of a 5 speed (not counting neutral). I kept forgetting what gear I was in :P. Something to get used to I suppose.

Quote from 96 GTS :

I've read that guide before, and it makes perfect sense to me.

Unfortunately, here, it's unlikely you'll actually be able to get your new car with less that 20 miles on it, with stupid dealer test drives and stuff.

Dealers need to instruct their lot attendants to do this then (Former lot attendant here, lol)

Really makes me wish I'd gotten my car new... Oh well.

I got lucky. When we went to the dealership to purchase the bike, it was still in the crate, so I got a brand spanking new bike with only 5 miles on it

My way of running in a motor is vary the revs, don't let it labour & thrash the ring off it.

Modern engines have great tolerances so if you want to race it use the top end.

However - VERY IMPORTANT.

CHANGE THE OIL !!!!!!!!

500 km- oil & filter

1000 km - oil & filter

AND EVERY 5000 km - oil & filter.


Do that & it'll last for years, remember bikes combine engine & gearbox oil so it's cheap insurance changing it frequently.

Hmm interesting information, I'll give it a go when I buy a new car. And even Tristan approves, so you know it's true!

Quote from Roadie :

run the piss out of it.. im serious.

Exactly

Each time me and my friend rebuilt our CR250's we'd take them to the local corn field and basically give them hell for 20 minutes, after that they'd be running sweet as a nut.

Just make sure you have some decent oil and adjust it accordingly (rich/lean) to each stage of the menace!

However if you're new to the whole virgin engine game just take it easy, run a bit more oil and just pootle along blipping the throttle when and where you feel the need to.

Quote from 96 GTS :

I've read that guide before, and it makes perfect sense to me.

Unfortunately, here, it's unlikely you'll actually be able to get your new car with less that 20 miles on it, with stupid dealer test drives and stuff.

Dealers need to instruct their lot attendants to do this then (Former lot attendant here, lol)

Really makes me wish I'd gotten my car new... Oh well.

If you just would know how harbour workers that load cars to ship and are driving them, sometimes it feels they have floored it same moment they touch ignition key, with cold engine screaming and tires squealing cars run across harbour and sometimes then car is worth a small test drive in harbour workers opinion and here is a result, yet again piece of history is gone

Quote from Rooble :

run a bit more oil

No more than the maximum on the correct and original dipstick though - any more and you'll aerate the oil, and starve your bearings. Never overfill an engine.

Quote from tristancliffe :

No more than the maximum on the correct and original dipstick though - any more and you'll aerate the oil, and starve your bearings. Never overfill an engine.

Except if you have D24, 2-3cm overfill is recommend as it helps to get oil pressures up earlier, it is one odd design for engine that is for sure

Quote from Batterypark :

You might want to read this, http://www.mototuneusa.com/break_in_secrets.htm

The guy seems to know what he's talking about.

Wow, very controversing way to brake-in an engine. I've been discussed about this with a friend who prepare engines for competition and he told me that this is sligthly how he do. I was first surprised but now i understand why. Thank you for sharing such a good link Batterypark!

Edit: Oups i forgot: And what about the 2stroke engines (like aprilia rs125 and co.) ??

As long as you warm the engine properly (as with ALL engines), then yes. Perhaps run a few % more oil if you pre-mix.

Just to clarify, "warming an engine fully" means to wait until the temp gauge goes to its normal value, right?

Quote from shiny_red_cobra :

Just to clarify, "warming an engine fully" means to wait until the temp gauge goes to its normal value, right?

+5-10mins at minimum, imo. Well at least those with long alloy head.

edit: Maybe oil temp would be best indication really.

Yeah, oil temp - about 20 miles of driving. About 2 hours of idling.

Water temp really means diddly squat with regards engine warming.