[Lowpro]

What is the best way to break in a 2-stroke ? Some say run it hard to seat the rings and some say take it slow and easy for the first ride. :excuseme:
The dealer said he put synthetic premix in the bike. From what I understand,
you should use non synthetic for the break in.

[cuddies say YEE 925]

You are going to hear 30 different ways to break it in, because there are different ways for differnt people.

That being said, here is my method I have used for all 7 smoker motors I've rebuilt.

Pre-Notes:
*DO NOT use a synthetic blend oil for break in! A castor based oil is my weapon of choice. I use Castor 927
*Remember, you WANT A LOAD on the piston the break it in. The "idling" method I can't undernstand.

My trick is the heat cycle break-in. 3 times.

*1st cycle: Ride the bike. Go NO MORE than 1/2 throttle, with NO hard accelaration. Ride the bike until it is to operating temperature like normal, then park it. Wait until it is cool to the touch (on the pipes/radiators).

*2nd cycle: Take the bike out again, this time go NO MORE than 3/4 throttle. Go through all the gears, NOT WINDING it out- short shift. Stay away from hard accelartation. Get it to running temp, and park it again. Wait for it to cool down again.

*3rd cycle: Take the bike out, this time go through ALL the gears, but don't tach it out. You can go as hard as you want in any gear, but don't hit the revv limiter. Get to operating temp, and park it. Let it cool down one last time.

After it is cooled down the 3rd and final time, take it out and tear it up. Like I said, you will hear X different ways for break in, but this is my choice. I have 7 rebuilds, ranging from rings, to piston and rings, to cranks, etc. Never had a problem.

[SupermotoAbuser]

Hey man do two strokes have a rev limiter. The dude across the street from me says they don't but he rode in like the 70's. Ive screamed mine pretty hard and i didn't really feel an abrupt stop in rpms.

[Lowpro]

Thanks, will give your way a try. I have drained the synthetic premix that the dealer put in the bike and just mixed it with the Honda non synthetic for the break in. Thanks again. :thumbsup: 2-Strokes still rule ! :ride:

[250Nasty]

Hey man do two strokes have a rev limiter. The dude across the street from me says they don't but he rode in like the 70's. Ive screamed mine pretty hard and i didn't really feel an abrupt stop in rpms.

yes, all engines have a limiter, if not, it could blow cause they would be getting revved to the moon all the time,

[Roostin_Honda]

I'd lug it like start out in 3rd gear in stead of first. Is this a good idea?

[cuddies say YEE 925]

I'd lug it like start out in 3rd gear in stead of first. Is this a good idea?

No.
.

[kx_rider53]

Do this:
From Moto814

1) Assemble the engine properly and torque all fasteners to specs.

2) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

3) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

4) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

5) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

6) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), take the bike off the stand and put it in gear. Take it for a ride. During this ride you want to keep the engine under a load at all times. Do not coast. Do not let the bike idle. Do not allow the engine to stay at one RPM. Riding on a mild slope is fine for this, as is slightly dragging the rear brake the entire time. Do this for about 15-20 minutes. Then shut the bike off.

7) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

8 ) Re-torque the head and base nuts.

9) Go ride.

The cool-down steps are crucial to this operation. You must let the engine cool completely for the break in process to work properly.

Also, do the warm up procedure I outline here before EVERY ride. Your top ends will last much longer if you do.

-Steve

[gospeedracer51]

Hey man do two strokes have a rev limiter. The dude across the street from me says they don't but he rode in like the 70's. Ive screamed mine pretty hard and i didn't really feel an abrupt stop in rpms.

2 storke engines do not have rev limiters. There are no valves to float & bend.

[Way Fast Whitey]

but they do have some sort of govener so they don't hit 134,000 RPM and send the piston through the gas tank :crazy:

[cuddies say YEE 925]

2 storke engines do not have rev limiters. There are no valves to float & bend.

Hmm. Then what prevents it from revving so high that it no longer has enough time for the next stroke? :prof: Just because there are no valves doesn't mean there are not limiters.

[ringding]

hold the throttle open you can hear it hitting the limiter,

[gospeedracer51]

There is no ignition rev limiter on 2 stroke engines. There IS a limit to how much air the engine can pump based on a number of factors.

[SupermotoAbuser]

is it bad for the motor to let it hit that limit.

[mgw24]

Two-strokes do not have an electronic device that intentionally cuts off the electricity to the spark plug at a given RPM. As a previous poster stated: they don't have valves, so there is no risk of valve float. No limiter needed.

[tnracing132]

hold the throttle open you can hear it hitting the limiter,

that sound you are hearing that sounds like a 4 stroke rev limiter coming out of a 2 stroke is either you are running lean or your bike is about to seize, a good running 2 stroke will be like a solid train horn.

[CharlieT]

Ever hear a two-stroke that developed a sudden intake air leak?? I've seen data acquisition recodrings on a two stroke designed to be raced at a max of around 13000rpm, zing to over 20,000rpm in a minute fraction of a second.

What limits rpms on most two strokes is the porting and the pipe. Doesn't exactly limit its ability to rev, but limits its ability to make much of any power at all beyond a certain rev range. So there kind of real world rev limiters in that if you rev them beyond the power band and they just make less and less hp.

[2-stroker]

this is for new 2 strokes right? not for a new top end? im buying a bike with a new top end and i was wondering if i can start it up for a little while to make sure it runs without hurting the engine. because i wont break it in for another week.

[NO_FEAR]

I ride it like i stole it, not sure its thebest way to do it. I havent had a problem to date.

[SupermotoAbuser]

this is for new 2 strokes right? not for a new top end? im buying a bike with a new top end and i was wondering if i can start it up for a little while to make sure it runs without hurting the engine. because i wont break it in for another week.

It is for new top ends. So a new bike or one with a new top end would need to be broken in. Starting it and running it would be no problem. You just arent supposed to put a new top end in your bike and then ride the hell out of it right when you first ride it. Take the bike for a really laid back trail ride and dont rev it very high or fast. Just easy on the throttle keep from revving too high and youre fine. I just put a new top end on my bike and i just cruized if for like 2 minutes befor my race and then rode it hard in the race and it was fine. Try to break it in for like a half hour.

[SupermotoAbuser]

Oh and about the rev limit thing. 2 strokes don't have one in the ignition. The bike kind of stops making power and makes a lot of noize. Ive never revved it high enough to find out but i would imagine that at a certain point the motor would just stop revving higher.

[Gunning]

this is for new 2 strokes right? not for a new top end?

Guys, what about the big end?

If we mix up a non synthetic oil mix and then run the "new top end" in with this what r we risking on the main and bigends, I guess we will say that it wont be for very long but arnt we now mixing both synthetic and non synthetic oils:banghead:
I thought that was a no-no :foul:

[Norway]

some people use synthetics for break in, others don't. some people use the heat-cycle break in, others don't. some people use the "Ride hard-seat the rings" break in, others don't, and so it goes on and on and on....

bottom line is that you will not seize your new top-end if your jetting is good, you use a quality oil and you let it warm up before riding it hard.
it is true that the idle-only heat-cycle method is crap, you need to actually run the bike, but you don't have to baby it nor should you abuse it, ride it in some varied terrain, use the entire rpm range.

if it blows on break in you got something else wrong (jetting, airleak, crap in the bottom end from the rebuild, a faulty piston\ring and so on)

[07gixxer600]

Do this: From Moto814

1) Assemble the engine properly and torque all fasteners to specs.

2) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

3) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

4) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.

5) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

6) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), take the bike off the stand and put it in gear. Take it for a ride. During this ride you want to keep the engine under a load at all times. Do not coast. Do not let the bike idle. Do not allow the engine to stay at one RPM. Riding on a mild slope is fine for this, as is slightly dragging the rear brake the entire time. Do this for about 15-20 minutes. Then shut the bike off.

7) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.

8 ) Re-torque the head and base nuts.

9) Go ride.

The cool-down steps are crucial to this operation. You must let the engine cool completely for the break in process to work properly.

Also, do the warm up procedure I outline here before EVERY ride. Your top ends will last much longer if you do.

-Steve

Ive done this on all of my 2 strokes, with great results.

The reason for the warming and cooling on the stand is, sometimes in the first couple heat cycles the piston/ring can change shape slightly. You want that shape to be taken BEFORE you put enough load on the rings to seat them in. This is more so the case with forged pistons, but I do it with all.

The idea that some people have of "if you don't load it right away the cross hatching will no longer be sharp enough to cut the rings to seat" is not true, your rings will wear in regardless of the crosshatch, although im sure a good fresh, sharp hatch would speed this up.

Not using synthetic oil during break in is completely bs, the smartest thing you can do during break in is to leave your oil rato/type exactly as you plan to keep it and never change it. Whether its castor, synthetic, or just a plain petroleum it doesnt matter.

[slipp3ry]

rev limiter on my 2stroke? wut? .. the only thing limiting the rev is the physical time it takes for the piston to cycle, i mean the movement of the crank/piston can only go so fast.. but there is no limiter that i know of

[yz450fcranker]

i have a banshee ehm.. but i can buy aftermarket ignition boxes that increase a few rpms where possible so rev limiters are there and also real world stuff like engine just wont rev past 10k or 13k anymore cuz doesnt make anymore power
however when my banshee decided to rev alone possibly from an air leak it revved like at 16000 rpms tried turning it off it kept on revving pulled off the spark plug cap and it kept revving like a train going downhill i had to put it in gear and brake till it died

[SupermotoAbuser]

But im pretty sure that the ignition box you got for your banshee doesn't make it rev higher because of a higher rev limiter but because it has better mapping that will let your motor perform just a little bit better to get those few hundred rpms

[sc186]

It is a complete misnomer that "heat cycling" an internal combustion engine is somehow heat treating the metal. Heat treating takes place at temperatures much greater than a piston or ringset will EVER see during normal operation.

Bearings and seals dont 'break in' like a reciprocating piston assembly where there is metal to metal contact so there is no need to limit RPM's in that regard. Rings need to have a load placed on them via both heightened combustion pressures on the chamber side of the ring, as well as the case side to ensure that the ring seats-in perpendicular to the cylinder. This cannot be achieved at idle speed or putting around.

My advice: Warm the bike up without holding the RPMs at a fixed point. ie: light blips of the throttle, minimal idling. Once up to operating temps take somewhat of a sighting lap them let it rip. You will feel the bike open up and gain a whole lot of power over several laps as the rings seat and seal correctly. I've done this on every bike I've ever owned and nearly every top end I've done has had lterally zero blowby on the piston.

Anyways, there are as many break-in procedures as there are opinions. This is my experience gained from not only years of automotive and motorcycle experience, but also from my engineering background.

Cheers.

[jimmy123456789]

Old thread but I thought I would clear up this whole rev-limiter thing. 2 strokes don't have a limiter, they just reach a mechanical limit. For example, go outside and run as fast as you can, to where you're not picking up any speed, and try to keep picking up speed. You can't. Thats pretty much how a 2 stroke is.

[SupermotoAbuser]

Thanks jummy that is correct and a great way of explaining it