2-Stroke break in


33 replies to this topic
  • Lowpro

Posted June 12, 2007 - 09:25 PM

#1

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. :thumbsup:
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

Posted June 12, 2007 - 09:42 PM

#2

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

Posted June 12, 2007 - 10:06 PM

#3

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

Posted June 13, 2007 - 07:05 AM

#4

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 ! :thumbsup:

  • 250Nasty

Posted June 13, 2007 - 12:16 PM

#5

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

Posted June 13, 2007 - 12:28 PM

#6

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

  • cuddies say YEE 925

Posted June 13, 2007 - 01:31 PM

#7

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


No.
.

  • kx_rider53

Posted June 13, 2007 - 02:12 PM

#8

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

Posted June 13, 2007 - 03:08 PM

#9

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

Posted June 13, 2007 - 06:16 PM

#10

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

  • cuddies say YEE 925

Posted June 13, 2007 - 07:11 PM

#11

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? :thumbsup: Just because there are no valves doesn't mean there are not limiters.

  • ringding

Posted June 13, 2007 - 07:16 PM

#12

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

  • gospeedracer51

Posted June 13, 2007 - 09:52 PM

#13

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

Posted June 13, 2007 - 10:34 PM

#14

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

  • mgw24

Posted June 13, 2007 - 11:35 PM

#15

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

Posted June 14, 2007 - 11:46 PM

#16

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

Posted June 15, 2007 - 04:44 AM

#17

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

Posted December 26, 2007 - 02:37 PM

#18

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

Posted December 26, 2007 - 08:11 PM

#19

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

  • SupermotoAbuser

Posted December 27, 2007 - 12:23 AM

#20

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.





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