Break In Break it in!

Discussion in '2-Stroke Engines' started by istbenz, Oct 5, 2006.

  1. istbenz

    istbenz Guest

    about the break-in period. i've pretty much just been riding around on campus and i've run about half a tank through at 'polite' engine rpm's- how long do i need to be 'nice' to the engine? i'm just dying to open it up and ride for an hour. the paper work that came from dax said to take it easy for the first 500 miles. i don't even drive 500 miles in the car in a year! does this sound unreasonable to anyone else?

    also, has anyone besides dax opened up the muffler and modified it? i'm interested in increasing engine output and was wondering if it is worth all the extra noise.

    gimme your input.

    later :D

  2. Tom

    Tom Active Member

    500 miles is what I was told by many people, but that just seems like way too many.

    I personally probably went through 2 or so tanks of gas before I started revving it high and going on long trips.

    I modified my muffler. It became a little louder, but the power increase was substantial. The noise increase wasnt that much, and it still is quiter than my motorcycles. I would recommend it.
  3. istbenz

    istbenz Guest

    excellent! i shall begin the muffler operation tomorrow afternoon :evil:

    anyone else have input on the break in period?

    when i worked on aircraft engines the old guys always said how back in the day you had to break 'em in at low rpm. when i was breaking them in a few years ago, they said run 'em at high rpm's and keep it constant- that is don't futz with the throttle. so that's what i know!
  4. bamabikeguy

    bamabikeguy Active Member

    What I was told about the 40 cc engine (which is different than the 25 cc I favor) is that you are "seating the cylinder" during the breakin.

    The first two tanks I held a medium speed about 15-30 seconds, then up a quarter, back a half, in other words, varying the speeds and not holding it in any particular speed longer than 30 seconds.

    The third tank I held speeds for more prolonged times, in the 5-10 minute range, then down a half, up a bit, etc.

    Now, after about 10 tanks (300 miles or so) I can feel it gaining strength, just pulling the steep hill below my house quicker and easier each time.
  5. nogoodnic42

    nogoodnic42 Guest

    Hi guys and thank you Tom for setting up this forum. Some of you may reconize me from other forums, I have been around for a little while but by no means an expert, lol. From what I have been told by respected members in the moto world and it has worked for me on six bikes so far is: I do my inital start with a heavy 20:1 natural mix, run maybe a cup full through and then switch to a natural oil mix of 32:1 and take it easy for the first gallon or so. After that run it like you stole it if you are wanting to run synthetic it is ok to do so, I run 40:1 synth. This is not the "recomended" break in, it is what I have done on all of my bikes and they are all fine. Just my .02...Kelly
  6. etheric

    etheric Guest

    Cookie: What motor are you running and what break in technique did you use? I know you have spoken highly of proper break in technique, and seem to have more patience with this than some other riders do.
    I'm breaking in an 80cc dax right now. I've been running around 20 for about 40 miles, going easy on 'er and varying the throttle as much as I can (and of course 16:1). I've snuck up on 22mph accidently while on a slight decline but disengaged the engine and let 'er come back down a bit.
    I am willing to be patient, but is 500 really necessary? Is there a common consensus that the break in can be done properly without having to ride it for months with a painfully restrained throttle hand?
    Will there really be a noticable difference between the 300 and 500 mile mark during the break in?
    Augi: how many miles did you have on your first engine? What were your observations throughout the miles?

    I just have the sneaking suspicion that if i am all alone on a country road with 300 on the break in I may not be able to control than darn right hand...."noone is looking....they'll never know...."

    Maybe I just need someone to tell me that the two-stroke gods will strike me down if I get the throttle questions asked.
  7. Dr. J.

    Dr. J. Guest

    After you have riden for a while with the bike parked or while riding, spit on your fingehr and see if it bubles (sizzles) when you touch the side of the cylinder head fins. Water boils at 212 degrees. Most RC car engines are tested in this manner. If your spit boils, try slowing down or letting the engine cool. You will find on new motors run hard, the spit will almost turn to steam. You will feel a bubbling sensation on your finger tip when touching the cylinder head.

    There is an alternate method that I have been using recently. Go to your local hobby store that sells RC gas car/truck engines. They usually sell a digital temperature (heat) gage for about $30 on sale. The name brand is Duratrax sold through Tower Hobbies.
  8. gone_fishin

    gone_fishin Guest

    i had 110mi when the head-bolt popped out, i thought i had broken it in ok, but, with the new one, i too suffer from some serious self-restraint issues. since it was my 1st engine, i have no reference point, but i think i should have done a lil more slow-hand'ing.

    i'm gonna do 20mph for the first tank (60-80 miles?) of 20:1, then 30mph for the next tank at 20:1, then i'm gonna cut loose...maybe i should sacrifice an old weedeater to the 2-stroke gods, eh?
  9. etheric

    etheric Guest

    I appreciate the info augi but I'm not sure if you are helping! :)
    (now when i'm alone on that road i'll think "well augidog did")
    I don't think I want to be the one to make the observations of what happens between 300 and 500, but I'll go easy on her for a while and try to keep that monk-mindstate of patience.
    And thank you for the temp info, I don't feel inclined to touch the fins, but will see how water drops respond.
  10. gone_fishin

    gone_fishin Guest

    i did forget to add, tho, that at 100 miles i was getting superb performance, easy starts, no leaks or noises, the engine was in excellent shape excepting an unexpected mistake during assembly.

    my top speed with the mtb tires was 48mph according to my analog speedo :twisted: EDIT: analog speedo was way off, digital shows 26mph

    so, with my mucho-improved break-in plan, i'm betting i'll be good to go, maybe i'll get that other 8mph so i can keep up with cookie :wink:
  11. 247Jude

    247Jude Member

    I may have been too hard on mine even for the breakin, I have about 2000 miles on it and it looks like I may need a overhaul on it! It will still go like 50km/hour but it is black with oil, and gets all over my pants! Will be posting pictures later in the week, have it on my facebook!
  12. Skyliner70cc

    Skyliner70cc Active Member

  13. 350zdrftr

    350zdrftr Member

    I like that idea of a break in period, I have my own little way of breaking in a motor, but it does include full throttle for about 5seconds.
  14. Old Bob

    Old Bob Member

    This can be a controversial topic, but I'll throw my 2 cents in.
    but I follow this general guide line for two strokes:

    Cast iron/steel bore and plain rings get easy break in.
    Plain aluminum bore chrome ring get easy break in.

    Cast iron bore/steel and chrome ring gets run hard.
    Chrome bore and chrome ring gets run hard.
  15. Junster

    Junster Member

    What about the fact that guy is talking about 4 stroke engines? Think it makes a big difference? I meant to break my motor in slow I really did but.. Other than 2 very short runs and cool downs I gotta admit I broke it in kinda hard.
  16. alex

    alex Guest

    I went for 50 miles,under 15mph, for no more than 15 mins at a time with a 20/1 mix Engine currently has 4500 miles on it and still starts easy every time (even though I beat the spit out of it)
  17. Skyliner70cc

    Skyliner70cc Active Member

    break in is same regardless of whether its a two or 4 stroke. The rings seal the same way by cylinder pressure. Babying your engine is not the way to do it.
  18. superbee

    superbee Member

    what skylinder posted is how ive always known to break in an engine, but ive been kinda easy on my 2 stroke since everyone here preaches about that, ive never owned a 2 stroke so i did (well kinda) Ill probably break my next one in harder.

    and 500 miles????? ya thats alot of miles on a motor bike, IMO thats way past what a break in period would be for that engine, but thats just my opinion, no proof of that.
  19. 247Jude

    247Jude Member

    I would say some were about that! Takes me a little over a week and they start to kick, and I do over 300 miles a week! I have three so far and the second was by far the best using a hybid bike, trying to take it easy but not, any hills I would help it by peddling, on all start offs I would peddle, I would not torque it, but I did cruse one hour at a time, and did spare the throddle. Any hills or starts peddled with it! Gotta go close to 40 miles an hour now, except I sheered the mount bolts and fender tabs!
  20. Junster

    Junster Member

    Ok my last post here was a week ago I've put another gallon thru my motor since. Other than two very short run to warm and then cool completely. I did break it in pretty hard, 3d ride was about 4miles varing speed up to about 3/4. I could hear and feel the rings seat about halfway thru the ride. It's a 80cc HT Slant head from Zoom. I used 8oz of oil in the first gallon, 7oz in the second, I'm going to use 6oz from now on. My motor starts really easy. Looking in the ports the sides of the piston are very clean. It has done nothing but run better and better. I totally agree with getting the rings seated right.