142f black oil

Discussion in '4-Stroke Engines' started by skyash, Dec 16, 2015.

  1. skyash

    skyash Active Member

    i just got a 142f 49cc and it get black oil really fast .are thay like that ???

  2. Just you're engine breaking in bro, run her thru her paces for a tank of gas then change it out every other tank after that 2X.. 10w-30 non synthetic you can switch later after the break in period. Lots of guys on here always talk about this lol
    Good luck and have fun.
  3. skyash

    skyash Active Member

    Thanks it's been good till now. The chain in the gear box come off I don't know y. So I am stuck now all looks good in side but the chain is loose eny idea
  4. KCvale

    KCvale Motorized Bicycle Vendor

    Good advice and I suggest the best synth oil you can find after the first tank for engine longevity.

    Simple really, when you check your oil, if it's dirty change it ;-}
    figure every 25 hours of operation time as you can't go by miles.

    This is a handy gizmo for run hours and engine RPM.
    These are only $12 but only good for about a year and does not have replaceable batteries.

    I find a turkey baster works great for this. Just suck out the bad and squirt in the good from the oil filler.

    The chain broke in, now it's loose, there is no way to adjust this, you just have to buy another new chain and repeat.

    Or ditch that transfer case and get an adjustable belt drive.
    Or if you'd rather I have a couple brand new ones you can have for cheap as I won't use them, ever.
    E me.
  5. skyash

    skyash Active Member

    thanks i will look in to it
  6. HeadSmess

    HeadSmess Well-Known Member

    let me guess... you got it new and took it very easy, in case it was damaged as you broke it in?

    experience shows that gentle breakins cause damage.

    if you load them down, run them at full throttle with the brakes on so hard it can barely rev, the rings actually get a chance to bed into the cylinder bore. after letting them idle to a warm up...without feeling the urge to blip the throttle like most people do when starting an engine.

    just start it, let it idle by itself til warm...then load it up as much as possible.

    this only takes about ten minutes, tops. after that...use it as normal.

    if any thing DOES break at this point...you got a lemon. look at the warranty card.

    then you dont get any nasty blowby products contaminating your oil. your piston skirt remains clean. power is increased as compression is retained... the engine lasts longer. the valves tend to seat in better, the cylinder hone marksare smoothed off but remain, retaining oil and keeping the rings/skirt lubed up. blah blah, yarda yarda.

    also, replace the oil at least 3 times in the first few hours of operation. dont bother with synthetics, just plain old 30W engine oil. especially on the initial break in!

    ten minutes of aluminium and steel filings will destroy things, so imagine what 5 hours of gunk can do.

    after all the shiny glitter stops coming out...its good to leave and change every 25 hours or so.
    cheezyguy5 likes this.
  7. 45u

    45u Active Member

    Rings do not bed in they set. Been building motorcycle engines for 40 plus years and before I ever run any new motor I heat cycle it 3 times. I know this works as I have motorcycle engines I have built with well over 100K still running fine. Proper break in is very important for the first 100 miles. Do it how ever you want I do it they way I have for years.
  8. KCvale

    KCvale Motorized Bicycle Vendor

    Pretty much the same here.
    Warm it up and take it for a few laps around the block and bring it back in.
    Make whatever adjustment may be needed and do it again.

    Once everything seems right a long hard ride and if everything still seems right an oil change before the customer ever sees it.
    That has served me well so far but there is also an idiot or two...
    I am talking somebody so stupid they should never operate anything on the roadway and have no clue about what maintenance means.
  9. 45u

    45u Active Member

    I let my engines idle with out any load till they get where it is uncomfortable to touch. Then I let it cool all the way down and do that 2 more times. Like to get the rings to start setting before I put any load on it. Been doing it this way for over 40 years with out a problem even on my 2cycle RC buggy engines with out a problem so I am not going to chance. LOL
  10. HeadSmess

    HeadSmess Well-Known Member

    you will have to explain just how rings "set".

    considering a ring never sits still during operation?

    and what benefit "heat cycling" has.

    considering that all internal parts are factory "heat-treated"?

    i like this picture, it shows how a piston SHOULD look when the engines "broken in" properly.

    note the carbon on the top...but nothing on the sides... well sealed rings.

    whereas this is an example of a piston not broken in properly... the one in the foreground, anyways.


    same pistons, same engine even...just broken in differently.

    i much prefer the ones that seal properly rather than suffer "blow-by"
  11. 45u

    45u Active Member

    Sorry seats in. Do you know why you have a crosshatch on most cylinders????? One to hold oil and to help the rings seat. If I had time to show pictures of all the pistons I took out of motors I built would take me two days or more. I am always building a Harley motor for someone or motorcycle motor and have not been with out at least one I was building for 40 plus years. Been know to have 15 or more going at one time. A few of my machines and some gauges. When it comes to Harley s I can balance the crank, rebuild the rods and MUCH more and been doing it for 40 plus years as well as many other brands of motorcycles. Most of my living has been make working on motorcycles of all brands. Do you know the best piece of metal to machine do not care what they did at the factory??????????????? One that has been sitting out and the weather for years as only gets better with age and MUCH harder. Do the research and you will see if you do not trust my word.




    Last edited: Mar 12, 2016
  12. 45u

    45u Active Member

    This is how I work on my rig when I do not take the sidecar off. She is my only transportation as I hate a cage!!!!!!!!!!!!!! Other then when I had children been that way for most of 45 plus years. Buy the way do some research on heat cycling you might be surprised.

  13. HeadSmess

    HeadSmess Well-Known Member

    done plenty of research on "heat cycling", it means zilch, so i am surprised!

    that people fall for it...

    yep, im all too aware of why they crosshatch cylinders. done properly. with correct break in, and the correct ring/cylinder wall material combination, they usually stay visible for... the life of the engine. cast iron is the exception, that stuff leaves nasty ridges at the tops of a cylinder, they even make a tool for removing said lip.

    they (used to, when companies like cincinnati made machine tools properly) leave (rough machined) castings out in a paddock for years before taking the finishing cuts.

    nothing to do with hardness, everything to do with released tensions in the casting (once the hard, outer, sand filled skin has been removed) having time to normalize. its common practise in precision machine work to leave castings alone to "do their thing"

    doesnt happen too much these days, everyone wants it NOW!

    picture time huh?
    Photo0251[1].jpg Photo0251[1].jpg
    just having a go at cutting a gear with this new-fangled software i got... generated involutes with a slit saw, not using a formed cutter.

    oh wow its hard to post pictures now... or is it? why did the upload file option just appear? after posting? hmmph.
  14. 45u

    45u Active Member

    Evidently you did not do very good research and do not have a clue about atoms. But whatever you are correct and everyone else is wrong??????????????BS
  15. HeadSmess

    HeadSmess Well-Known Member

    so, your harley uses lapped aluminium piston in a chrome-plated brass cylinder, and is two stroke, and runs on methanol? the only engines that require "heat cycling" are small nitro engines. and theres a reason they dont make lapped piston/cylinders with much more than 20mm bores...

    strange, i google heat cycle, the first hit that pops up says what i say, heat cycling is nonsensical in ringed engines.

    then there was a lot of hits for heat cycling tyres...

    then the occasional hit to harley forum boards where people that dont know much postulate the theory that an engine needs heat cycling to "heat treat" its internals... ignoring all the facts about metallurgy in the process, of course.

    but then, harleys are just glorified industrial engines stuck on two wheels.

    but what would i know? i couldnt tell a flourine atom from an argon atom... apparently:D

    must be all the actinides and lanthanides ive collected, making me fuzzy in the brain.

    cmon, mr chemist, tell me about the atom :)

    or tell me about what percentage carbon turns iron into steel... and then how much more carbon is required to go from mild steel to tool steel.

    mehanite? austinite? pearlite? all the same stuff... oh, and so is cementite... so what are they?
  16. 45u

    45u Active Member

    Whatever! I am over it and I only thought my spelling was bad! I do not lap any cylinders or pistons! Harley s are not nickle seal. I bore and finish my cylinders to .0002 so they need nothing but breaking in when I am done. You are one up on my as in 45 plus years of machining I have never heard of lapping pistons and cylinders is this something you came up with would not surprise me!!!!!!!!!!!! :eek:You can lead a horse to water but you cannot make them drink.
    Have a nice day I am.

    PS My Harley has over 116,000 on her all but 5 states and has 5 provinces. It is my only transportation just the way it has been
  17. Old Bob

    Old Bob Member

    Nitro engine cylinder liners are lapped. Been done that way for 80 years or so.

    heat cycling after machining does nothing, any heat treating, including cold stabilization, should be done BEFORE final sizing to be effective.

    Break in is determined by a few thing such as plain bore vs chrome bore, roller/ball bearings vs babbit.
    On M4 Hondas I recommend a gentle break in for the first hour, its a plain bore diamond turned, you need to work the whiskers off gently, on a chrome bore 2 smoke with roller bearings no break is needed and it should not idle and should get full throttle blasts to seat the ring.
    My 4 stroke Honda engines run over 16,000 rpm so I'm sure I know nothing.
  18. HeadSmess

    HeadSmess Well-Known Member

    they have been lapping for hella long time now... things like diesel injector pumps, high speed bearings/bushes, flat surface plates...the list goes on.

    im not sure nitro engines have even actually been around for 80 years...close to it but :) small IC engines have been around since the (very late) 1800's.

    hmms, i read about this only a few weeks ago...




    halfway down, first commercial glowplugs circa 1947... or 69 years ago.

    the smell of burning ether, kerosene and oil is so much nicer than the eye stinging reek from nitro engines :) shame its so hard to get hold of!

    and these days, electric is overtaking everything :(
  19. skyash

    skyash Active Member

    True that even 5 percent in my 66cc made my eyes burn when you stop at lights
  20. sbest

    sbest Active Member

    "Heat Cycling" has some value to get gaskets and sealers to set, with bolt retorque between cycles, but I am a "run'em hard" fan. Like Headsmess, I've torn down shortly after break-in (for various reasons) and looked for the carbon his pictures show. Light use on break-in does not seal well on roller bearing chrome or nikisil engines. I think Old Bob's comments are right for old school cast and babbit engines and KC Vale's break in is pretty much how I do it, 2 stroke and 4, in practical terms.

    Awesome gearcutting Headsmess. When cutters were not available I've used a custom ground flycutter. You know how much fun that is.

    Finally, to help with logic here, I'd like to offer this PDF link: