Break In Chinese Motor seized. [ break in speed - oil mixture ]

Discussion in '2-Stroke Engines' started by stowaway, Jul 21, 2007.

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  1. stowaway

    stowaway Guest

    excuse me as im not very mechanical and learning from scratch.

    Ive had my motored bike for a week. 80cc 2 stroke engine.
    ( 3AIT&viewitem=&item=290135951570&rd=1&rd=1 ) <-thats the 1 i bought

    I have ridden it every day for about 8 days. 3 hours a day. And today when i was riding it the engine shut off and seazed and i skidded to a stop. It would not kick over. Not even make a sound like it was. And when i tried it would just completely stop and not let the back tyre spin.

    i opened up the shaft that connects the chain to the motor and the cog seemed okay but there was little bit sharded metal in there.

    Any ideas what it is? there is 4 possibilities of what could have gone wrong:

    1] My stupid mate MAY not have put enuf oil in the fuel mixture.
    2] we just high flowed the exhaust.
    3] Riding 3 hours a day at max revs.
    4] Manufature problem.

    opions PLEASE. thanks.

  2. srdavo

    srdavo Active Member

    will the wheel and chain spin when you pull in the clutch? (will the bike roll?)

    tell us more about the metal you found by the cog? can to tell what it is from?

  3. davidsis

    davidsis Guest


    What are the chances of not enough oil??????? Ask buddy if he put oil in it or not, and does he lie?
  4. gone_fishin

    gone_fishin Guest

  5. If your mate is potentially 1/4 of the reason your ride failed then you need to either lose your friend or ban him from going anywhere near it. :shock: :grin:

    If it is a failed motor I know the guy that I get my motors from in oz offers a warranty of 30 days (i think) so it may pay to look on your suppliers site.

    How long have you had the motor if you have been riding it 8 days?
  6. Esteban

    Esteban Active Member

    Hmmm. Running a new engine for 3 hours per day for 8 days at max RPM's, sounds BAD to me !!
  7. Herrmanator8

    Herrmanator8 Guest

    did the piston sieze? maybe you could try to take off the engine head and see if the piston will come out.

  8. srdavo

    srdavo Active Member

    stowaway...before you start taking things apart.....make us clear on the symptoms

    will it roll?

    if your chain binding?
  9. stowaway

    stowaway Guest


    it will roll with the clutch in. But wont move at all with the clutch out.

    my mate isnt too blame he put 50:1 oil in. so thats not the problem.

    I took it to my dads workshop and the boys say it probably dropped a bearing. So im sending it back to the guy i bought it from coz the warranty lasts 30 days. (thank god)
  10. OldPete

    OldPete Guest

    I think 32 to 1 is what works best. Do not tell the vendor you were running 50 to 1...I sure would not.
  11. locoWelder

    locoWelder Guest

    here's your lagest part to cause it to fail.....

    3] Riding 3 hours a day at max revs.

    you MUST fallow all the break in procedures to have your motor preform the way its made to.Now if this was a type o on your part, then send it back asap but if this is true dont make the seller pay for your mistake.....Loco
  12. Herrmanator8

    Herrmanator8 Guest

    i would never run 50:1 in anything, i use 40:1 in weedwackers and blowers and thats it, 50:1 just isnt enough, and with that constant running with such little oil, thats just askin for trouble...

  13. OldPete

    OldPete Guest

    All the Tanaka 2 strokes are run at 50 to 1 from the get-go. :cool:

    Let us know how this shakes out OP.

    MB.edit Apples versus oranges comparisons may confuse MB's growing international readership, 50:1 is for more expensive, higher compression engines ONLY, and is in a NON Metrical unit.
  14. rcjunkie

    rcjunkie Guest

    50:1 is what caused your new engine to sieze. These engines should be run 16:1 when new (for about 150 miles about 2 tankfulls) and then switched to 20-25:1 oil ratio.

    These engines will run at full throttle ALL DAY long one broken in. However, when new you must vary engine rpm and load for a couple of tanks to seat the rings and get everything else inside the engine mated properly.

    So, when engine is new use 8 oz of oil (2 stroke aircooled oil) per gallon of gas. After engine is broken in you can decrease oil to 5.5 oz per gallon. Also, for added protection you may want to replace about 2-3 oz of the two stroke with degummed castor oil or buy a two stroke oil that contains caster in a 20-25% ratio to synthetic oil. Castor will help prevent oil breakdown since it can tolerate temperatures twice as high as straight synthetic.

    Now go buy yourself a new engine and keep the old one for spare parts.
  15. stowaway

    stowaway Guest

    new engine

    well he offered me a new engine at a discounted price.

    But I put in the amount of oil he told me.. Im a bit confussed on the ratio.. This is how i did it:

    50:1 50mls of Oil to 1 litre. Therefore 100mls to 2 litre of fuel.

    How much oil should i put in for 2 litres of fuel??

    Also. I use my bike as transport. It revs out at 42km/ph (about 23mp/h) thats pretyt damn slow. If im not to rev it out i gotta sit on 30km/h (18mp/h) that would s*ck.

    So im getting a smaller sprocket this time. hopefully i can keep the speed up without keeping the revs up.
  16. iron_monkey

    iron_monkey Guest

    I dont beleive you dont know that cruising on max revs day in day out will wreck the engine.

    It would wreck any engine, for that matter.

    Follow the instructions your supplier gave you. AFAIK the ratio should be 20:1 for a new engine and then when broken in 50:1.
  17. stowaway

    stowaway Guest

    max revs

    well it did cross my mind that it would f**k it.
    but i was hoping to get more time out of it. I was always in the process of getting a smaller sprocket. And traveling around 40kms a day at 30km/h didnt really interest me.

    Ive learnt now.

    Impatients = f**k motor.
  18. locoWelder

    locoWelder Guest

    then I suguest you buy a motorcycle,you can't push the bike motors like that..not just out the box stock,.
    I for one love the little motors out of China, and understand that I'm going to have to maintain them with alot of tlc,time and bloody hands but the outcome if worth it to me .
    if you wont care for them the way you need to then dont bash them!
  19. rcjunkie

    rcjunkie Guest

    50:1 ratio is fuel to oil ratio

    2 liters is same as 2000 ml of fuel

    Therefore 2000ml of fuel will require 2000/50 ml of oil which is exactly 40ml. I personally would add 50ml of oil to each 2 liters of fuel when new.
  20. npk1977

    npk1977 Guest