Engine oil problems!

Discussion in '2-Stroke Engines' started by tythebuilder, Oct 18, 2010.

  1. tythebuilder

    tythebuilder New Member

    Hi guys, I bought a this chines 2 stroke engine about 2 weeks ago and ever since has been giving me really bad millage. I look back at the first time a put gas in it and I believe I put way to much. yesterday after coming back from a 2 minute ride I noticed there was black oil around the exhaust area so today I took it apart and noticed there was a good amount of oil in the exhaust. After taking that exhaust out i noticed the exhaust channel where it leads to the piston was all black and had oil. Then I took of the air filter cap and saw there was some gas at the bottom of the filter so I took the filter off and put my bike back in the garage. I took pictures of all the problems so you guys can get a better understanding what I am saying.

    And is it okay to have the HT muffler mounted like that with no extra support.

    Attached Files:

    Last edited: Oct 18, 2010

  2. GearNut

    GearNut Active Member

    An oily residue around the exhaust port is normal if you have even the smallest of exhaust leaks. A relatively dry yet oily residue inside the exhaust port is normal too. Excessive oil in the air filter element is very common on a 2-stroke engine that does not have a reed valve in the intake tract (your engine).
    A heavy oil/ gas ratio will not really damage the engine, just make things messy faster and make the spark plug work harder to keep itself clean and cause carbon build up inside the engine to build up faster.
    An excessively rich air/ fuel ratio can also create all of the above. What color is the business end of the spark plug in your engine?
  3. tythebuilder

    tythebuilder New Member

    The spark plug is black but seems to be working. Can a fuel ratio of to much oil cause bad MPG?
    How can I clean the air filter and do I need to clean the muffler because there was allot of oil in it, I mean its not full of it but when I took the bolts out that where holding it on, one was covered in oil. How do you go about cleaning a stock muffler. Thanks
    Last edited: Oct 19, 2010
  4. HeadSmess

    HeadSmess Well-Known Member

    cough cough, ahem....

    throw it on the fire...

    the exhaust, that is.

    dont get it tooooooo hot and the chrome wont burn off... but all that nasty oily goo inside will.

    a bit of oil residue is nothing...my things black with about a 2mm layer of dust n oil n just general crud :)

    but the carb always needs a good tweaking and in your case, tending toward leaner, ie...smaller jet.
  5. tythebuilder

    tythebuilder New Member

  6. Skyliner70cc

    Skyliner70cc Active Member

    Your question has been brought up repeatedly ad nauseam on this and other forums. You may wish to use the search function. What is best is an individual preference and there are many opinions to sort through.
  7. xxSLiMxx

    xxSLiMxx Member

    If your running at WOT most of the time its better to have more oil in your mix. So keep your mix at 25:1 or even 30:1 with a good synthetic oil, something highend.
  8. tythebuilder

    tythebuilder New Member

  9. AussieSteve

    AussieSteve Active Member

    As has been stated above, a 2-stroke (port-scavenged) engine, (no reed valve), will blow a little air/fuel mix back through the carb.
    Also, it's normal in a 2-stroke for the exhaust to be black and oily.
    On the fuel/oil mix, my recommendation is to follow manufacturers instructions. They probably know what they're talking about.
    The black spark plug indicates a rich air/fuel mixture. Once that has been sorted out, the mixture will burn more thoroughly, leaving much less oily residue.
    It's best to fit a strap or other support to the exhaust and not a good idea to hang it from the flange studs.

    Finally, you called your engine a 'HT'. The one in the pics isn't a Happy Time engine.
    A Happy Time looks like this:-
    HT Engine.JPG
  10. HeadSmess

    HeadSmess Well-Known Member

    he never said it was a HT... just mentioned a HT exhaust.

    no. dont put one on. unless you do have a brace mount whatever somehwere. youll break the exhaust port on what you have there. very light.

    and the stud spacing is slightly different.

    a reed valve 49cc 2 stroke. like the lil quad bikes etc....

    the reeds are @#$%$# on them. the carbs are $#^% on them...

    fix those two issues and theyll beat a HT anyday....
    Last edited: Oct 22, 2010
  11. adb140275

    adb140275 Member

    lean the carb out, theres a screw where the two lines enter... run 50:1 with a synthetic oil... the mileage sucks on those engines, though.
  12. keatonx

    keatonx Member

    My little 31cc is running terrible and makes a 1 foot wide puddle of unburnt gas. Unless it does this, don't worry.
  13. motorpsycho

    motorpsycho Active Member

    Wow, it amazes me how many people get into this hobby without knowing jack about engines, let alone 2 stroke engines. I would think that if someone was getting into this, they would know or want to know what they are dealing with as far as the engine, how it works, fuel-oil ratios, tuning, and the common things that go on with these things.
    One of the first things I always see is complaints about these little engines, but the thing is, they are CHEAP engines. They will never be as good as a high quality 2 stroke engine (like on a Yamaha dirt bike, chainsaw or weedeater). These engines are cheaply made with cheap parts. They usually will never run perfect right out of the box, you will always have to tune and adjust things to get them to run the best that they can. (no matter who makes the engine).

    A lot of people complain that the engines are junk because they don't run right, have low power, spit oil out the exhaust, spit gas and oil out of the carb into the air filter, bolts breaking, nuts stripping, etc. I think the majority of these problems is because of poor installation on the bike builders part. The other part is tuning, take the time and get to know how to tune the carb and you will be much happier. Take your time and install the engine with high quality nuts and bolts, with loc-tite. Make sure everything is adjusted right BEFORE you try to ride it. Also, go through the bike itself, check the bearings, brakes, wheels, tires and make sure the bike itself is working and put together right before you even mount an engine on it.
    Do some research and find the most common complaints about these engines, and you will soon learn that a lot of these things can be corrected if you take the time to learn how to do it.

    Think about it, you are getting a complete kit to put an engine on a bike for less than $200.00. A high quality 2 stroke engine will set you back far more than that, and that's just for the engine.

    So unless you are unwilling or not knowledgeable enough to get an engine running right and tuned right, this may not be a hobby for you. ("you" in general, not you specifically).

    One other thing I'd like to add is that yes, there are lemons when it comes to these engines, and some people do get them. Not every engine can be fixed, and is just a bad engine from the beginning.
    I can't speak on behaf of engines other than the Happy times style that are made for bikes, because I don't have any experience messing with the other style engines (rack mounts, 4 strokes, or electric). I am talking about 2 stroke engines that are specifically manufactured to go on bicycles.

    sorry, just my opinion.
    Last edited: Dec 17, 2010
  14. GearNut

    GearNut Active Member

    Very well said!
  15. adb140275

    adb140275 Member

    yes, very well said... i cannot stand when less intelligent people whine and complain when they dont know an engine from an elbow
  16. HeadSmess

    HeadSmess Well-Known Member

    then try licking it... :p
  17. motorpsycho

    motorpsycho Active Member

    I can do it, I have a very long tongue.