Happytime Heat

Discussion in '2-Stroke Engines' started by trekfelix, Aug 4, 2009.

  1. trekfelix

    trekfelix New Member

    I built my first happytime kit today and i loved it, in ran great but it was sooo HOT! im using a 20:1 Mix, I dont think it would be a lack of lubrication.. So im not sure. Is this just normal

    Any input welcomed.


  2. yes these engines get hot.
  3. spad4me

    spad4me Member

    To keep your Air Cooled pre-mix lubricated happytime engine alive, use a good oil for air cooled engines.
    Do not stop at lights or anything with the engine running with no airflow over the engine for long . You will cook your engine.
    Do not close the throttle when coasting down hill, blip the throttle.
    This keeps the oil mixed with the fuel flowing to the bearings.
  4. fetor56

    fetor56 Guest

    Until it's broken-in only run your engine for a maximum 1/2 hr at a time & maybe even increase the ratio to 16:1......varying throttle speeds also help.
  5. if youre coasting down hill pull your clutch in.
    and idling at a light will not hurt your engine,the heat still leaves the engine threw the fins to the air.
  6. Thomson85

    Thomson85 New Member

    It's an air cooled engine, therefore it relies on the air to cool the engine via the cooling fins.

    So anything that prevents air to do this can cause the engine to run hot. As stated above, avoid long stops (red lights, stop signs, etc). Use the provided kill switch at such points. It's too easy to peddle 3-5 times and drop the clutch and start that baby back up. It's an internal combustion engine, it's going to get hot, there's fire in there, and on top of that the metal is cheap Chinese metal. I'm sure a small mounted fan near the engine could prove to help, but not much.

    Don't be too scarred that it gets hot. Ever feel your car engine after a drive? Try it. And thats liquid cooled (radiator).

    On the statement regarding riding it downhill, if it is a large hill just pull in the clutch and kill the engine. Why do you need the engine to idle or run while going downhill? Especially if you just let it idle, might as well kill the engine and let it cool.

    Your gas/oil mixture does matter, but so does your fuel/air mixture. Check for leakes around the carb using brake cleaner. If the engine dies when you spray it, then there is a leak (dont spray on air filter). A lot of people get confused and think the gas/oil mix controls running rich or lean. It's actually the air/fuel mixture. The more air that gets in, the hotter the engine will run.

    However, be sure to properly lubricate your engine. Personally I use 35/1 as recommended by thatsdax for breakin and normal operation. It works good for me thus far. But you have to find what works for you. Too much oil fouls your plug and oil will build up in your exhaust. Not enough oil and your engine will not be properly lubricated and can cause engine failure.
    Last edited: Aug 5, 2009
  7. arceeguy

    arceeguy Active Member

    Yes, you know that expensive Japanese or American metal doesn't get hot - just the cheap Chinese stuff. :dunce:
  8. Pablo

    Pablo Motored Bikes Sponsor

    My question is: What does your spark plug look like?
  9. HoughMade

    HoughMade Guest

    ...but it's a higher quality "hot" :ack2:
  10. juliman

    juliman Member

    hey check out my 'cooling fan' post in search
  11. Skyliner70cc

    Skyliner70cc Active Member

    How hot is it getting? It'll run best between 170-210 deg F. If your new engine is running too hot, adding more oil to the fuel as a percentage of total fuel volume will only make things worse. 32:1 is plenty of oil for a new engine. If it runs hot, consider adjusting your air/fuel mixture by raising the needle valve or drilling out the main jet.

    A cooling fan is unnecessary and unlikely to provide sufficicent cooling to make an impact.
  12. Thomson85

    Thomson85 New Member

    A cooling fan would only be sufficient if you plan to leave the bike at idle for long periods of time. During normal operation, even stopping at red lights, it should run in it's normal operating temp. A cooling fan won't hurt, but is not required. However, if you plan to leave your bike at idle, sitting still, then yes a fan might be enough to keep it at normal temps.

    I think some people don't realize that these are engines, in between your legs. If the heat is too much of an issue for your legs, I suppose you could fabricate some sort of vent intake with good quality plastic or sheet metal. Creating a channel for airflow to keep the engine cool, and your legs.