how do u know if your engine is overheating

Discussion in 'General Questions' started by andrewflores17, Mar 23, 2007.

  1. i was riding mine a little harder than usaual and when i tryed to kill it wouldnt dye when i lifted up the air intake it just kep reving and then when i was coming back home it died whenever i pulled in the clutch was this it overheating our something else

  2. I've wondered the same thing myself...just how *DO* you know your
    little 2-stroke is overheating, without actually seizing the piston and
    finding out the hard way.

    About the engine dying when you pull in the clutch, mine started doing
    that after a couple hours of runtime...turns out that cheap asbestos
    looking gasket that came with the kit to fit between the intake and the
    cylinder head gave way, and was letting in too much air.

    I made a new gasket out a thin cardboard and RTV silicone. Worked
    like a charm, and fixed that whole "won't idle" problem.

    BTW, that can be a serious problem, too much air coming in from a
    leaky gasket. Creates a lean condition... more heat, less lubricant... :eek:

    standard issue
  3. yeah it was that dumb little absetos sealer it just disengrated on me i am going back to a cereal box sealer a least they dont disegrate on you

    i wonder if their is a temapture gauge our something we could get for our bikes
  4. Patch

    Patch Guest

    what do you guys mean when you say cereal box gaskets? Do you actually cut out a gasket from a cereal box? how welll do they work...any help---much apreciated :grin:
  5. srdavo

    srdavo Active Member can make gaskets out of cereal boxes. (not exhaust gaskets)
    an old shadetree mechanic trick. cut out your gasket....coat both sides with a thin layer of grease & install. works as good as store-bought.
  6. Yup, quite literally the gasket is made out of a peice of cereal box!

    ...or any other kind of suitable, single ply cardboard you have lying
    around. In my case, I used a peice of the box a bicycle innertube
    came in, but that was just what was handy.

    Like the previous poster said, it works just as well as a store-bought
    gasket. IMHO, it's even better, because it's free!

    It also gives you that cool 'MacGyver' factor... :cool:

    standard issue
  7. RLK

    RLK Guest

    Note to self: The gaskets on these little motors suck so much that people use cardboard to replace them...


    I read on here that standard copper based form-a-gasket stuff works on both intake and exhaust. Just something I read on ther internet, don't sue me if that sucks as well.

    Re: overheating.

    Keep your gas oily. When in doubt with the fuel/oil ratio, add more oil.
    I live at 6000 foot altitude and always ride to higher elevations. This has tought me that rich air/fuel carburated motors won't run but lean motors will overheat. When less air is available dial in less fuel but not so little that you will overheat.

    Carburation is complicated. That's all I can say. Good luck.

  8. where do you live i live up here in colorado in denver and run mine at 32/1 to 25/1 what do you run yours at
  9. Guest

    Guest Guest

    Run it at 36 to 1 or 40 to 1. Synthetic is good idea. Buy it at Wal-Mart. The hyper expensive stuff is.....really expensive.

    The reason your engine was revving and running hot has nothing to do with how much oil you are running. Too much oil is as bad as too little.

    Keeping your gaskets in good shape will keep you from having a "lean run".
  10. jeffspeeder

    jeffspeeder Guest

    i live down here in the desert. is running a 50;1 mix good for it or should i stay around 30;1 - 40;1 ?
  11. Guest

    Guest Guest

  12. azbill

    azbill Active Member

    it was recommended to me to run 20-25:1
    it will help keep it a little cooler when it gets really hot here (desert)
  13. jeffspeeder

    jeffspeeder Guest

    really cuz someone told me that i should run like 50:1 and 40:1 to break in and thay said running to much oil mix will be bad for your motor leaveing a black build up on it. is it true?
  14. Hugemoth

    Hugemoth Guest

    It's not true that running more oil in the fuel will make the engine run cooler, in fact it's just the opposite. Oil makes the fuel slightly more viscous so less of it gets through the jets, making the engine run leaner and hotter.

  15. Guest

    Guest Guest

    You are correct sir! More oil=leaner fuel mixture.

    Ultralight background?

    Man, you sure don't want one of those to go quiet on you 100'AGL right over the trees at the end of the runway approach! Made it by about a foot. :shock:
  16. Hugemoth

    Hugemoth Guest

    I've been flying PPCs for 10 years now, Rotax 582. For those who don't know what a PPC is, here's a link to a pic I took of a friend during a flight around the local mountains.

    Most ultralights use 2 stroke engines because of the power to weight ratio. The engines are very expensive, over $6000.00 for the one I use so we want to take care of it.


  17. Guest

    Guest Guest

    That's the same engine as the one we use in the two place trainer (fixed wing) my Dad is a BFI.
  18. Thejman

    Thejman Guest

    I think i would shit myself if one of those engines quit on me mid flight. Then again, it would be like a 2 seater airplane just glide, if you could find a spot to land.
  19. Guest

    Guest Guest

    Well, like bicycles, planes can only "coast" so far. The difference is when a bike is done you get off and push, when a plane is done, you hope you find a good place to "quit coasting" and that you can walk away. :shock: :sad:
  20. rcjunkie

    rcjunkie Guest

    Lots of fallacies posted, some already corrected.

    Yes, more oil equals leaner mixture. Anything that dispalces fuel (such as oil) results in less fuel per same unit of air...e.g. leaner mixture

    For a set air/fuel mixture, increases in altitude result in a richer mixture. If fuel jetting is kept same as you increase altitude, you have less partial pressure of oxygen, meaning that the decrease in 0xygen with same amount of fuel results in a correspondingly richer mixture (relatively more fuel for given volume of air).

    The increase in altitude is why airplanes have mixture lever(s) that allow you to lean mixture as you increase in altitude.

    If mixture is appropriate for a given altitude, you still will lose 3% horspower for each 1000 feet gain in altitude. At my altitude of 6800 feet, my loss in horsepower is about 20% compared to same engine at sea level. This is why I need a 48-50 tooth sprocket to maintain speed going up steep Colorado Hills.