losing power up hills!

Discussion in '2-Stroke Engines' started by Ty, May 8, 2007.

  1. Ty

    Ty Guest

    hey, first time on the board.

    my engine is a 48cc chinese and i've probably done about 40km on it. It was going well for the first 30km and now its really struggling up hills to where im flogging my legs on the pedals to keep it going.

    i did leave the fuel line on a few times after use, which i know is a no no but i forgot! This caused some oil to trickle out of the muffler. could this be related to my problem?

    i have cleaned out the carb and it looks ok. gaskets look ok too.

    any ideas?


  2. Guest

    Guest Guest

    The 20/1 fuel mix will kill a plug fast, go to 40/1 and a new plug and let us know if that helps.
  3. Dockspa1

    Dockspa1 Guest


    Ok Joe,
    Straighten me out here. A 40/1 mix runs cooler or hotter than a 20/1 mix?
    Wouldn't it be the more lube included the better the protection but the more the gunk the worse the plugs?
    My Brain Cell Hurts!
  4. SlicerDicer

    SlicerDicer Guest

    I thought the ratio was 50:1? Well maybe that only applies if your using synthetic? It would be a good idea to get my facts straight :)
  5. Guest

    Guest Guest

    40/1 will run cooler. More oil does not equate to better cooling. I know this goes against logic, but that's the way it is sometimes.

    Run 20-24/1 for a tank during break-in if it gives you the warm fuzzies, then go to 40/1.

    Higher oil mixtures cause a leaner fuel to air mixture, not good.

    The reason the instructions say to use 20-24/1 is simply because the Chinese tend to use very low quality motor oil in the mix, not good quality (re: synthetic) oil.
  6. rcjunkie

    rcjunkie Guest

    These engines are not powerhouses and do tend to slow down a bunch on hills, especially at my altitude fo 6800 feet.

    With that said, when I experience a loss of power I immediate check fof two things:

    1. Air leak...could be in carb, could be intake gasket etc..

    2. LOOSE HEAD BOLTS <---much more common :)

    Next time you are on a hill and losing power, slowly engage carb choke and see if there is a setting that improves power. If there is a setting that helps, it means you are running too lean and overheating your engine.
  7. SlicerDicer

    SlicerDicer Guest

    I would assume that would be similar to the adding more thermal paste while mounting a cpu heatsink does not equate to cooler cpu and will actually overheat. Got it! :)

    I guess I will run 40:1 after breakin and see how it goes.
  8. Ty

    Ty Guest

    thanks for that...

    firstly i've made sure the head bolts are tight

    tried to get up a hill and adjusted the carb with no success in improving performance.

    is it normal during break in to lose power...then it will come back later? before this problem i could easily get up hills and now it struggles at slight inclines and dies on the steep

    im pretty sure im still in break in period as i've done about 40-50km and there is still knocking sounds in the engine so i wont try the 40:1 mix yet.

    any other thoughts?
  9. Ty

    Ty Guest

    oh and is a plug short for spark plug?
  10. Guest

    Guest Guest

    Yes, plug is hort for spark plug.
    What's this knocking sound you are refering to?
  11. locoWelder

    locoWelder Guest

    try replacing the plug wire itself....use a automotive type 7.5mm will work fine ....cut to fit you dont want a loop in it......just twist to get it out of the cdi

    knocking? is there anypower loss on the flats? if so you might want to check the rings
  12. gone_fishin

    gone_fishin Guest

  13. rcjunkie

    rcjunkie Guest

    Purpose of engine break is to improve engine performance. It occurs incrementally and should always be in the direction of improvement, not decremental.

    Whose engine did you buy? Its possible that you got one with inferior machining with sloppy tolerances.

    You may want to closely check the engine for sings of leakage. A bad jug gasket or (split)case gasket can dramatically decrease performance. THe entire crank/jug must be sealed for a 2 stroke to work.

    Pull your head and jug and take a peak as a minimum. Take a look at the cylinder and piston. Any glazing on cylinder or piston scuffing mean a minor rebuild is in your future.

    Also, rotate engine manually to ensure there is no unusual binding or friction.

    Is your clutch adjusted properly? A clutch that slips may be causing your problem but you would hear the engine revving up without any additional speed gains.

    Anybody else got any ideas?
  14. Ty

    Ty Guest

    guys thanks heaps for the help, here's what happened;

    after every ride ive noticed that the spark plug has been loose and ive had to tighten it all the time. turns out the vibration from the plug has stuffed the thread on the head of the engine creating a leak creating my loss of power.

    so ive replaced the head and plug and learnt that i must check my plug is tight! best of all my powers back.

    thanks again
  15. ibeenjammin

    ibeenjammin Guest

    OK my story is similar to Ty's, except my spark plug is very secure. When I was on my first gallon of gas, the bike ran great. When I put in the next gallon of fuel, about 1/2 through it, I have noticed significant power loss, mainly uphills. I have not replaced my plug wire yet. I have replaced my intake gasket becuase I noticed mine was half gone after my first notice of power loss. after replacing the gasket, It was extrememly dificult to get the bike started. When I put in my third tank of gas, My throttle wouldn't stay at an idle, I would have to continually twist the throttle in order to keep the motor going. So, I figured out that it was possible to adjust the throttle by twisting out the mixture setting above the carb cable. I moved the e-clip down a notch. After doing all that, I got it to idle on its own, but it just sounded like it wasn't working right. After replacing the intake gasket for the second time, it works fine on the flats and down hill, but up hill, I have to pedal like a mad man. I broke in the motor the way the seller told me to. But my power seems like it is fading fast.

    Things I would like to do.

    1. Remove the carb and make sure the jet is not blocked.
    2. Someone metioned the other gaskets in the body of the motor need to be air tight as well or there can be a reduction in power. my question is, are the other gaskets sealed with high temp sealant as well? if not, should I use it?

    It is very frustrating when these motors start acting wierd. I am hoping that someone has already experienced my problem and have the perfect fix for me. I am open to suggestions.


  16. gone_fishin

    gone_fishin Guest

    me & my 70:

    sealed carby/intake with shim/wrap made of beercan (R&D is fun!)
    replaced intake gasket w/fiber & permatex both sides
    original head gasket (no treatment)
    base gasket replaced with layer of permatex high-temp rtv only.
    original exhaust gasket (that's right, original) with permatex 1a both sides
  17. ibeenjammin

    ibeenjammin Guest

    is that permatex 1A High Temp sealant? I used some type of sealant that said it was for oil and fuel, not sure if it is 1A or not, I am at work and do not have access to it. I do recall that it was a a dark brown color. When I used it for the intake gasket, it was bubbling out when the engine was warmed up :shock: It seemed to work fine, but still no power. I then bought some high temp sealant, black tube and a silver/gray color sealant, :???: not sure if this is what I should be using or not, oh well, live and learn. What did you use to cut you beer can strip?

  18. JosephGarcia

    JosephGarcia Guest

    Your engine is old and cannot compete with gravity anymore? compression problems? idk
  19. ibeenjammin

    ibeenjammin Guest

    It's maybe a month old. :shock: I hope it is not too old.
  20. Guest

    Guest Guest

    When the sealer bubbled out, did you replace it, or just try to run it after that? If you did nothing, I'd use a regular piece of gasket paper and re-do the gasket, no sealer this time.