Engine Trouble very hard start,... feels like TO MUCH compression,...?

Discussion in '2-Stroke Engines' started by heyscuba, May 17, 2012.

  1. heyscuba

    heyscuba New Member

    Hi all,....
    my bike suddenly is VERY hard to start,... :ack2:
    I mean it starts right up once it pops, but I can peddle the heck out of it and even be going down hill a bit and pop the cluthch and normally right where it's been starting for the last year and a half it will just do nothing and grind me to a hault,.... eventually after about 4 tries i get it going and it runs great,....
    but that first start and even after it's a little warm it is tough,.... :icon_cry:
    feels like TO MUCH compression,...?
    any idea's,...?

    scuba
     

  2. Al.Fisherman

    Al.Fisherman Active Member

    Try adding a head gasket. That will be the easiest to start out with.
     
  3. Fabian

    Fabian Well-Known Member

    Don't worry too much about the high comp. Within 600 miles, you will be wishing for some of that lost compression, as it evaporates on a daily basis.
    If you have some basic tools (drill press and taps) an option is to install a chainsaw decompression device.
     
  4. TOTAL CARNAGE

    TOTAL CARNAGE Member

    But why all of a sudden? On a year and a half old engine.
    I can't think of anything that would increase compression. ( Except being flooded )
    Maybe the compression is the same, it's just not starting right.......
    I start with the simple stuff first. Check the plug. How old is it?
    Try to start it with the plug out, laying on the head and check for a nice spark. If that all looks good move on to fuel.......Filter? dirty carb?
    Most of my hard start problems have been spark related so I would start there. Let us know what you find!
     
  5. heyscuba

    heyscuba New Member

    Al,... Adding a head gasket,...?
    you mean change out the stock head gasket,..? isn't it metal,..? are you suggesting going to a different type of gasket,..?
    I'm not sure what you mean,..?
    scuba:(
     
  6. not good news

    I'd bet that your crank bearings/bushings are getting tight. Its on the slow way to failure. Try to pull the plug, disconnect the chain and see how easy the motor is to rotate with a socket wrench. I Have seen many motors that tighten before they blow. It is not compression you are feeling , its a tight connecting rod. Don't fret it could be quite a while before it lets go..
     
  7. TOTAL CARNAGE

    TOTAL CARNAGE Member

    double trouble......would running a fuel mix with extra oil help lengthen the life of an engine like that or is it not worth it??
     
  8. heyscuba

    heyscuba New Member

    great question,... I asked my brother the same thing today,.... I am running 50 to 1, synthetic,...:ack2:
     
  9. extra oil

    That will not help , but running semi synthetic tc oil may lessen deposits and help.
     
  10. full synthetic

    This does depend on what brand you are running . Make sure the oil is jasco-tc or api-tc which is a semi-synthetic.
    Do not run tcw-3 marine oils. They are meant for low speed operation and have properties that our little motors do not like. Too little ash, burns off at low flash point,and too much dispersant.
    I doubt you are running full synthetic unless you use amsoil full synthetic. it is rated jasco-td. There are several other brands with this designation. They are great oils , but I think they are lacking some properties that these engines were designed for. These are dirty little motors that like real petroleum lubrication. Do you think that the Chinese who invented these motors have access to the selection of oils we do?
    There is a reason that we can get 3000 miles out of one of these motors and lubrication is the main one.
    I personally run a good chain saw oil that is rated tc. 40 or 50 to 1. Depends on your preferences.
    Stihl, echo and husquvarna all make a great tc oil. Readily available at your local home center.
    Almost all of it is made by citco anyway.
    At one time yamalube, quicksilver and evinrude were too.
    That should solve the mystery.
     
  11. heyscuba

    heyscuba New Member

    I am using MasterPro
    with fuel stabilizer,
    (part #80017)
    made for weed whackers, chain saw and blowers by the pic on the front of the bottle,...
    I can't tell anything else from this bottle,...
     
  12. Fabian

    Fabian Well-Known Member

    double-trouble is right. At 40:1 or 50:1 you need to run a quality oil designed for an air cooled engine, but if running 20:1, use any kind of oil you want.
     
  13. motorpsycho

    motorpsycho Active Member

    it sounds to me like possibly, it's getting hydro-locked.
    POSSIBLY, the carb is slowly allowing gas to leak into the engine while the bike sits.
    when you go to start it, this excess fuel is slightly hydrolocking the piston, which will make it VERY hard to start.
    I don't think that bearings can become "tight" unless they have not gotten any oil in a long time.
    usually. bearing will get loose from wear, but they could bind up from lack of oil.
    this is just a possibility.

    Pull the spark plug out and try to start it as you normally would. this will release the compression and tell you if it's a compression issue or a possible bearing issue.
    if it spins over easy with the plug removed, then you have something going on compression or possibly spark related.
    It is possible that a large amount of carbon is built up on top pf the piston, which would raise the compression.
    BUT, it would take quite a bit of carbon for it to raise the compression to the point to where it's hard to start.
    i'd pull the head off and look at the top of the piston.
    if there's a thick build up of carbon on the top of the piston, you can remove it with a little wire wheel in a dremel tool.
     
    Last edited: May 18, 2012
  14. motorpsycho

    motorpsycho Active Member

    the chinese didn't invent these motors, the russians did.
     
  15. Al.Fisherman

    Al.Fisherman Active Member

    Sometimes, like I had to do was to add another head gasket to the one already there. (running 2 head gaskets) to decrease the compression.
     
  16. wbuttry

    wbuttry Member

    my motor calls for 5.5 ounces i use 6 for safety and suba and it colud be just like the rest of us it is just getting old and and needs to be replaced if you got a year and a half you are doing good most only last a couple months i got a 49cc 3 yrs old and runs real good but thats cause it isnt on a bike rite now
     
  17. i stand corrected

    The Russians invented them in the 1940's and as usual the Chinese cloned them in the 1960's. The motors we buy have little resemblance to the Russian design.
    As far as a tight motor. I have seen many motors , from v-8's to weed wackers that tighten up from bad bearings. Yours could be a compression issue , but don't be surprised if the little fellah locks up.
     
  18. Masterpro= Pureguard

    Pureguard is generic petro oil. Omni specialty packaging from Shreveport La. They use Lubrizol additives. Not synthetic from the MSDS that I could find.
    It took a lot of research to find it.
    Not horrible , but there are lots better choices.
    Switch to a TC oil.

    https://docs.google.com/viewer?a=v&...90BOGM&sig=AHIEtbQ3h1xlg769Fj0UJujTDgKdtWT9_A
     
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