Engine Trouble Problem with engine not running correctly

Discussion in '2-Stroke Engines' started by scooter3, Jul 23, 2011.

  1. scooter3

    scooter3 New Member

    I have searched the forum for this but I can't get my hands wrapped around a good solution for my problem. I have worked on 2 stroke motors before and 90% of the time I can figure them out so, I am not totally ignorant as far as the motor is concerned, just this style of motor is new to me.
    Problem: I have a RAW brand motor I bought used on a bike already. I can get it to start but and idle for a short time. Once it does start it runs extremely rough, and has no power, it will not throttle up, and smokes like a train. The kicker is that I have fooled with the carb and every now and then it will run and run strong. I took the slide out to see if it was in the right direction as I have seen discussed on here. I think its in the right way ,but nobody ever says which way its goes, they just say its not in correctly. I checked the bowl to see if the jet had fallen out of it and it wasn't in the bowl. Once after it ran rough, I stopped it and took the plug out and it was wet. I am thinking it is flooding itself out somehow but I am not sure. I took the breather off it just so it would get the max amount of air and it still floods. I also took the muffler off because I thought it might be stopped up but it ran the same with it as with out it. Any suggestions????
     

  2. Al.Fisherman

    Al.Fisherman Active Member

    As far as the carburetor slide, unfortunately it can go into the carburetor wrong. If you look where the slide fits in you should see a small nipple sticking out. The grove where the cable runs the length of the slide (small long grove), the nipple has to line up in that grove. This will position the angle cutaway at the bottom of the piston to line up with the idle screw. Rough running may be contributed to improper mounting. May have a intake leak. Clean out the needle and seat. Float might need to be adjusted. I thought about the exhaust, but you eliminated that.
    http://s982.photobucket.com/albums/ae309/Ron-Becker/Engine Mounting/
     
    Last edited: Jul 23, 2011
  3. scooter3

    scooter3 New Member

    Yeah that's what I figured and that's the way I installed it. When I took it apart I deduced that it more then likely had to go that way. But, its always good to ask anyways. Thanks
     
  4. Lazieboy

    Lazieboy Member

    issues

    I had an airleak issue from an extendo card mod. and it ran like s*it fixed and runs smoother and gained 9mpg's. Take muffler off or unscrew the tip and see what happens, that was fouling out my plug.
     
  5. scooter3

    scooter3 New Member

    Well, my motor is stock even though I can tell someone else has taken it apart previously which scares me to a point. What do you mean by unscrewing the tip? That baffle looking thing thats up in the muffler?
     
  6. ddesens

    ddesens Member

    Do you have an NT carb or a CNS (red breather)?
     
  7. scooter3

    scooter3 New Member

    NT, if the NT has a black breather
     
  8. Al.Fisherman

    Al.Fisherman Active Member

    He took the muffler off and it didn't make a change.
     
  9. scooter3

    scooter3 New Member

    Yeah I'm pretty lost on the whole situation. The only thing I can figure is the carb malfunctioning and feeding too much fuel.
    The only other thing I didn't mention was it does not have a in-line fuel filter. I know it needs one obviously and I know that every time you filter something it causes restriction. Would the absence of an in-line filter cause this much trouble in the way of flooding?
     
  10. Al.Fisherman

    Al.Fisherman Active Member

    The only reason for a in-line filter is to filter the fuel before it gets to the carburetor. Yes it may look like the filter is a restriction, but if you look at the fuel line between the filter and the carburetor it should almost be full.
     
  11. scooter3

    scooter3 New Member

    Well it doesn't have a filter at the moment. At some point someone (not me) has removed the filter and replaced the stock fuel line with a solid line. I do not know what the stock fuel line size is but if it has been replaced for example with a larger diameter line I wonder if that could cause it to flood. I am sorta grasping at straws at the moment haha.
     
  12. motorpsycho

    motorpsycho Active Member

    Ok, does it still have the gas in it that was in it when you bought it?
    I think that maybe there's too much oil in the gas.
    Drain the gas out of the tank and mix up some fresh gas at a 32:1 gas-oil ratio.
    If there's too much oil in the gas it can cause the problems you are describing (low power on occasion and smoking like a frieght train).

    If the carb is flooding over, you will have to raise the float level slightly, but I wouldn't mess with it unless gas is literally coming out of the overflow tube from the carb.
    The absence of a filter would not cause too much gas to come out of the carb into the engine. The fuel flow into the engine is restricted by the needle and seat in the carb. The carb will only take as much fuel into the bowl as the float will allow. once the bowl is full, the needle & seat closes and no more fuel will flow into the bowl. As the engine is running, and gas is getting sucked out of the carb., the float will go down, which will open the needle ever so slightly to let fuel fill the bowl. As the fuel level in the bowl goes down, the float goes down. When the bowl is full, the float will go back up and close the needle.
    if too much gas is getting into the engine, it's either a jetting problem or a stuck float.
    The only real contributors to fuel getting into the engine is the main jet (you already checked it)

    Unless the person who owned it before you drilled out the jet or put in a bigger jet.
    If he drilled out the jet or put in a bigger jet, it could be too rich allowing too much gas and not enough air.
    Did you look at the main jet and see if there's a number on it or to see if the hole looked like it had been drilled out?
    If the jet has a number on it, chances are it's not the original jet. The original jets in these carbs do not have numbers stamped into them, but most aftermarket ones do.
    If the jet looks like it has been drilled out, it's quite possible that he drilled it too big.
    At that point you will need to get a stock jet and see how it runs with it in there.
    If it's too lean or too rich with a stock jet, then you may have to get some aftermarket jets. Or you could solder the hole closed on the stock jet and re-drill it depending on if it needs to be richer or leaner....it can take a lot of time and it's all trial and error.
    I think I have a stock nt jet here somewhere, and if you think you might need it, let me know. Maybe we can work something out depending on where you live.
    If you need it i'll give it to you for free.
     
    Last edited: Jul 24, 2011
  13. motorpsycho

    motorpsycho Active Member

    no, the size of the fuel line will not cause the carb to flood.
    it's the float setting that will cause a carb to flood over.
    once the bowl is full, the needle & seat will be closed and no more fuel will flow into the carb no matter how big the fuel line is.
     
  14. scooter3

    scooter3 New Member

    I drained the gas out of it after I got it home. I put the gas I use in my other 2 cycle engines which is 50:1 so too much oil isn't the problem. I know its too lean but that shouldn't cause it to flood.

    I have no idea if the jet is stock or not. Ill have to check on it tomorrow.
     
  15. scooter3

    scooter3 New Member

    Alright I checked it, its the stock jet. I have gotten it to run better but it smokes bad and doesn't have any power.
     
  16. motorpsycho

    motorpsycho Active Member

    do you have any idea how many miles are on the engine or how old it is?
    there's a good chance that the rings are worn out and it may have low compression.
    you shoudl do a compression check on it, but i have no idea what a good # for compression on these engines really is.
     
  17. scooter3

    scooter3 New Member

    I don't know but according to RAW's website they have been selling these motors since 06. Every now and then when its not flooding itself it will run right. I'm thinking of just getting a new carb since this one has been fooled with.
     
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