Still not running.

Discussion in 'General Questions' started by Ibstrange1, Apr 3, 2012.

  1. Ibstrange1

    Ibstrange1 New Member

    I have a 66cc skyhawk motor, and I recently changed the carburetor to the new er NT carb. I was not getting any spark, so I used my multimeter to check the CDI ignition module, and the settings were not consistent with the values that I saw listed elsewhere on this site. I replaced the CDI, and I still cannot get the bike to run. I check and there is gas getting to the engine, so the carb is doing something, and all of the wiring from the CDI is setup as per manual recommendations. The kill switch is functioning fine, with OL when it is in its default position, and 0 ohms when it is pressed, so I know that it isn't due to the switch. The bike sounds like it wants to run, but it never catches. Any suggestions?

  2. Tyler6357

    Tyler6357 Member

    Sounds like it's not getting fuel to me. Is the fuel filter on backwards? Is the fuel valve open? Gas in the tank? carb on upside down? Is the throttle opening correctly? Stupid questions, I know, but it sounds like the carb isn't on right or something. Maybe the float is stuck, try lightly tapping it from the outside.
  3. Ibstrange1

    Ibstrange1 New Member

    It has gas in the tank, and when I unscrew the little screw at the bottom of the carb, gas pours out, so that tells me that both valves are open. It is right side up in that it matches all of the pictures I have seen of these things installed on bikes. I will take it apart and see if I can find anything stuck. Throttle moves like normal, so I don't think that I messed it up when I installed it.
  4. motorpsycho

    motorpsycho Active Member

    so do you have spark now that you replaced the cdi?
    is the spark plug wet?
    is the choke open or closed when you try to start it?
    take the float bowl off and make sure that the main jet didn't fall out (you'll see it in the bottom of the float bowl if it fell out.)
    how are your wiring connections doen? did you solder them or use the kit supplied push together connectors?
    do you have anything hooked to the white wire?
  5. Ibstrange1

    Ibstrange1 New Member

    The connectors are the stock bad ones that it came with, but I crimped them in place, and haven't had any difficulties there. I checked the spark plug, and the thing was dry. I then took the carb off, and as I did so, fuel started pouring out the air filter. I took the filter off, and noticed that the choke was on about 3/4. I took it all the way off, and then removed the float bowl to look for the jet. The jet was right where it was supposed to be, so I put it back together, and took it for another test run. It tried, and then started right up! It seems to be idling faster than it used to, and it seemed to be bogging down a few times, but it went all the way around the block! Thank you for your help, and next time I will try to remember to check to see if the spark plug is wet.
  6. Sgt. Howard

    Sgt. Howard Member

    Have you re-soldered the ground wire of your magneto coil? This is a common issue with the China Tramp motors- pull off your magneto cover (left front of engine) and look at the wire on the top of the coil- it is cold soldered to the frame of the magneto. This connection come apart real easily without being visibly disrupted. Shave off some insulation from the black ground wire coming into the motor, right where it passes the coil ground wire connection- now re-solder the two wires together. I do this routinely before I do an instal lof a motor. 15 minute job, instant satisfaction
    the Old Sgt. :army:
  7. Ibstrange1

    Ibstrange1 New Member

    I will do that. I was going to get out the soldering iron so that I could make a better connection on the regular wiring, it wont take but a few more minutes to do that when the iron is already hot!

    I have also switched to an NGK spark plug, made friends with a bottle of locktite, and played with a torque wrench. Is there any maintenance that you would recommend to help prolong the life of my little tramp motor?
  8. motorpsycho

    motorpsycho Active Member

    yes, when you turn the carb over gas should spill out of it because it's coming from the float bowl, directly through the main jet.
    the bogging may possibly be fixed by moving the c-clip on the needle down one notch (this will raise the needle, richening the air-fuel mixture.)
    usually a bog is due to it being too lean, but if this bog happens at wide open throttle, the only real cure for that is to re-jet the carb. the setting of the c-clip on the needle only helps from idle until about 3/4 throttle. once you hit full throttle, the needle is out of the main jet hole allowing the max amount af fuel through that the jet can supply.
    if you are unfamiliar with the c-clip, it's on the top of the needle that's in the center of the carb slide (where your throttle cable hooks up inside the carb).

    if it's idling higher, that's because now it;s getting more air with the choke fully open...just turn your idle adjustment screw out until the idle is where you want it.
    before you mess with the c-clip (if you are going to) ride it for a bit and see if the bog goes away. the crank case could have a bunch of excess fuel in it.
    also, make sure that you don't have an air leak at the intake tube - engine gaslet, or where the carb seals to the intake tube.
    with the engine running, spray a TINY bit of starting fluid around the intake - engine gasket and arounf the carb-intake seal. (spray one area, wait, and then spray the other area). if the engine revs up after you spray either of these areas, you have an air leak at the area that you sprayed. an air leak will also cause a high idle and a bog.
  9. Ibstrange1

    Ibstrange1 New Member

    That is really helpful! The bog is around 1/4 throttle, and it is inconsistent. That seems like it would be more likely to be caused by an air leak than a needle position. Is there something I can put on there to help seal it up versus just pushing on on there as tight as possible and then tightening it? I was thinking of something along the lines of the "rescue" tape you see, which is a silicone tape that sticks to itself, or some kind of RTV sealant from the parts store?
  10. motorpsycho

    motorpsycho Active Member

    actually no...silicone will not hold up when exposed to gasoline. it may last for awhile, but it will probably fail over time.

    the best thing to do is to get an o-ring and drop it inside of the carb throat where the intake tube seals against the carb. the o-ring should be made of Fuel resistant Viton, not rubber. rubber will swell and break down when exposed to gas over time and it could end up getting sucked into the engine. an o-ring in the crank case, probably wouldn't be very good.
    sbp sells these o-rings, or if you know the size, you can try to get one at an auto partrs store.

    as for the intake tube leaking where it bolts to the engine, the only cure for that is a new gasket. you can either buy a new gasket that's already made, or you can buy a sheet of rubber ghasket material from the hardware store and make your own for pennies.
    sbp doesn't have the intake gasket, but if you search around, one of the vendors here probably sells them. you can even find them on e-bay sometimes, but those gasketys can be made of a cardboard type material, which is the same as the stock one, and it too will fail eventually.