Little fixes, need advice??

Discussion in '2-Stroke Engines' started by scubaru89, Sep 19, 2012.

  1. scubaru89

    scubaru89 Member

    So I got my engine installed after 4 hours, played around with it for awhile and got it up and running. I've been on it for maybe 15 miles today to let things seat into place, see what the issues are gonna be etc. Honestly I don't have as many issues as I thought I would, just want some help on the few of them.

    1 - The fuel shut off is leaking from where it connects to the gas tank.
    Possible Fix: I am thinking just get some sealant made for use with gas applications?

    2 - Gas Cap Broke, wont lock into tank top
    Possible Fix: Find a replacement?

    3 - Spark Plug boot broke
    Possible Fix: Replace the boot, where can I get one?

    4 - Carb keeps falling off intake line
    Link: Sep 18, 11 49 20 PM_zps780be1f8. jpg
    Possible Fix: Either form some sort of seal to enlarge the pipe that its fitting onto?

    5 - Idle changes, low idle when sitting, high idle when putting clutch in neutral after riding
    Possible Fix: Thinking this might have to do with the adjustment pin for ride mixture?

    6 - Gas Tank doesn't fit onto bike correctly, studs not long enough
    Possible Fix: Probably fab some simple holding solution

    7 - Now I have the basic NT carb and I know on the mixture pin there are 5 possible settings it can be set at, can anyone tell me which direction (up or down) adjust the carb in what way?

    8 - How does my idle sound?

    If you can help with any of them above please do, just clarify which number problem you are helping with. All advice welcome and appreciated!
    Last edited by a moderator: Dec 15, 2015

  2. motorpsycho

    motorpsycho Active Member

    1. remove the fuel shut off from the gas tank. get some teflon tape and wrap it around the threads of the fuel shut off, and screw it back in.

    2. get a new gas cap

    3. look at your cdi box where the spark plug wire goes into it. if you don't see any thing that looks like epoxy holding the plug wire into the box, then twist the wire counter clock wise (unscrew it). you'll see a screw in the cdi box that the wire was screwed on to.
    now, get yourself an automotive spark plug wire with a rubber boot and just screw the new wire back onto the screw in the cdi box. make sure that you get the center core of the new wire onto the point of the screw when you start screwing it on.
    you will also have to screw the tip back on to the spark plug or an automotive boot will not snap on and stay connected. (remember you had to remove that tip from the spark plug for the kit supplied boot to stay connected.)

    4. carb keeps falling off. either you don't have it tight enough, you got one with a bad clamp or your intake tube is too small in diamater for some reason.
    there is no real solution for this as far as sealants go because any kind of silicone based sealant that you try to use will not last.
    I'm sure that there are sealants out there that will work, but honestly, they will cost you more than just buying a new carb (or intake tube).
    the carb should slide onto the tube easily and then when you tighten the clamp, it should be able to hold it on tight enough so that it won't fall off. you shouldn't even be able to twist the carb with your hands once the clamp is tight.

    5. Idle changes. this could be related to the poor fit of the carb to the intake tube. It can be causing an air leak, which will make your engine lean out (idle will go up). this isn't good because if you run it too lean for too long, it will eventually burn up the piston. it will also make it hard (and no fun) to ride it. you shoudl have a nice slow idle when the bike is stilling still, and it should quickly drop back to that same idle speed when you pull in the clutch.
    i'm pretty sure you are fighting an air leak, especially since you said that the carb keeps falling off.

    6. yep, make the studs longer with some parts from the hardware store. this is simple.

    7. every carb setting is different for every engine. no 2 will run the same. It's a matter of trial and error.
    I will also tell you that the needle setting in the carb will have no effect on wide open throttle performace. moving the needle setting only has an effect fro idle to about 3/4 throttle. after 3/4 throttle the needle is out of the main jet well and is no longer metering any of the fuel. At wide open throttle, the main jet is doing the fuel metering.
    If you have an engine that bogs down (too lean - too much air) or 4 strokes (too rich - too much fuel) at wide open throttle, the only way to cure it is to do a main jet change to a smaller or bigger jet.
    you just have to play with it and try each setting. the weather where you live will have a lot to do with what setting works best for your cab and engine too.
    I still think that you are fighting an air leak at the carb to intake mounting point because of what you said about the idle going up & down.
    get the air leak fixed fiorst and then play with the needle settings.
    the way to tune a carb is to do one thing at a time and take notes on what you did and what made it run better or worse.

    your idle sounds fine, maybe a little high (but that's just my opion)
  3. scubaru89

    scubaru89 Member

    1 - Wasn't sure if Teflon would hold up or not, knowing it will, I'll be doing that tonight.

    2 - is sending out out today free of charge! :)

    3 - Last time I looked at my CDI its completely sealed on the top, including the wires (Black rubber coating). So I think I can get a boot repair kit and just replace the boot. I work at Advance Auto and I work in a few hours so I'll be sure to pick up a simple boot for it.

    4 - I am not sure if you saw the picture but its a custom built intake. Due to the size of my frame this was the only way to make it fit. I will go through everything again and make sure its all tightened down. I just replaced the copper tube last night after I made this thread to a 90* fitting and it seems to be running better and holding onto that coupling better. I've only been playing with the idle adjustment so far. Nothing else. I have noticed I can bring the bike to a nice slow rumble but the engine would stall out after a minute. I'll trace everything and tighten it all back down.

    5 - I did notice that when I'm accelerating I need to let off the throttle and then go at it again. Something when I do that helps to increase my speed and the bikes running. Not sure if thats not enough gas getting into the mixture or what.

    7 - I guess I need to play with the settings this weekend and see what I can make of it.

    Thanks for the post, a lot was pretty simple I just wanted a second opinion before I go trying things that are gonna fail or cost me more in the end.