Engine Trouble Can't get engine to stay at idle!!

I recently built a two stroke, 100cc motorized bike. I start to pedal with the cluch in, I release the clutch, but it wont stay at idle. I have no idea what to do. My original ratio was 40:1, then I added more oil into the tank (not a lot) for the break in period. No help. Then I udjusted the c clip in the carb for the richer setting, still no help. Any ideas of how to fix the issue?
Check for vacuum leaks.

That includes your crank seals if you have any oil coming out around your clutch case cover you very well could have a crank seal that's leaking. Which is causing a vacuum leak and other issues. My last motor I lost I believe was because of that problem and I too couldn't get the idle set correctly on that one.

Otherwise check your intake manifold and make sure that it's sealed there we're connects to the cylinder. Also make sure your carburetor is pushed on all the way on the intake manifold and that the bracket is tightened down well. Basically eliminate vacuum leaks as one of the possible issues as your issue does sound like a vacuum leak. Sometimes trying to get the idle set and it won't set is usually an indication of a vacuum leak.
 
It should fit. It's the same plug we all use
Yeah nothing wrong with that plug unless you got a high compression head and even then shouldn't be a problem. It's actually the best plug for this motor. And I definitely noticed a major difference when I ditched that Chinese plug and put that one in it. There's no way it doesn't fit you got to be cross threading it or something. Careful of doing that you don't want to ruin your head and have to rethread if you would even be lucky enough to pull that off if it happened. That plug fits. If it didn't fit you either got the wrong plug or for some weird reason the wrong plug was in the correct Packaging. That is the right plug ngk-br6hs. And as GW said we all use it. There's one other one for slightly higher performance motors if they're all tuned out and stuff and it's still pretty much the same plug. It's got to fit my friend. You do know how to put a spark plug in right? I know it sounds like a dumb question but you never know. Just turn it in by fingers and give it a snug up with the wrench you don't need to torque them right down. it's an aluminum head. Gap to 0.025" -0.028" no more than 0.030". You will notice that for the Chinese plug the three quarter inch wrench works fine you will have to ditch that wrench and use a 13/16" for the NGK. There's probably a millimeter equivalent but I can't think of what it would be right now maybe 19 mm either way 13/16".
 
How is the spark plug the problem, it also didnt work when the cclip was in the middle or at the top or at the bottom
Because those z series Chinese spark plugs are garbage and they will fail whether it be internally from the vibrations or just because they can't handle any mild fouling. Not to mention their gapped horribly. Like we're talking like 0.40" mine was anyway and it failed quick. That's why. Why waste any more time on anything else before trying that first. It's a modification / upgrade you're going to want to do anyway, trust us
 
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