Idle screw setting and WOT bogging issue
I have a china "Raw 80cc" engine that I need to have the idle screw pretty much screwed in all the way to have the engine idle without dying out. I find this abnormal because my other "raw 80cc" engine idles fine with the screw roughly half way in or so.
I am not sure what exactly is the problem, but I am going to throw out some ideas I have in mind and hopefully someone can help me:
I been having issues where the engine bogs (hesitates) slightly at WOT (~30 mph), but continues to pull and goes even faster if I back the throttle off slightly (up to ~34 mph). Because of this, I know I am not maxing my CDI or engine. Just to clarify, in my case, the bogging is more of a hesitation than full on loss of power.
1) Fuel frothing: Rejected this idea, because if it was indeed fuel frothing in the carb bowl, I shouldn't be able to go even faster (more vibration) when I back the throttle off slightly. All mounting bolts are tightened well.
2) Fuel starvation: I read in another post that this is indicative of fuel starvation. I pulled my plug a few times and noticed it's a nice golden brown, so the fuel/air ratio should be correct. I even bought a new carb and tried it out, but still have the slight bogging at WOT. But I have yet to try another jet. This is where I am unsure do I need to go with a larger jet (0.72) or smaller (0.68). I believe the stock NT carb jet is 0.70. So far, this idea seems to make the most sense in my case. Will a new jet mess with my air/fuel raito, requiring me to tinker with the c-clip?
3) Possible air leak: I tried spraying carb cleaner around gaskets of intake, carb, etc during idle to see if the idle changes. The engine didn't change in idle when I sprayed carb cleaner, meaning there are no air leaks.
4) Exhaust flow restriction: rejected this idea because I can go faster when I back the throttle off slightly.
So these are my hypotheses and my reasoning behind each. Perhaps, the fact that I have to screw in my idle adjuster pretty much all the way in is somehow related to the problem (not necessarily the cause) I am having with the bogging at WOT.
I have a china "Raw 80cc" engine that I need to have the idle screw pretty much screwed in all the way to have the engine idle without dying out. I find this abnormal because my other "raw 80cc" engine idles fine with the screw roughly half way in or so.
I am not sure what exactly is the problem, but I am going to throw out some ideas I have in mind and hopefully someone can help me:
I been having issues where the engine bogs (hesitates) slightly at WOT (~30 mph), but continues to pull and goes even faster if I back the throttle off slightly (up to ~34 mph). Because of this, I know I am not maxing my CDI or engine. Just to clarify, in my case, the bogging is more of a hesitation than full on loss of power.
1) Fuel frothing: Rejected this idea, because if it was indeed fuel frothing in the carb bowl, I shouldn't be able to go even faster (more vibration) when I back the throttle off slightly. All mounting bolts are tightened well.
2) Fuel starvation: I read in another post that this is indicative of fuel starvation. I pulled my plug a few times and noticed it's a nice golden brown, so the fuel/air ratio should be correct. I even bought a new carb and tried it out, but still have the slight bogging at WOT. But I have yet to try another jet. This is where I am unsure do I need to go with a larger jet (0.72) or smaller (0.68). I believe the stock NT carb jet is 0.70. So far, this idea seems to make the most sense in my case. Will a new jet mess with my air/fuel raito, requiring me to tinker with the c-clip?
3) Possible air leak: I tried spraying carb cleaner around gaskets of intake, carb, etc during idle to see if the idle changes. The engine didn't change in idle when I sprayed carb cleaner, meaning there are no air leaks.
4) Exhaust flow restriction: rejected this idea because I can go faster when I back the throttle off slightly.
So these are my hypotheses and my reasoning behind each. Perhaps, the fact that I have to screw in my idle adjuster pretty much all the way in is somehow related to the problem (not necessarily the cause) I am having with the bogging at WOT.
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