Engine too weak?

[mark20]

That's right. Cheap China Engines are messed up.

your spark plug is very black, could be the remaining oil in the bottem end thats getting mixed up causing it to run slower (aka fouling the plug)

also the engine is running rich (causing it not to rev up) you need to get a smaller (leaner) jet to compensate.

but first get a NGK B6HS spark plug and see if that fixes it

then if that doesn't work get a leaner jet kit
(stock size is .70 so try a .68 or a .66, that should get you in the right zone)

 

[inspectorcritic]

Your pic is too rich put it on the very end ringer, also it's loud and annoying but take the end cap off your muffler just undue the screw tap a few times pull it out.
That will give you the stock performance you anticipate.

 

[FurryOnTheInside]

Stock jets are about a #70 and that is too large. Buy some 5mm Dellorto pattern jets in sizes up to 69. Replace the stock air filter box with a better and bigger air filter. Then try out the different sizes of jet.

Use a quality NGK sparkplug anyway. B6HS or cooler. B7HS if the weather gets hot enough.

 

[Sumsloppymeet]

Just empty your gas tank keep you're plug out and try to put the piston as low down by turning your back wheel once its low you and your friend should one grab the front other grab the back and flip it over lightly shake it see what pours out and grab an NGK that might be easiest fix

 

[Eddie2Stroke]

Your running too rich says the spark Plug, why your lack of power and too much oil to fuel ratio causes low power, not enough explosion or fuel to combust and ignite giving power, I'd take the plug off and peddle it for a few minutes with the fuel petcock off. Just keep letting the piston splash out the oil after a few minutes it should of pushed some fuel/oil out the hole and screw the S/P and run it allow it to run dry, or shut off by itself and pumpthe carb of fresh fuel and run it again with your riding it for a few blocks, the old oil and fuel should be gone. Clean the plug with a steel wool or wire brush and gap to .32-.35 and run it should run better with increased power.

These things happen, I've ran my chinagirl to the ground and back numerous times in our 8,000 mile together, I'm currently rebuilding the bottom after I had ported and piston/bearing swapped it. currently running my 100cc kit(80cc) runs like a champ, attacks any hill, and revs pretty decent, topped it at 41mph so far with 230miles barely.

 

[gary55]

Start with replacing plug, putting the clip on the top notch of the needle in the carb. and re torquing the head. It's probably loose. If you have road it 90 km at 32;1 you probably have used up any excessive oil in the crank. A lot of heads show a small amount of oil at the plug, but if leak is bad enough it could be a problem. What is the elevation where you live?

 

[Ahmet]

Start with replacing plug, putting the clip on the top notch of the needle in the carb. and re torquing the head. It's probably loose. If you have road it 90 km at 32;1 you probably have used up any excessive oil in the crank. A lot of heads show a small amount of oil at the plug, but if leak is bad enough it could be a problem. What is the elevation where you live?

I ordered jet kit from China. I guess that will do the job. Looks like rich mix goes into the engine. Fuel consumption indicates that.

 

[RB55]

You’re running your gas/air mixture crazy rich from the color of the sparks plug. The carb of these Chinagirl engines is factory tuned to run too rich, since they are using a 16:1 mix of 10w-30 motor oil and gas which seriously leans out the fuel/air ratio. On mine, I removed the air filter completely and run no more than a 32:1 mix of gas/oil. I tried running Opti 2 at 100:1 and that mixture was way too rich, proving my point. Dropped back down to 30:1 and now works fine.

Replace the sparks plug and remove the air filter to see if that makes any difference before your jets arrive. As suggested above, as soon as you get the jets, start with the leanest jets to see if that makes any difference. Also, tighten down your head and sparks plug really well. Good luck!

 

[Ahmet]

You’re running your gas/air mixture crazy rich from the color of the sparks plug. The carb of these Chinagirl engines is factory tuned to run too rich, since they are using a 16:1 mix of 10w-30 motor oil and gas which seriously leans out the fuel/air ratio. On mine, I removed the air filter completely and run no more than a 32:1 mix of gas/oil. I tried running Opti 2 at 100:1 and that mixture was way too rich, proving my point. Dropped back down to 30:1 and now works fine.

Replace the sparks plug and remove the air filter to see if that makes any difference before your jets arrive. As suggested above, as soon as you get the jets, start with the leanest jets to see if that makes any difference. Also, tighten down your head and sparks plug really well. Good luck!

Do i tighten the head with hand? No torque wrench? Because i don't have one.

 

[RB55]

Do i tighten the head with hand? No torque wrench? Because i don't have one.

no, tightening the spark plug or the cylinder head with your hand is the easiest way to lose compression on your engine...
For the sparks plug, use the supplied hex socket and a screwdriver to tighten it down pretty tightly (do not overdo it). Your head should be tight from the factory, but if you decide it might be one of the reasons you are losing performance, then buy a properly sized hex socket and torque wrench and tighten to about 12 ft-lbs of torque. DO NOT hand tighten either the cylinder head or sparks plug; that’s the easiest way to lose compression and engine power.