China girl motor 4 cycling

[old motorbike]

My old original 80-66cc still stock with low miles still insists on 4 cycling @ part throttle and cruising. It's better warmed up. Works better at low rpms under load. I moved carb clip to top groove on needle and run 24:1 Do I need a longer needle? Smaller jet? or something else? Different carb?

 

[Bikeguy Joe]

Re: China girl 4 cycling

That's fairly normal. If it breaks in and out of a four cycle when cruising with a light load, it's about perfect for these old school two strokes and perfectly normal.
If it runs at a four cycle all the time when under light load, go to a smaller jet, or solder the one you have closed and re-drill it a little bit smaller.

 

[Bikeguy Joe]

Re: China girl 4 cycling

You can also try opening up the exhaust (cutting the baffle a little) or opening up the air filter cover to allow the ebgine to breath a little more.

 

[MB-Monkey]

Re: China girl 4 cycling

it would also be nice to see the plug chop to see the result. BGJ is right as well a good motor will cruise in and out of the "4cycle"

 

[old motorbike]

Re: China girl 4 cycling

Thanks everyone, I like the jet solder idea. Maybe being at sea level helps cause it more also. For the first mile or so it 4 cycles all the time. Also we've been having 80-90% humidity lately.

 

[Russell]

Re: China girl 4 cycling

What does the term 4 cycilng mean when talking about a two cycle engine?
I recieved my first engine(80/66cc) and I have acouple of questions. First the chain, the rollers have about 1/32 travel side to side. Is this normal, seems that every other chain I've come across the rollers have min side play. Next question, The sleeve casting has a defect. You can see one of the piston sleeve bolts or bolt sleeve due to a air buble in the casting. I do not think it is a problem, but not sure? Thanks Russell

 

[lordoflightaz]

Re: China girl 4 cycling

What does the term 4 cycilng mean when talking about a two cycle engine?

I would like to hear 4 cycling, I understand the concept, but just what does it sound like?

 

[Bikeguy Joe]

Re: China girl 4 cycling

In order of asking-

Chain rollers with side play- "normal" for these kits.
Casting error- Usually not a problem, but some sellers will replace the cylinder or kit if you let them know about it.

Now, "4 stroking" or 4 cycling sounds like a rough stacatto or firing every other cycle, as opposed to a smooth ""buzz" of the 2 cycle sound. If your engine four strokes all the time, it's too rich.

When these ancient tech piston ported two strokes are "right on" with their mixture, they will break in and out of the two cycle/four cycle sound at cruise or light load, and break into a clean two cycle "buzz" when you twist the throttle, or start up an incline.

Part of the reason is the crappy carb, and part of it is the "ancient tech piston porting". If you have one that runs in a clean two cycle at cruise, you are getting close to a very lean condition.

 

[Russell]

Re: China girl 4 cycling

Thanks for the help!

Russell

So many projects so little time. If anyone invents a 36 hr day it would be a big help to me!

 

[Echotraveler]

Re: China girl 4 cycling

if you wanna open up the muffler, i could recomend cutting 1/2" off from the staight tube that lets the smoke out off the muffler....the one you can remover on the end of the muffler...cut cut until you feel better or you damage it lol... thats why 1/2"cuts are recomended.

 

[Junster]

Re: China girl 4 cycling

24hr day is ok for me I just need 8hr rest in 4 hr sleep. Remind me to ask for that when I find that genie in the bottle.

 

[lordoflightaz]

Re: China girl 4 cycling

In order of asking-

Now, "4 stroking" or 4 cycling sounds like a rough stacatto or firing every other cycle, as opposed to a smooth ""buzz" of the 2 cycle sound. If your engine four strokes all the time, it's too rich.

When these ancient tech piston ported two strokes are "right on" with their mixture, they will break in and out of the two cycle/four cycle sound at cruise or light load, and break into a clean two cycle "buzz" when you twist the throttle, or start up an incline.

Sure but it would be great if someone who know what it sound like could like maybe record the sound for us to hear. I have enough trouble hearing as it is and it would be good to know the sound.

 

[Bikeguy Joe]

Re: China girl 4 cycling

Calling all techies....I don't know how to record it to my computer.

 

[MB-Monkey]

Re: China girl 4 cycling

BGJ if there is a "headphone jack" on your recorder attach a 1/8" to 1/8" cable from the recorder to the blue jack on the back of your pc then use sound recorder to capture it.

programs\accessories\entertainment\sound recorder

open the app and then press play on the device and click the record button. when the sounds are done click the stop button then save it to the desktop

MBM

 

[Bikeguy Joe]

Re: China girl 4 cycling

I have no recorder or mike.

 

[Bikeguy Joe]

Re: China girl 4 cycling

It really is easy to tell between the four cycle sound and the two cycle sound if you hear them.

One (two cycle sound) is very smooth, the other is rougher, sounds like it's firing every other time (because it is) and makes little power and more smoke and vibration.

When in the cruise mode and it's breaking back and forth, you will still hear it going from a two cycle to a four cycle and back, not in a regular pattern.

Sorta like Baaaaaaabbbbbubaaabubaabubaaaaaaaaabbbbubaaaaaaa.
If that makes any sense.

 

[matt167]

Re: China girl 4 cycling

most weed eaters will do the same thing.. they just begin to sound 'diffrent' and that's when there 4 cycling.

 

[marioaz]

Re: China girl 4 cycling

Bikeguy, great description. Now, my GT-4 will 2 cycle when in light load. As I increase throttle it will come out of 2 and go 4 cycle with accompanying loss of power. Back off and give slow throttle and it will again 2 cycle.

 

[chrisme]

Re: China girl 4 cycling

Since I got out of break-in and switch to 30:1 (ish) oil ratio, I have a LOT less 4-cycling.
I have some cruising when it is still cool, but once it is nice and warm I barely have any. And I'm not running lean, or rich, according to my plug. I'm running just perfect
My engine has around 300miles on it now. Probably 350 after this morning. I average almost 40 miles a day.

At that rate it will probably wear out by the end of the summer... maybe I'll go 4-stroke.

 

[Bikeguy Joe]

Re: China girl 4 cycling

Bikeguy, great description. Now, my GT-4 will 2 cycle when in light load. As I increase throttle it will come out of 2 and go 4 cycle with accompanying loss of power. Back off and give slow throttle and it will again 2 cycle.

The jet is too big, or the needle is too high (clip too low).
Or possibly (doubt it) the taper too sharp on the needle.

These carbs are fun aren't they?