a few 4-stroke basic questions

1. Checking the oil: The engine should be sitting level. Remember that the dip stick is just that, a dip stick. Unscrew it, wipe it clean, stick it back into the hole until it rests squarely on the hole rim, pull it out and read the level. Too many folks think that you need to wipe it clean, screw it all the way down tight then unscrew it again to read the level properly. Doing it that way will always have the full mark down in too far and thus the oil level set too low.

4 strokes, like 2 strokes, need to be warmed up before they run and idle properly.
4 strokes seem to be more sensitive to this in regards to idling.
If the engine will not idle when it is warmed up to operating temperature then yes, the idle speed needs some adjustment and most likely the idle mixture needs adjustment too.

Oh yeah, 2 strokes should idle as well and not cut out like you have experienced.

<removed out of protest to certain "staff" practices in this forum.>

Idle speed is set at whatever rpm you want for idle. Every engine is different.
I set mixture by turning till it slows one direction, then the same in the other direction, noting where the screw is, and set it in the middle of the two positions. This is usually the best setting.

In this video, Terry Blow shows the carburetor screw locations. If you are feeling impatient, fast forward to the 10 minute mark.
http://www.youtube.com/watch?v=eZP3xZVgl-I

If I may expand on what maniac57 said,

The slow speed mixture screw on the HuaSheng is a fuel adjusting screw. Turning the screw in (twisting it clockwise) closes off the passage that the fuel flows through. This will reduce the fuel flow and lean the fuel/ air ratio.
Turning the screw out (twisting it counterclockwise) opens up the passage that the fuel flows through. This will add more fuel flow and enrichen the fuel/ air ratio.

This screw has very fine threads on it to allow precise tuning of the air/ fuel ratio.
This screw should never, EVER be turned in and tightened because doing so will ruin the delicate fuel passage inside the carburetor. There is nothing to be afraid of while adjusting this screw if when turning the screw in, you are gentle and stop turning it if you feel it hit bottom ( stop turning easily).

1. Turn the idle mixture screw in until it bottoms.
2. Turn the idle mixture screw out 1 and 1/2 full turns.
This gives you a good starting point to begin the tuning process. The engine will run, poorly, but still run.
3. Start the engine and adjust the idle speed screw in to raise the idle speed or out to lower the idle speed until the engine is running at a fast idle.
4. Turn the idle mixture screw out until the idle speed begins to slow.
5. Take a mental note of the idle mixture screw's screwdriver slot position. This slot is the only indicator (pointer) the screw has to visually measure how much you are turning it.
6. While counting how many turns you twist it, turn the idle mixture screw in until the engine run faster and then begins to run slower again. Stop turning it before the engine totally dies from a lack of fuel.
The number of turns in you made now needs to be divided in half.
For the sake of discussion let's just assume that you turned it in 4 and 1/2 turns.
Half of that would be 2 and 1/8 turns.
Remember, your actual number of turns will most likely be different than the above example so do your own math from the turn count you have.

7. Turn the idle mixture screw out that number of turns that your math came up with.
Add 1/8 turn more to the turn count to give a teeny bit more fuel into the engine. It is better to be a teeny bit rich than too lean.
8. Now adjust the idle speed screw in or out until the engine idles at a good speed. Not so fast that the clutch is trying to grab, not so slow that the engine is struggling to keep running.

As the engine puts on miles and breaks in both the idle mixture and idle speed will need to be fine tuned again as the engine's needs will change as it matures. Eventually the engine will be settled in and the slow speed tuning will be good for a very long time.

You can buy a vacuum pump oil extractor from Northern Tools for under $15. To put oil back in I use a 100 cc oil syringe. That way I'm putting in the exact amount of oil the owners manual recommends.

jasemcjasen said:

im not sure why but i cannot seem to find the idle mixture screw, the location of the screw on my engine isnt a screw at all and just a flat brass-colored piece with no threads on top of it. there is a screw missing from the top but i dont think that is the right location....

Click to expand...

Can you post a picture?
On newer carburetors the screw may be covered by a thin metal cap.
Your case would be the first one I have heard of regarding the HuaSheng 4 stroke engines, however this metal cap is quite commonly found on the 2 stroke carburetors.
The cap is installed over the screw in an effort to prevent the end user from fine tuning the carburetor for the best performance and fuel economy.
The factories have to do this in order to meet EPA and other environatzi regulations. The environatzis think that once a carburetor leaves the factory the state of tune that the factory made it to will be perfect for all engines, altitudes and riding conditions and produce the least amount of exhaust emissions.
This could not be any further from real world operating truth, but the law makers know nothing about the engines and carburetors that they make the laws for.

I have the same cap on mine... anxiously awaiting help to remove it... mine runs a bit rich......

I went out and looked at my carburetor to compare it against your picture. The carburetor bodies are definitely different in regards to whole area around where your carburetor's plug and my carburetor's screw are located.
The typical screw plug is a thin aluminum disc driven in flush with the surface of the carburetor body. If it is brass it usually is a pin of a specific length or sometimes they drill a super tiny metering port in the fuel passage and plug the hole with a brass dowel. I have seen both. You could take a gamble that it is in fact a plug. To remove a plug you drill a small hole in it dead center, being super careful to not hit the screw behind it.
Twist a small sheet metal screw into the hole you drilled to grab the plug and then with pliers pull the screw with plug attached out.
If during the drilling procedure you drill in deeper than 1/16" (that is the thickness of a typical plug) without passing through the plug then it is not a plug, it is a brass dowel or fixed metering pin.
Now you have me wanting to experiment on your carburetor to determine exactly what they have done, but I do not have another carburetor to offer you.

Just confirming that there is a fuel screw behind the plug.

jasemcjasen said:

here is the carb,is there a safe way to remove this cap?

Click to expand...

I just use a nonferrous brass magnet to remove it......works great


Just kidding, do as the GearNut has recommended.

If the engine is stalling, then check and make sure the CC bushing is not dry. From what I have heard, a dry or damaged bushing can lead to many big problems.

I know this is an old thread but for others that run into it I wanted to post what I would recommend.

For one thing mine does not have a exposed fuel mixture screw either. The build date of the engine was Nov. 2013 and it also died at the factory set idle speed.

I don't agree with first going to the fuel mixture screw to keep it from dying when idling. If your idle is low to the point it's dies why not just use the screw that adjusts the idle speed (the black screw on top of carb)?

From what I have found these engines are suppose to idle at appox. 2,500 rpm if you have a tach/hour meter you can check to see what rpm yours is idling at and adjust it.

Reference link:
http://www.bicycle-engines.com/images/honda-cc.pdf

By having the ability to adjust the idle air/fuel ratio, you have more control over the idle speed, ease of starting and the ability to increase the engine's performance/ power output at lower engine speeds. Often times it also allows one to increase the fuel economy as well as the idle fuel circuit feeds fuel into the carburetor at all engine speeds, not just at idle.