Will do. I have always been taught to err on the side of rich (2 strokes are less likely to burn up if theyre rich) I currently have the pilot screw out 1.75 turns.

 

Ok dropped the E ring and it seems to run better but still having the same issue. I did think of one thing that may be giving me issues. When I got the bike the fuel cap (one with the gauge) was broken so I put a polaris one I had laying around onto it. The new cap that is on it does not have a vent. could I be starving the carb of fuel possibly? would that make idle difficult?

 

Spark plug is black and looked wet. Looks pretty rich.

Plug gap. I dont have a manual so I do not know what it is supposed to be.

 

Yes, an unvented tank could cause problems, perhaps more at higher RPM, vs. idle. Try it with the cap loose, or with a rag instead of a cap. If
that makes a diff, you may have something there.

Plug gap looks big. Spec is prob closer to .030". I like to crank the engine with plug out, but connected, to see what kind of spark you have.

Have you looked at the jets inside float bowl when carb was out?

 

When I had the carb out I took all the jets out and made sure they were clean. I did not check the sizes of them though. I think I may be too rich on the fuel screw and thats what is killing the idle? And then maybe my main jet is too small or I have the needle set wrong again. I suppose tight (or loose but they arent ticking) valves could exhibit the same behavior. I will check those once I get a chance to wash off the engine (still covered in mud) I am getting a pressure washer today and once it gets above freezing (hopefully soon) I will give it a good wash. What are the intake and exhaust clearances for this engine?

 

I have found that new Chinese carbs need full disassembly and cleaning with carb cleaner spray and air. The pilot screw setting you are using is prob not causing your problems. Same with valve clearance, unless there is none. Use .008" if you do not have a spec. The wrong or clogged low speed jet can cause these problems. Put the main jet needle in the second from lowest clip setting.

Keep trying to get that OEM carb back.

 

Ok good stuff. I moved the E clip to second from the bottom. Fuel screw is out about 1.5 turns. New plug is in. It will now run very well but only if the 'choke' is just barely on. It idles very well with the choke up about 10% but when I turn it off it dies immediately. It will ride kind of with the choke off all the way but with it at 10% it rides perfect. Now with a normal choke that would mean to me that it is lean since a normal choke is air restriction. Will it be the same with this one? More fuel screw? or move the clip up one more notch?

 

In this test, is it fully warmed up? Air cleaner mounted?

What about the idle adjust screw on the throttle? Have you adjusted that when trying to get it to idle with the cold-start OFF?

You may need a larger slow jet.

 

It was fully warmed up to operating temperature. The new air cleaner is installed and oiled. I have been using the idle screw on the throttle almost exclusively now because getting to the one on the carb is a pain in the butt. I adjusted it to almost idle so it would fire once or twice when I ran the starter and then used the adjustment up at the throttle to adjust it the rest of the way. Is this 'choke' only modifying fuel flow not air flow? Meaning that if it is only wanting to run with a tiny bit of choke that its still too lean? Could my choke be messed up? Which one is the slow jet? I have tuned many carbs including dual carbs but I honestly have never had to change jets out to get an engine to run right.

 

Welcome to the world of Chinese carbs.

The cold-start valve opens a passage inside the carb to allow more fuel to richen the mix somewhat. The fact that opening it a bit makes the engine run better indicates that you are not getting enough fuel thru the slow jet at idle. That jet is the one that is not the main jet, accessible from inside the bowl. Take it out. Even if it is clean, it may be too small. It is prob not marked with a jet size, however. Take a photo of the underside of the carb with the bowl off.

Don't adjust the mechanical idle speed at the handlebar. Use the stop on the carb, even if it is hard to access. The one on the handlebar is just to take up slack in the cable.