ok I'll post a pic then ask some questions about the carb on my 50cc 2 stroke mini's.


<img>http://im1.shutterfly.com/procserv/4...sc</img>

A is the idle screw, B is the mixture screw, but I can't figure out what C is. Problem is I had problems with the carb, took it apart cleaned it up and bike ran fine at idle. Absolutely nothing after idle. I blocked off the port marked C which sounds like some kind of atmospheric exhaust or cylinder pressure I don't know, but anyhow it runs fine with it blocked one bike but not the other. That's the first question. Next is on the mixture screw if 3 O'clock is all the way closed I can't open it up beyond 2:30 maybe 2 O'clock without it stalling out this is like 1/16 of a turn. If this is happening because of too much air in the mixture should I be running a bigger main jet? If it can handle a bigger main jet will this added fuel mean added performance? Both bikes are running fine now, just can't figure out why the port needs blocked on one and not the other, plus the mixture screw thing has always baffled me, when I first got them it took me awhile to figure it out because everybody says start at 1/4 turn which kills these lil bikes.

Thanks


sorry I don't know how to post pics I tried a photo gallery.

 

Not alot of carb experts here I'm guessing!! From what I can figure it's a vent port for the float bowl, but then I'm even more confused as to why it runs better with it blocked. I'll keep tinkering, I was just hoping some people here were more carb friendly.

 

i would write down what the stock settings were and go out and buy 3 or 4 main jet sizes larger and see what works best. if your idle is fine then your pilot jet should be ok ( i think your pilot only comes into play from idle to 1/4 throttle after that it's all mainjet) granted your needle jet and clip position might be a factor but i wouldnt fiddle with that just yet...note if your engine stumbles at full throtle you might be too rich on the main jet. i hope this helps you some.

 

There is alot with jetting, temp is one factor, air cleaner is another etc. If the pics were better I could most likely help you.

 

Well I got the clip all the way down on the needle to richen it up and it still lags when you take off, slowly building momentum. If you pull the choke up it takes right off, so it has to be lean. I found a hole in the J tube for the air cleaner, so that might be why I am running so lean. I'm going to come up with a straight tube for the air cleaners anyway.

I'm still confused on the whole pilot thing. Like you said it idles pefect, but start cracking the throttle and it doesn't want to go until the choke is pulled. I really don't know if this falls into the idle-1/4 throttle pilot category or not.

 

what kind of pics do you need?