Carb settings

[baroquenride]

I have a 125SM with about 3000km that has difficulty starting when cold or even warmed up on occasion and the choke doesn't work. I took the carb out and looked at the jets: 110 main in good shape, but I'm not sure about the air bleed jet? (the one with the multiple holes) Should I be able to see all the way through that? Currently I can't. Also, it doesn't seem to have a number size when I looked. Also, I could not unscrew the jet in the side of the carb body to pull it out and look at it. I suppose I could shoot air in that line to see if it comes out the other end. It appears that the idle set screw should be at 2 turns out according to a couple threads I read? Mine was set at 1.5 turns out and seemed to idle ok after it gets started. Finally, what is the best setting for the E-clip on the needle? Mine was in the middle, but I'd always had a slight hesitation mid-throttle and wondering if lowering it one notch to raise the needle would be better?

[baroquenride]

I came back to it this evening and looked again at the pilot jet. Turns out it does have a hole going through the center as seen with my headlamp and wood background with my readers on, and looked perfectly fine. Also I blew through the side jet in the bowl to make sure it was open and it was. I put it all back together and placed the C-clip on the 2nd position from the top instead of the bottom and will try that initially, knowing that it'll actually make it leaner. On startup after it's warmed up, I have a small, short screwdriver that I can adjust the idle jet as it's running, and of course the idle speed screw. Then I'll take it out and see how it performs, and look at the plug. I'll go from there, and adjust the E-clip on the jet needle accordingly. It's a beautiful blue bike with only about 3300km and other than the slight hesitation mid-throttle and a couple other very minor issues, the bike runs very well and is fun to ride.

[baroquenride]

I got a chance to tinker this past week but didn't ride it until today. This thing runs like a champ now! The hesitation I had before is gone which tells me I was running too rich. The stock jets with the E-clip in the 2nd position from the top on the jet needle, along with the idle jet around 1 turn out is the correct setting. The PO had it a little over 1-1/2 turns out and I've screwed it in about 3/4 of a turn with no adverse effects. Not only does it idle and start up better, but my seat-o-the-pants dyno seems to say it has slightly more hp. 15 ponies gallopin' at full throttle! My mpg's seemed to be about 55mpg running at mostly full throttle useage, which wasn't very good IMO so I'll be curious to see what I get now.

[DAVID THOMPSON]

keeping clean fuel in it and running it is best letting it set is hard on them
dave

[baroquenride]

I've got 5 other bikes at the moment. It's going to sit at some point but I'll turn the petcock off and run it dry so the jets don't clog.

[baroquenride]

I just saw this link on the VM-24 carb and thought it was an interesting read:
http://www.vintagebikebuilder.com/mikun ... guide.html

[Arnkatla]

Yeah this helpful http://www.vintagebikebuilder.com/mikun ... guide.html