Originally Posted by MTK

Several years ago when I was new to gassies, I noticed that when to LS needle was set a bit lean, the engine just wouldn't transition right. It would often die ; it woulnt die every time so this threw me a little. I did a little bench running and realized that the LS didn't need much richening to stay running but it needed some. This became my tuning procedure since then.....turn the LS in until it wouldn't transition and richen from there about the width of a screwdriver at a time until transition cleaned up. The setting of course would be revisited as the HS Needle was tuned. This procedure was discovered on an OS33 but has been applied on all of my gassies from 15cc to 58cc withe same good results.

edit: Walbros only......forgot to mention an important action. Throttle advancing through midrange needs to be very fast. A Lean low end will nearly always die. Richening a bit cleans things up.