Its all to do with the jetting.
The idle circuit in particular is very finicky to get dialled in. If it idles for a minute call it good. It doesn't want to sit around idling all day.
Try turning in the black plastic screw on the LHS of the carb a bit. Its your idle screw and will raise the idle a touch more.
If the engine races up a bit before it cuts out you might be a touch lean on the pilot. I'd say more likley is that you're slightly rich and after a minute the engine loads up a bit and stalls out. Not enough to foul the plug, but enough to not be ideal idling conditions anymore.
|