The lsn is to rich, when ya gun it, it floods the engine momentarily, and as it transitions to hsn, you end up with a gob of fuel in it and then a heavy optimum air/fuel charge on top of it. When it is cool (before warmup)I would guess it does it worse, or even dies on you? Not a big deal, just lean the lsn 1/8 and see how it goes.