i just changed the oil put in regular repsol 10-40 oil in to the exact suzuki spec. the level is bang on . so i have the motor warm and i come back and rev it and start noticing a little puffs of black smoke out the exhaust pipe when i give it a good little rev. is this normal for a carburator? i mean i dont think i have ever seen smoke coming from the exhaust. i know for a fact i did not overfill the oil so i wonder what it could be:bonk: ? should i be looking for something else? could it be the jetting?