I HAVE RECENTLY BOUGHT A SHERCO 290, BUT HAVE TROUBLE STARTING FROM COLD IVE REPLACED THE SPARK PLUG , AIR FILTER & REPLACED THE FUEL, STRIPPED / CLEANED OUT THE CARB. SPARK APPEARS OK. IT DOES START WITH A QUICK SPRAY OF EASY START & WILL FIRE UP FINE WHEN WARM. ANY IDEAS WOULD BE MUCH APPRECIATED.