At a loss. Front cylinder losses spark when warm
Last fall I replaced stator, pickups. The bike ran great parked it for winter. Started it this spring let it idle till I warmed up,. Once warm the tachometer died and I lost spark in front cylinder. I cleaned connections for front ignition coil. Bike cooled started ran fine. Warmed up and it sputtered failed again. Tried once more. Blew rad hose under the gas tank. I replaced all hoses. Replaced with new OEM ignition coil today and the bike runs great till warm and then tach dies and no spark in front cylinder. If I leave it to cool down for a bit it run fine. It doesn't even get that hot before it acts up.The rear runs fine. Any clues would be great.