Picked up a 1994 Sizuki Intruder 800. HadnĀ“t been run for a few years. Replaced the battery and plugs. Started but only the rear cylinder is firing. Check for spark on the front cylinder and looks the same as the rear. Apears fuel is getting to the front but it is not firing. Gap on plugs is correct on both plugs. Any idea what might be the cause or any adjustments that might be made?