Hi guys new to the forum with a very stubborn YR5. I've totally rebuilt the motor after buying the bike as a non runner. Rebore pistons crank all the ignition and charging system a new Motobatt battery plus the carbs ultrasonic cleaned and checked. The problem is when I go out for a run the bike starts and ticks over fine but two miles of so into the run the bike either packs in altogether or drops onto one cylinder first and then stops and won't restart. Checking straight away the bike has a good spark on both sides and the plugs are wet but won't start? I push the bike home and it still won't start but if I leave it overnight it starts and runs perfect until I go for a run and the whole saga starts again. Oh plus even running with the filler cap removed makes no difference.
Any suggestions welcome before I give it a Viking funeral