Cylinder 3 misfire at low revs

[Whomightyoube]

Just got myself an ultrasonic cleaner for a recommissioning of an old XJR400. Cleaned an amazing amount of shite out the carbs, look good as new! Just got to rebuild them and try them. Carb cleaner just would t remove the varnish

So do you recon that I just didn't clean the carb out fully? I was wondering if I should have ditched all the old petrol and completely flushed the tank. I sprayed cleaner into all the orifces and blew out with air. Same with all the jets. Pilot jets are very small. If there is crap in the petrol then wouldn't all the carbs be affected, not just no 3 all the time?