Not running properly on all 4

[joebloggs]

Try the easystart I suggested in an earlier post. If you can squirt it straight towards no 3 if will chime in if its got spark but no fuel. You said the carbs were cleaned but did you also check the diaphram's, I had a split on one on a GPZ600 and it gave similar symptoms. The slide wouldn't lift at lower RPM due to the vacuum leak but would lift as the engine speed increased.
A sticking float can also cause this, flooding the cylinder until the rev's build up although this often causes the engine to bog down then chime in like a twostroke