If it runs ok then its probably right. If it was 5mm or so out you would know. If I'm visualising it correctly the float would be very low and so would the fuel and it would be running very weak. The only experience I can recall on float heights was a Rotax Max 125 that was 2mm higher than it should have been and it was like it was running on half choke all the time. Probably best to leave alone!