hi all i have a 1990 dr650 to which i have fitted a mikuni tm40 carb,but trying to set it up is proving to be a nightmare. i can get the bike running but when opening the throttle sharply from tick-over [1500rpm] the engine either bogs and stalls or sometimes backfires through the air filter. above 2000rpm the engine seems fine. i have also noticed that if i set the tick-0ver to 1500rpm when the bike is stood on the sidestand and then stand the bike up dead vertical the tick-over goes up by about 500rpm. float hight too low?. any got any ideas please.