I have a 7port with about 4 gallons on it now maybe 4 1/2...... I am running Odonnell's 30% with a OD97T plug and 053 pipe with 8mm carb insert. all this in my 8ight buggy. I am not able to get more then 7mins of run time.... trying to get 7:30 for half way of 15min race... ran out of fuel 3 times trying to do that.... how much time can I knock off with say a 7mm insert ? and how much power will I lose ?

Thanks