found this:
.28 EX engine settings Low speed needle clockwsie till stop, back out counter clockwise 3.5-4 turns
.28 EX engine Settings High speed needle clockwise till stop, back out counter clockwise 2.5
these settings are very rich. If you are still having trouble starting then adjust clockwise (tighten) by 1 hour increments. 1 hour increments meaning if the screw was a clock with 12 hours, adjust by 1 hour clicks.
If any engine isnt starting check the fuel lines for fuel. If not fuel then PRIME the engine. To PRIME the engine cover the intake or exhaust port with finger. Pull cord a couple of times until fuel runs into carb. Then proceed to start.
If engine is still not starting check carb opening. Too closed wont start. Too open hard to start and if it does it will be high idle. Adjust the carb opening with the IDLE SCREW. Remember for the IDLE SCREW clockwise is to OPEN. Counterclockwise is to CLOSE. Proper carb opening is usually .8mm or 1mm.
If engine still not starting check and re check glow plug and glow plug ignitor to ensure they are working properly.
If the pull cord is hard to pull then the engine is flooded. Remove glow plug and dump fuel out or pull cord to pump fuel out. Reinstall glow plug and check above settings.
If you are still having trouble starting check your fuel. Is it really old? Recommend to have 20% nitro methane content.
If you are still having trouble starting then check for leaks in the fuel lines, Leaks on the cooling head? screws tight? carb is bolted down tightlly?