Trimmer starts good, boogs down when given gas?

Do you mean it simply wont accelerate?
Screw both H & L fully in, then 2 full turns out will give you an approx factory setting.
From there start her up, throttle fully open turn the H screw clockwise until she is revving at max then give her about 1/8th turn more, this will drop the revs slighty but give you better torque when it hits the green stuff.
L adjustment, easy, just move the screw until its going hard again, then it will be a case of moving the idle screw so the head isnt spinning.
This should give you a a fairly decent set up moving from idle to max without any bogging.
Hope Ive not confused you.
Andy
PS if your machine still has the plastic caps on the H and L screws cut them off, they are only there for fuel emission standards when it left the factory, they are more of a nuisance then anything and no real carb adjustment can take place with them on. Removing them should not effect warranty, however if the machine is still new then double check.

I gave this answer to someone else, Im almost certain this will apply to your machine.

andy
May 2009