Hello. I have always the same problem. I have a hs87r trimmer, ms211c chainsaw, and hl95 long reach. I've replaced the diaphragm in all and now when I first start the machines from cold they won't respond to throttle untill they warm up a little. Then they run perfect, if I stop them and then restart then then they run fine. What could this be. They all have new sparks, ignition coil and magnet fine. When I say won't respond to throttle. I mean they are idling fine. Just won't rev up when throttle is pressed untill they warm up are I hold and realese the throttle. Any ideas will be appreciated!