ORIGINAL: Switch_639

.....the engine has run before with no problems
... then I had a crash
... took apart the needles to clean them
... cleaned the carb
... after that the engine has flown twice with a big 14x8 prop
... then I changed to 12x8 and different pipe than standard and problems arouse (puffing)

(Beginning of thread)

... then I went back to 13x8 prop and stock muffler and now this problem came up
... the engine starts but seems to starve itself from fuel somehow
... now I've checked the tank pressure by taking it all out and closing all pipes blowing into tank, tank was fine no leaks
... so then after a while I got it running but once it goes beyond half throttle it dies
... no problems with fuel getting in at the needle
... glowplug is good
....fuel flow is good but its not getting sucked into carb

... could this be something to do with the bearings also? crankcase pressure being lost? I want to get diagnoses correct here... don't want to strip the whole engine down and in the end it was something smaller and easier...