My 2.4 was a PITA to start yesterday, thought I had flooded it. Finally get it running and the transition seems a tad sluggish so I leaned the low needle a hair. (Just got it back from a full service - was thinking that needles might need a mild tweak to compensate for the difference in locales.) I have 3 flights on it since the service with no issues. Once in the air the engine was pulling my 15lb CG Yak like always - nice strong performance on a 20 x 8 Xoar prop. I flew for 6-8 mins and all was fine, good throttle response coming out of downlines and all. Then I put it into an inverted flatspin and about 3 rotations in the engine bogs. I roll out and fly wings level for a bit and the engine finally cleaned up (after 15-25 seconds). I come around to land and it won't idle down low enough to land, so I go around and drop my throttle trim several clicks (5-6). I put the yak on the ground and then the engine is just about dying the idle comes down so low, and has trouble coming back up to taxi in to the pits.

Next flight I fire the engine up - it hits on the 5th flip without having to re-choke, and seems to transition decently on the ground. High end is nice, so I taxi out, blow the motor out and get it into the air - full throttle climb out, and as soon as I get about 15 degrees nose-up, the engine drops RPM again on me, but thankfully is still pulling the plane well enough to avoid a stall. I circle and land it, and the engine dies on rollout when I try advancing the throttle.

I'm thinking that my LSN was lean to begin with, and I made a mistake by leaning it more. Cool 45 degree day (dense air) probably wasn't helping any. I'm going to richen it up a bit and do a lot of ground testing this week see how it runs. Also planning on going through all of my fuel tubing/clunks. Will also pull the cover off the diaphragm and check it for any cracks/tears/pinholes. Anything I'm missing?