Mariner Super Magnum 200 problems running HELP

[NGAbullet98]

I recently had my 200 Mariner super magnum rebuilt after it sat torn apart for almost 10 years. Had it professionally built here in north ga. Motor runs great, can tell it’s got the power, and idles perfect. The problem is when you take off and hit 3000 rpms coming out of the hole it’ll cut out it sounds like ( not the prop biting ) but after it hits 3000 rpms it’ll launch and take off. Currently still am in break in period so I have 7 hours out of 10 at 4000 rpms. Well once you run it a while at 4K it’ll start cutting out worse than it is when you’re running ( can barley feel it when you’re running ) then you can flat foot it and it won’t go over 4000 rpms. Have had the engine gone through and tested and what’s funny is everything checks out. Even when it was cutting out skipping the test light never showed it. Did a fuel pressure test while it was running and and stayed around 38. Only hint we seen was my timing was set to 22degrees and when we took off it jumped to 35!! When I figure it should’ve only went to 23-34. With all the tests we did coming back fine it’s about to the point to just start changing out parts and praying... but at idle it’s fine got great fire but maybe it’s the trigger causing it to jump spark once it’s under a load? Or maybe the high side of a stator? I’m new to this electrical part of the motor. Any help would be greatly appreciated thank you!

[EuropeanAM]

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