2001 Challenger 1800 2.5 merc very strange bogging

[seadoo01]

So, I have a recently rebuilt Mercury 210 2.5 Sportjet (Carb). So when im out in the water after 15-20 of medium to high speeds, it will eventually bog, and it sounds like its somehow electronically limited. When I turn it off and let it sit for around 5 mins, it can go for another 20 or so then it repeats. This was a problem before the rebuild, and it still happens. Any thoughts?