Out on the lake today and my engine started acting up. Nothing has changed since the last time I ran it except:

I put a tuffskinz on my engine and I filled up with gas and oil today.

I have no idea what the problem is but the best way to describe

Cranking is fine no problems
Idling is fine no problems
Running at low RPMS is fine
Running at high RPMS is not fine....

When I'm WOT my boat runs around 53 loaded....
Tonight it would only go about 43...

You can tell that it's lagging and when it catches up and starts running good you can feel the motor cut out for a half a second..... It's really bothering me because I have a tourney on sat and there is no way I can have a mechanic check it out by sat am.

I don't think it's bad fuel because wouldn't it idle rough? Water pump is working I mean everything looks and appears as normal except for running fast the engine cuts out and slows way down...

Help! Any ideas??

Make shure that cover is not closing the air ducts off on the cowling.

It's not the cover

Coil pack

Powerhead

???