40hp Mariner low on power

[thuggins]

So I have an 1989 Mariner 40ELO and it cranks and idles fine. Compression is good, spark is good and just cleaned the carburetor. The boat cranks and idles fine but when I take off it just isn't as fast as it used to be. Once on plane it will intermittently bog down and slow to a crawl, after a few seconds it will pick back up and go.

Any ideas? The fuel line and bulb are also less than a year old.

Thanks