1990 Johnson 88 spl bogging down when full throttle??

I got a "free" boat from a friend of a friend, just about a thousand bucks into it now and got most of the bugs out. Cleaned the carbs, replaced the starter, new plugs, drained the fuel, replaced impeller, replaced lower unit lube. Its got good compression, good spark starts good, idles good when warm, shifts smooth. When running wide open it runs like a champ for about 30 seconds then suddenly seems to just bog down. If I shift into neutral it usually recovers and then operates like normal. Any one got any ideas of where to start. It kinda sounds like the fuel suddenly runs out. Yesterday a friend was riding with me and we were trolling for a while at medium speed and it started to act up and he squeezed the primer ball and it recovered normal operation quickly. Im thinking its an air leak in the fuel line or a bad fuel pump. Any other ideas, could it be a timing issue?

Re: 1990 Johnson 88 spl bogging down when full throttle??

Sounds like you're on the right track with fuel. Have you checked the vent in the fuel tank?

Re: 1990 Johnson 88 spl bogging down when full throttle??

Ironically the vent cap looked like someone had rubbed it on the concrete to make a hole in it for extra air, I thought that I would fix it by putting some martex expoxy on it to fill the rub mark. Guess I will pick up a new vent cap when I get the fuel pump rebuild kit. Thanks.

Re: 1990 Johnson 88 spl bogging down when full throttle??

Just in case any one else reads this it was a faulty spark plug wire, $7 part and she is running fine now.