115 Merc bogging down then revving up

[navymustang]

I have a 1989 mercury 115 hp. It was running great, then last week when I went on the river, I was at WOT and the engine suddenly bogged down, then picked back up. It continued to do this as i headed to my destination. When I stopped the boat, it died. I pumped the bulb and it started right back up. Went back up to full throttle, and ran fine for a few minutes, then started losing power again. Here's what I've tried so far....

1. Changed bulb......same problem
2. Ran new fuel line straight to tank (bypassed water seperator)....same prob.

It seems like it's burning the initial fuel that is pumped in with the primed bulb but isn't getting enough fuel after that. Any ideas????

Mike

 

[sschefer]

Re: 115 Merc bogging down then revving up

Mike, couple of questions:

1. Are you still running oil injection or are you mixing gas.
2. Did your remove the inline fuel filter when you put the fuel/water separator in?

 

[navymustang]

Re: 115 Merc bogging down then revving up

No, the oil injection system was removed before I bought it. I've just been mixing the fuel in the tank. It's been running perfect for the last three tanks. Also, the only filter i'm using is the fuel/water separater. I first thought it was the separater since I didn't have this problem until i installed it. But I ran a new line straight from the tank to the motor and still the same problem.