Mariner/ Mercury 60 Bigfoot 4 stroke, 2007 Model

Hi everyone

I am new to the forum and from South Africa

I recently bought a 17ft boat fitted with a pair of 60 Bigfoot 4 strokes, when i got the boat the engines had around 700 hours on them and since then i have put on an additional 100 hours or so.

The last time i was out the one engine was not making max rpm of around 5400, it would not make over 4000 and every few second it would drag down to 3000 and then immediatly back up to 4000 odd rpm, and continued to do this for around 10 miles that i was running the engine full speed, i have not used the boat since then and am wondering what the problem could be? Dirty injectors perhaps? Can someone please help me?

Thanks
Don

Another thing, can anyone with the same engine/s perhaps give me some feedback of their experiences with these engines be it good or bad!

Don't own the motor and don't know anyone that does.

Your issue sounds like a bad fuel pump (early stages of death), but could also be a clog in a filter, air or water in the gas line...

If the motors are running from a common gas tank you may want to switch around the gas lines and see if the problem moves. That will quickly tell you if it's the gas line (or some component of it) that is the issue.

If the same motor continues to act up I would change any filters (under the hood)...

thanks! the engines were serviced around 60 hours ago and new filters fitted, i also recently installed a raycor inline water seperator.

I will try changing over fuel lines next time to see if the problem persists!