I have a 1999 Sea Ray F16 with the Mercury XR2 175. I hope I am posting this issue in the right spot.
The boat has an estimated 85 hours and last year ran very well the first couple of trips. A dead battery cut the third trip short. The next trip the boat would not crack over unless it was given a little gas while cranking. It was parked without running out the gas and I am unable to get ethanol free gas in my area. I know this was not good when it would not start this year. Here is a quick summary of what I have done so far this year.
* New gas with sta-bil ethanol treatment
* Checked anti-syphon valve
* Cleaned carburetors (3) with spray
The last step seemed to do the trick after giving the carbs a little extra choke. After it burned off all the cleaner I noticed the engine seemed to sound much different. I must note here I was running it out of the water with the hose in the flush attachment momentarily to see if it would start before dragging to the lake. The reason the engine sounded different, however, is because it appears to be running at close to full throttle even with the throttle in the neutral, idle position. My first guess was a stuck float, but I can find no mention of this being a symptom of a stuck float. Before removing the carbs and going through that process I would like to know if that is likely the problem. Has anyone experienced this with a stuck float on this or any engine, or is there another likely explanation?