On three week leave up in Canada, merc has problem, Local dealer said to park in lot and he may get at it next week to see what the problem is.
HELP...family not empressed with dad
This is a 1985 Mercury V200 oil injected Black Max, serial 6493895.
Run boat when first got here it run perfect. When new this boat pushed 21 invader at 68 mph top speed, over the years it has dropped to about 55. new plugs and oil, grease every year never damaged always clean, total of about 700 hours fresh water only. Two nights ago was comming back to camping spot and the boat turned on like new, ran at 5800RPM and 68 MPH on speed o. Couldn't believe it. Ran at full for about three -four minutes and droped to cruize and headed in. went to take son's fishing in morning...the boat ran perfect till tried to get up on step. NO POWER, boat would not rev. no block noise, no sounds, pisser showing good cooling flow. Took boat to local dealer...says he's busy till end next week...park it and get in line.
Checked compressiojn...125-130 all six, all plugs looked good, but heavy oil on plugs one and two.
Can start and run perfect with cooling muffs on. run up to 3500RPM no problem sounds perfect, push in choke and boggs, so don't think is choke. flushed and changed al gas. checked all carbs for plates closing, seams to be good. Need help fast to save vacation.
ANY Thoughts, please...if dealer and have answer give phone number will get to you asap. parts what ever... need help!!!

It could be a fuel or ignition problem.
The factory fuel pumps are notoriously bad. The diaphram usually tears reducing fuel pressure. Also replace the check valves. All these parts come in a fuel pump repair kit. Easy to do yourself.
Or, it could be ignition, harder to diagnose.
It's either your stator (most likely) or one or both switch boxes.
Good luck.
Steve

check ignition with spark checker. The stator on the older merc have 2 charge coils. One does high speed and the other does low speed.

Go for a ride and pump the primer ball and see if revs pick up to rule out a fuel problem.