New to me grady with twin 89 black max 200's first trip out i lose starboard motor and am able to make it home on port running at about 2000 rpms. running port motor harder it seemed to be losing power also. I made it back loaded it on the trailer hauled it home gave it its bath and flushed the motors. the starboard motor fired right up by unpluging and switching fuel lines. next trip to the boat i found both fuel lines from seperator to motors to be very deteriorated on the insides with pieces of the hoses clogging the quick connect at the motor. I replaced both water seperator filters replaced both lines to motors and both filters on the motors and cleaned both ends of quick disconnects. I also dumped the fuel from the filters into clear container to inspect for dirt and water and found it to be good. 2nd trip out about 6 miles into a 20 mile run the port motor begins falling off, never stalling but rpms fluctuating between about 2000 and 4000 with control wide open. sometimes it would hang at 2000 and other times it would jump up and down at 3-5 second intervals. stubborn me, I continue my 20 mile run in which i tried switching fuel tanks, pumping the ball and cracking the gas cap loose. Nothing seemed to help. putting both motors on 2000 rpms i continued on. anchor up for about 3 hours and fire it up for the dreaded trip home and both motors hold a steady 4000 rmps the full 20 miles. after backing down to enter inlet the port engine again starts fluctuating but its not as easy to feel running at a lesser throttle. Trailer home and give her a bath and flush motors. pull quick connects apart and look for debris and pull port fuel pump apart to inspect for condition and dirt nothing noticed
old 1989 mercury blackmax 200s
new power heads in 2005
oil injection removed and premixed at 50.1
both fuel tanks replaced
new fuel fill and supply lines
noticed port engine temp guage at 3/4 while starboard dead center
Plans for next trip down to the boat
compression check
remove and double check anti siphon valves
vaccum fuel lines to check for air leaks
change spark plugs
So i'm looking for any ideas you guys may have for me to also check. i sure dont want to keep pressing my luck and it also dont seem like something I can duplicate on hose connection running out of the water with no load.
Sincere thanks to any suggestions
old 1989 mercury blackmax 200s
new power heads in 2005
oil injection removed and premixed at 50.1
both fuel tanks replaced
new fuel fill and supply lines
noticed port engine temp guage at 3/4 while starboard dead center
Plans for next trip down to the boat
compression check
remove and double check anti siphon valves
vaccum fuel lines to check for air leaks
change spark plugs
So i'm looking for any ideas you guys may have for me to also check. i sure dont want to keep pressing my luck and it also dont seem like something I can duplicate on hose connection running out of the water with no load.
Sincere thanks to any suggestions