GageKirsch
New member
1990 mercury 75 jet (2 stroke 3 cyl)
I’m stumped on this one.. I’ve had this motor for about a year now and it’s been a dream. Starts up no matter the conditions and idles/ runs perfect, never skipping a beat. After every trip out it gets a fresh tank of oil and fuel.
On the river yesterday, ran about 20 miles up river and got about 15 miles back down when the motor fell on its face from full plane. Lost all power and seemed it was only running on a cyl or i sucked something into the jet. Checked the impeller and grate and nothing was lodged or sucked up, impeller spun fine like normal. Fuel prime ball was hard still and I wasn’t out of fuel. Turned the motor off quickly after it bogged and after looking around started it back up again, motor ran like it’s always ran for about 1 min and then bogged again like it lost cylinders. I took the foot off just to make sure I didn’t catch some fishing line on the shaft or anything and it was l clear. The next day, tore apart carbs, cleaned them good and nothing was out of the ordinary. Blew out all the fuel lines, new inline filters and checked tank breather and all the fuel system including pump, which was also good. Then to compression and all 3 were right around 118. Good spark on all 3 also. I ran it on the hose for a while and it ran great, thought I had fixed it and there was something gummed up.
Went out today to test it and I still got the same issue. No power, it’ll start with throttle but will die if let off. Good reed suction coming from all the carbs also. After doing some more spark tests all seemed normal. It’s peeing great like usual so I also figured it wouldn’t be anything with overheating.
Anybody have any idea? I’m going to test electronics next but I’m not sure where that will bring me. Thank you for anyone who’s here to help. It’s much appreciated!
I’m stumped on this one.. I’ve had this motor for about a year now and it’s been a dream. Starts up no matter the conditions and idles/ runs perfect, never skipping a beat. After every trip out it gets a fresh tank of oil and fuel.
On the river yesterday, ran about 20 miles up river and got about 15 miles back down when the motor fell on its face from full plane. Lost all power and seemed it was only running on a cyl or i sucked something into the jet. Checked the impeller and grate and nothing was lodged or sucked up, impeller spun fine like normal. Fuel prime ball was hard still and I wasn’t out of fuel. Turned the motor off quickly after it bogged and after looking around started it back up again, motor ran like it’s always ran for about 1 min and then bogged again like it lost cylinders. I took the foot off just to make sure I didn’t catch some fishing line on the shaft or anything and it was l clear. The next day, tore apart carbs, cleaned them good and nothing was out of the ordinary. Blew out all the fuel lines, new inline filters and checked tank breather and all the fuel system including pump, which was also good. Then to compression and all 3 were right around 118. Good spark on all 3 also. I ran it on the hose for a while and it ran great, thought I had fixed it and there was something gummed up.
Went out today to test it and I still got the same issue. No power, it’ll start with throttle but will die if let off. Good reed suction coming from all the carbs also. After doing some more spark tests all seemed normal. It’s peeing great like usual so I also figured it wouldn’t be anything with overheating.
Anybody have any idea? I’m going to test electronics next but I’m not sure where that will bring me. Thank you for anyone who’s here to help. It’s much appreciated!