!993 Evinrude (OMC) Evinrude runs rough at lower RPMs

[gtdavis]

Hello all, been a while since I have been on here. Just entered a new to me boating experience. I bought a 1993 Sylvan 20 foot pontoon with a 60 hp Evinrude OMC. I do not have any technical info like compression or spark tests but let me tell you what I do know, After I discovered the magic push button choke on the ignition switch it literally fires up with a bump of the key. It idles fine does not seem to misfire at all. When I put it in gear it starts running rough until I hit 2500-3000 rpm then takes off. Moves the toon at around 20-23 mph per gps at WOT and that's with a badly chewed up prop. I am assuming it is a carb issue but was wondering if there is anything else I can do or need to check before I go diving into the carbs, Thanks in advance!

 

[gtdavis]

Ok a little update, I checked the fuel mixture screw they were all off a little, also checked the throttle linkage and it is on the mark and it appears the butterflies are opening and closing correctly and at the same time. unfortunately I dont have a compression tester or timing light to check those things. I did notice at low RMP and idle my console tach is kinda all over the place....it will move up to 4k and the motor is still at idle. According to the on the console its idling at around 1800 but without the proper tools cant know for sure Getting ready to change the plugs as soon as it cools down a bit. Starts and goes way too good....has to be something simple. Any help would be appreciated!!.

 

[gtdavis]

Ok a little update, I checked the fuel mixture screw they were all off a little (I adjusted them all to 1.5 turns out), also checked the throttle linkage and it is on the mark and it appears the butterflies are opening and closing correctly and at the same time. unfortunately I dont have a compression tester or timing light to check those things. I did notice at low RMP and idle my console tach is kinda all over the place....it will move up to 4k and the motor is still at idle. According to the on the console its idling at around 1800 but without the proper tools cant know for sure Getting ready to change the plugs as soon as it cools down a bit. Starts and goes way too good....has to be something simple. Any help would be appreciated!!.

 

[racerone]

edit

 

[racerone]

Can not give any advice till compression values are posted.----------These engines have a history of problems with # 2 cylinder.

 

[gtdavis]

my lack of knowledge with outboards is pretty obvious. It starts good and runs strong just idles and runs rough at low rpms I would think a compression issue would not allow those two things but I will see if I can round up a compression tester and get those numbers,,,,, Is there anything in the meantime I can look at

 

[racerone]

Sorry , but a compression test is step # 1 in trouble shooting of an outboard motor.----There have been issues with these motors with scoring the piston on the #2 cylinder.----Guessing and assumiing just does not work on these motors.

 

[gtdavis]

No need to apologize!!!! I learn by asking questions...I learned A LOT about by 3.0 Merc with this forum (kinda wishing I had it back right now :blue:
Hopefully a buddy of mine will come through tomorrow with a compression tester. Otherwise Ill need to order one.