1988 Mercury 35hp

[Kevin777]

I have a small 17’ Bass Tracker I just picked up and motor is giving me some issues. It’s a 1988 Merc 35hp with serial #OB342291. It wasn’t running good and I didn’t know how long it sat so I replaced fuel, fuel line and disconnected the auto oiler and just mixed the gas. It was running good and holding idle for two days. Now it has gone back to running poorly and not holding idle at all. I have a compression gauge and it’s showing good compression (125 & 135).

I’m guessing it’s either fuel pump or carb but just wanted to get other opinions since it seems intermittent.

[silvertalon]

Are you in the water under a load -at idle when this happens or, is it running on flush muffs and water hose? You need to check spark on both plug wires with a timing light. Could be dropping fire on 1 cyl... If it's running on the hose, it will probably run on 1 cylinder. If in the water it would probably die running on 1 cyl... Otherwise, clean the carb out good and try again. I would also get a spray can of power tune and load up the motor real good while running at about 1,200-1,500 rpm. Wait 2-3 hours or overnight and run it wide open (in the lake), for a spell.