CONTINUOUSWAVE

My 1998 Mercury 135HP 6 cylinder engine runs fine at higher RPM but dies when brought back to idle. Launched the boat yesterday and ran it at 2500 RPM for about 20 minutes before pulling back to idle. It ran for about 2 minutes at 800 RPM before slowly decreasing to below 600 RPMs sputtering and dying. Despite being warmed up, it wouldn’t start back up until I let it sit for a couple minutes and heavily reprimed but it still wouldn’t run at idle.

Just had the boat in over the winter for replacement of the infamous plastic drive gear for the oil injection system. Any thoughts on likely cause of problem?

Is this the carburetor version or the direct fuel injection (OptiMax) model? My review of the parts list on Crowley Marine indicate that both models were available in 1998.

M

How old is the gasoline fuel in the fuel tank?