1994 115 hp down on power

I'm working on a friend's 115 (serial OG213348)and while familiar with OMCs, my experience with Mercs is limited. The engine idles like it is missing a cylinder yet a timing light shows good even fire across the plugs (new plugs, wires and fuel filter.) It was barely idling at 250 rpm, I idled it way up to 600 but the idle is very rough. The engine lacks the power to stay running when put into gear in the water (will stay running out of the water.) It has sat for a while so I ran it on a jug of fresh gas for a while with no change. A can of carb cleaner netted no real change. The fuel bulb stays firm and pumping it does not change the idle or run (thought the fuel pump might have had a tear/hole.)I pulled the plugs and they appear to be burning equally and were wet. Any other ideas?

Re: 1994 115 down on power

dirty carbs and check compression. After the carbs are cleaned set the idle mixture.

Re: 1994 115 down on power

This is tough one if you are not familiar with Merc's 2+4 system. If it wont idle than that can almost only be the #1 and #2 cylinders not getting gas or spark. I would clean all the cabs and rebuild the fuel pump. And set the linkages exactly by the book. #3 and #4 do not pull enough gas at idle to have a combustible mixture under 1800 RPM.

There is an accerator pump to bridge the gap so it does not bog down. Those nozzles are hidden behind the oil bottle.

Re: 1994 115 down on power

firt you need to test compression of the cylinders, you need the test power of the sparks,
see if the seals are in good condittions. and the reed valve is close.