I have a 2005 115hp 2+2 Merc, probably one of the last one's made, just my luck.
This motor runs great, but starts & idles poorly.
Last year my wife and I put on over 800 miles averaging about 3.5mpg per the GPS on several of the Southern waterways. Above idle, this motor runs great, never a miss, sputter, etc.
Its cantankerous when starting, sometimes at the touch of the key, other times it may take several attempts, never predictable, warm, cold, unpredictable starts. Sometimes it idles good, sometimes(usually) it doesn't. Seems like it runs rich at idle, some noticeable blue smoke.
The question I have is how smooth should this engine idle? What are the experiences of other owners of these 2+2? Did Mercury make a motor that idled so poorly, or is it just mine?
Things I've tried: (note this was before the 800 mile run last summer)
Removed and disassembled all 4 carbs( I know, only 2 have idle adjust) blew air through every visible passage way, adjusted the floats, put all back together.
Adjusted the idle screws many times, seems like 1 1/8 to 1 1/4 works about the best.
Motor runs well, just doesn't idle smooth, and starts hard.
The one other observation is that the type of gas seems to make a difference. I'll generally fill up before going to lake/river while boat is still on trailer and its likely that it's gas with the ethanol mix. Later that day while on the water I'll fill up at a marina and I believe the gas doesn't include ethanol, and/or may be a premium (sure costs more). Idle often needs adjusting after a fill, other times no difference.
I noticed in the shop manual that there is a oil injection pump adjustment but it doesn't seem to be clear to me. Anyone have suggestions on if oil pump needs adjusting and how? Again, there seems to be blue smoke at idle at times, but not all times?
So spring is around the corner... anyone have suggestions?
Thanks in advance, CPS22
This motor runs great, but starts & idles poorly.
Last year my wife and I put on over 800 miles averaging about 3.5mpg per the GPS on several of the Southern waterways. Above idle, this motor runs great, never a miss, sputter, etc.
Its cantankerous when starting, sometimes at the touch of the key, other times it may take several attempts, never predictable, warm, cold, unpredictable starts. Sometimes it idles good, sometimes(usually) it doesn't. Seems like it runs rich at idle, some noticeable blue smoke.
The question I have is how smooth should this engine idle? What are the experiences of other owners of these 2+2? Did Mercury make a motor that idled so poorly, or is it just mine?
Things I've tried: (note this was before the 800 mile run last summer)
Removed and disassembled all 4 carbs( I know, only 2 have idle adjust) blew air through every visible passage way, adjusted the floats, put all back together.
Adjusted the idle screws many times, seems like 1 1/8 to 1 1/4 works about the best.
Motor runs well, just doesn't idle smooth, and starts hard.
The one other observation is that the type of gas seems to make a difference. I'll generally fill up before going to lake/river while boat is still on trailer and its likely that it's gas with the ethanol mix. Later that day while on the water I'll fill up at a marina and I believe the gas doesn't include ethanol, and/or may be a premium (sure costs more). Idle often needs adjusting after a fill, other times no difference.
I noticed in the shop manual that there is a oil injection pump adjustment but it doesn't seem to be clear to me. Anyone have suggestions on if oil pump needs adjusting and how? Again, there seems to be blue smoke at idle at times, but not all times?
So spring is around the corner... anyone have suggestions?
Thanks in advance, CPS22