I have a 96 Mariner 150 that smokes badly and runs rough at idle. Runs great when at full throttle. Any suggestions on the cause of this problem ? Is this a simple carb rebuild or maybe a more serious motor problem ?
Oil injection working properly? Old or contaminated fuel? What's the history of the motor? Been tuned lately? Ever overheated? Carbs ever rebuilt? Possible sticky needle and seat on one or more carbs. What have you checked?
I bought the boat like this. Have not had much time to really look at anything yet. Looking for a starting place. It runs great after you put it in nuetral and rev it to clear the carbs. runs rough again after you bring it off plane and back to idle. Gas is o.k not sure about the oil injection.I guess I am looking for obvious stuff first to use as a starting point.
Since you have no idea what condition the engine is in mechanically, you need to do the basics. Start with a compression check. Then a spark check. Do a decarb. Then rebuild the carbs. Replace the impeller and thermostat. Follow all of that with a link& sync. And before you do any of this, buy a manual for the engine. All of those procedures are way to detailed to go into here.
It's showing signs of either being "tired" or in need of a decarb. It will run ok with compression at those numbers but will not develop power that a fresh engine would have.
My 87 Merc 150 has compression readings of 120 all the way accross and it has a lot of hours on it. It also runs what I would consider "Rough" comparing to what the newer EFI engines sound like. It also stumbles a bit when accelerating. I think this is pretty common from what I have encountered over the last 20 years.
I think you do need to follow the decarb procedures you can find here on the forums. SeaFoam seems to be the ticket.
Use regular 87 fuel, and after the decarb and new plugs, I would use a full synthetic oil to help with less carbon buildup.
1996 Mariner 150 carb problems ?????
HUMAN BUILT = HUMAN FIXED
CERTIFIED MARINE TECH
Linear Mode
