Model and history:
I've got a 4-cylinder, 75hp 1986 Mariner with good compression. Had an oil injection system which I removed and now mix fuel and oil. Compression +/_ 153, 151, 152, 146. Paid someone to check the stator, because it was hard starting and ran a little rough at low speeds. They said stator was fine and did minor adjust to carb. Ran a little better. Still hard to start. Last winter, I rebuilt the fuel pump, water pump and carbs. Something isn't quite right about the carbs.
Carb problems:
Wants to bog down or die coming out of idle speed. Does great at wide open throttle (WOT). In other words you have to jam-it into something close to WOT coming out of idle in order to pull a tube with two kids. Tends to stall in reverse as well. Have set the idle screws at mid-point/sweet spot and backed them up 1/4 turn. That seems good. It's a dual carb, but I was careful to allign them so that they closed at precisely the same moment. Don't detect any leaks in the fuel system at this point. Idle RPM's appear OK. Plugs tend to run oily. It's also pretty smokey, but maybe I'm just not used to 2-cycle engines.
Given the symptoms, and maybe the smell too, it seems as though the motor is getting too little air or too much fuel. This leaves me with two questions and a request for any advice you might have:
1) The throttle plate is completely shut at idle. Is this normal or should they be slightly open to allow more air?
2) Float level seemed to be as spec'd during rebuild but, I'm thinking about bending the tangs to hold back the fuel flow a bit. Would this be wise. Would it hurt to try?
Hoping someone can help.
I've got a 4-cylinder, 75hp 1986 Mariner with good compression. Had an oil injection system which I removed and now mix fuel and oil. Compression +/_ 153, 151, 152, 146. Paid someone to check the stator, because it was hard starting and ran a little rough at low speeds. They said stator was fine and did minor adjust to carb. Ran a little better. Still hard to start. Last winter, I rebuilt the fuel pump, water pump and carbs. Something isn't quite right about the carbs.
Carb problems:
Wants to bog down or die coming out of idle speed. Does great at wide open throttle (WOT). In other words you have to jam-it into something close to WOT coming out of idle in order to pull a tube with two kids. Tends to stall in reverse as well. Have set the idle screws at mid-point/sweet spot and backed them up 1/4 turn. That seems good. It's a dual carb, but I was careful to allign them so that they closed at precisely the same moment. Don't detect any leaks in the fuel system at this point. Idle RPM's appear OK. Plugs tend to run oily. It's also pretty smokey, but maybe I'm just not used to 2-cycle engines.
Given the symptoms, and maybe the smell too, it seems as though the motor is getting too little air or too much fuel. This leaves me with two questions and a request for any advice you might have:
1) The throttle plate is completely shut at idle. Is this normal or should they be slightly open to allow more air?
2) Float level seemed to be as spec'd during rebuild but, I'm thinking about bending the tangs to hold back the fuel flow a bit. Would this be wise. Would it hurt to try?
Hoping someone can help.