Beleaguered but not defeated I carry on, trying to solve why #2 cylinder is not performing.
I have done as follows, including the reading on many related forums, thank you all for the insights.
Immersion cleaned carbs several times, verified visible tiny thru holes in body were clear,set float, replaced all jets, pilots ,seals and gaskets
Set valve lash, only notable was #2 Intake that was at .003 instead of .006 nominal
New Thermostat
New fuel lines and racor filter
New spark plugs
Synchronized carbs using Carb Tune device
swapped coils
Compression check hot and cold with throttle plates open = 90-100 psi
Engine performance is erratic. An Engine load test on stern of boat strapped on trailer, showed good pretty good burn on all cylinders.
However the sea trial did not go well it made 5000 plus rpm seemingly all firing, but 2500 rpm and down was very rough.
Even after the carb synch at home, the engine ran pretty well in the barrel but pulling # 2 wire made no difference in rpm.
#2 plug is wet the other two run a bit rich.
Wondering if the compression is too low for lower speed operation, but still don't understand #2 cylinder.
I am wondering if the top and mid carb can be interchanged to determine if problem is carb.
Any ideas or related experiences would be welcome
I have done as follows, including the reading on many related forums, thank you all for the insights.
Immersion cleaned carbs several times, verified visible tiny thru holes in body were clear,set float, replaced all jets, pilots ,seals and gaskets
Set valve lash, only notable was #2 Intake that was at .003 instead of .006 nominal
New Thermostat
New fuel lines and racor filter
New spark plugs
Synchronized carbs using Carb Tune device
swapped coils
Compression check hot and cold with throttle plates open = 90-100 psi
Engine performance is erratic. An Engine load test on stern of boat strapped on trailer, showed good pretty good burn on all cylinders.
However the sea trial did not go well it made 5000 plus rpm seemingly all firing, but 2500 rpm and down was very rough.
Even after the carb synch at home, the engine ran pretty well in the barrel but pulling # 2 wire made no difference in rpm.
#2 plug is wet the other two run a bit rich.
Wondering if the compression is too low for lower speed operation, but still don't understand #2 cylinder.
I am wondering if the top and mid carb can be interchanged to determine if problem is carb.
Any ideas or related experiences would be welcome
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