Hi All,
As stated above I have a 1982 Mercury 50 HP 2 Stroke with the Thunderbolt Ignition. I recently did some repairs (replaced trigger, replaced stator, cleaned carbs) Upon reassembly, it starts nicely as before, but doesn't fully rev up when under load. I looked at the carbs and noticed that the butterfly valves are only opening about 40% when throttle is full. Did I install the carbs incorrectly?
The top of the top carb has a lever that is shaped like a U with the bottom of the U linked to the butterfly. Rotating the U shaped lever opens the butterfly valve and when you open the throttle a mechanism pushes on that U shaped lever to operate the butterfly. First it pushes on the right side of the U and then when fully throttling up a second piece of the mechanism catches the left side of the U to continue opening the butterfly valve more. This second piece of the mechanism has an adjustable locking screw which interacts with the left side of that U shaped lever, so It seems like the pieces are operating together in a way that makes sense to my brain with two exceptions.
Ilde -
Full Throttle -
#1. At Idle speed adjustments to the throttle, the mechanism doesn't touch the U shaped lever. Only the trigger moves at low throttle. Is this correct? Do the old mercs control idle speed with the trigger advance alone? or should the butterfly be opening as well as the trigger advance?
#2. At full throttle, the butterfly is nowhere near full open. Is that right? Seems to me least very close.
I would really appreciate expert help with this!
Side question. At TDC, should the timing indicator on the flywheel be at 0? The monopoly on outboard manuals is very frustrating.....
As stated above I have a 1982 Mercury 50 HP 2 Stroke with the Thunderbolt Ignition. I recently did some repairs (replaced trigger, replaced stator, cleaned carbs) Upon reassembly, it starts nicely as before, but doesn't fully rev up when under load. I looked at the carbs and noticed that the butterfly valves are only opening about 40% when throttle is full. Did I install the carbs incorrectly?
The top of the top carb has a lever that is shaped like a U with the bottom of the U linked to the butterfly. Rotating the U shaped lever opens the butterfly valve and when you open the throttle a mechanism pushes on that U shaped lever to operate the butterfly. First it pushes on the right side of the U and then when fully throttling up a second piece of the mechanism catches the left side of the U to continue opening the butterfly valve more. This second piece of the mechanism has an adjustable locking screw which interacts with the left side of that U shaped lever, so It seems like the pieces are operating together in a way that makes sense to my brain with two exceptions.
Ilde -
Full Throttle -
#1. At Idle speed adjustments to the throttle, the mechanism doesn't touch the U shaped lever. Only the trigger moves at low throttle. Is this correct? Do the old mercs control idle speed with the trigger advance alone? or should the butterfly be opening as well as the trigger advance?
#2. At full throttle, the butterfly is nowhere near full open. Is that right? Seems to me least very close.
I would really appreciate expert help with this!
Side question. At TDC, should the timing indicator on the flywheel be at 0? The monopoly on outboard manuals is very frustrating.....