1983 mercury 80hp timing and idle questions

I have a 1983 80 hp 4 cyl sn 07204275

Using screwdriver to test depth in cylinder 1, I have confirmed that the timing pointer and marks line up with TDC ( +/- 5%) since I can't be precise.
I have good spark on each cyl ( jumps ¼ in gap).
And confirmed with timing light that each cyl is firing at proper time.
I did static timing adjustment andI set timing according to what was written on motor (idle at 4 Atdc and max at 30 Btdc-cranking). Went to try in water but would not start at those setting.
Back home, while on Muffs, I manually played with throttle and timing until I found position that motor would start and idle. I found throttle just slightly ahead of carb pickup( a bit high ) and timing at 10-15 BTDC.

1. I'm thinking that my Timing pointer may be off and will need a dial gauge to verify.
   1. If this is the case..then My Max advance would also be set low, but the adjustment screw is already quite low and not sure if I can advance any more.
   2. I also feel that My idle seems to be a bit high and 1 turn to the throttle idle position screw will either stall or Rev really high.

Next week I will take timing light to the lake and see if anything different when under load.

1. Due to stuck/dirty needle valve…I recently replaced the valve seats, valve and floats. I cleaned the carbs(soaked in seafoam followed by compressed air). I also replaced all fuel lines and added inline fuel filter. I believe all fittings are tight but when I squeeze bulb it gets hard but If I continue to apply firm pressure it will slowly squeeze…I do not see/smell any gas not sure where it might be going. I was thinking that an Air leak in fuel line might cause a lean mixture and might the high idle and high throttle position. The Carb idle needle is turned a full 2 turns as it won't start at 1 ¾ but once started I can turn from 1 ½ to 2 ¼ without any noticeable difference to idle speed. It will stall when reduce to 1.

Your thoughts on either of these issues? (related/unrelated) any other ideas

First of all, this is not an auto engine, so ignore the idle speed timing--it's totally irrelevant. All you need to concern yourself with is the WOT timing.

On that pointer setting, you need to find Top Dead Center and align it--I've seen them off by a mile. You find TDC by stopping the top piston (with a stop inserted through the plug hole) from reaching TDC in both directions then split the difference.

Jeff

PS: Removing the top carb's throttle lever (one screw) allows one to hold it wide open at safe rpms.

Thanks Jeff
Picked up a piston stop today. I'll be at lake on weekend and will first set my TDC pointer and then recheck timing positions.
thanks for hint on carb lever...it would be been hard to do timing while bouncing over waves at 30 knots.

any thoughts on high idle and little effect from screws...(needles look in good shape and carbs are clean)
was thinking maybe fuel pump..although if I crank engine without gas tank...the bulb collapses so I'm getting a good suction.

Daniel

On that high idle, too much spark advance. See why you can't turn the distributor further to slow it down.

Jeff

PS: Also check that the carbs are closed at idle.

I had to pick somethin up a cottage so took advantage to go check timing.
I used the piston stop to find initial TDC. then used my digital caliper to find .464" for final adjustment. Pointer was off by about 6 deg ATDC.
I'll spend time on weekend to test it out on the water.
Last week I had to advance the timing in order to get it to start, but could adjust back a bit while it was runnning.

I've double checked and adjusted the throttle lever to be just at carb pickup(may have been ever so slightlystarting to open) and initial timing at around 5deg BTDC...I'll play with throttle position at startup and timing to see if I can find the start +idle spot. I've got the extra lever on my control that gives a liuttle more throttle at startup...maybe use that to start and then set it back down to idle once warmed up.

initially ,I found my throttle arm set way ahead of carb pickup so when I was liftin the lever while starting It was only playing with timing..then when I set it back down, it would retard the timing and the engine woudl often stall if I didn't shift into forward and give thrttle fast enough....all makes sense now

Looks like you're on the right foot. Note that the carbs open WAY later than the timing--I set mine up to achieve nearly full spark advance BEFORE the carbs start to open. That reduces bogging and improves gas mileage. (Sometimes I get a sag when I open the carbs, but never a bog. A sag I can live with!)

Jeff