1984 Mercury Tower of Power Inline 6 Compression and power

[frankrizzo]

I have been having trouble with my 1984 Mercury on my 21 VIP center console the most I can normally get out of it is about 15mph today I installed new switch boxes, i have a new stator and new wires. With a DVA adapter I get 185 volts going to each coil. I did a compression test today and only have 65lbs of compression on each cylinder. Could this be the problem or should i keep trouble shooting. I have rebuilt all of my carbs so i dont believe it is a fuel problem.

 

[Chris1956]

If your cylinders have even compression, the compression is fine, and the gauge is faulty. There would be almost no way all the cylinders would be even in compression, at 65PSI. Has the motor ever exceeded 15MPH? What king of prop pitch are you running? Does the motor die as you push the throttle forward. With the wrap cowling removed, do the carbs open all the way, as you advance the throttle? Did you set the timing, when you changed the stator?

 

[frankrizzo]

How do you set the timing? I just made sure i bolted everything back on exactly as it was initially. I misplaced my service manual, I will have to order another online.

 

[Chris1956]

Well, the timing is easy to check. Remove spark plugs 2-6, install them into their wires and ground them to the block. Now advance throttle to full, put a timing light on #1 cylinder, remove the prop and crank the motor, by jumpering the starter solenoid (ign on). Max Spark advance should be 21* BTDC. Now cut throttle back until carbs are just about to open (idle pickup timing). Crank motor and see if idle pickup timing is about 4* ATDC.

Setting the timing is a little more tricky. You might wait until your manual arrives.