75 115hp inline 6 merc

[jc4thecross]

bought a 115 recently upper end was rebuilt replaced carbs with some bought on eBay cleaned and installed them. all of the adjustment screws were all the way out spark adv. and so on. engine ran smooth and revved nice on muffs. took it out no power to plane out. while on water i turned spark adv. adj. in and found some power. took home and attempted using the guide that clams casino put out, a friend and i set the max spark adv. to 21% btdc adj. carbs went out and what a dog!! i cant wrap my head around the timing dilemma. cars i can do but this is harder.
need a dummies guide for timing procedures. i need some help to simplify the Linc and sync steps. PS hi laddies and tashas dad. JC

 

[Chris1956]

Re: 75 115hp inline 6 merc

Ok Clam's procedure is quite clear. You are just not "lingo" up yet. Remove the spark plugs except for #1, and install them into their wires. Tape them together so all the bases are touching and tape them to the block so they are all grounded. Remove the prop. Loosen the bolts on the brass economizer collar on the distributor, but leave them snug.

First need to set the idle timing pickup to 4-6 degrees BTDC. Attach timing light to #1 spark plug lead. Turn on the key, motor in forward and jumper the starter solenoid to crank the motor. Have someone advance the throttle until the timing reads 4-6 degrees BTDC. Stop cranking and w/o moving throttle, turn the brass economizer collar on the dissy (about 1/2 way up) until the throttle fork just touches the carb arm on the top carb. Tighten the bolts on the brass collar.

Ok, crank the motor again and advance the throttle until the timing reads 21 degrees BTDC. Stop cranking and turn the max spark advance screw in until it touches the distributor body. Tighten the nut.

OK now advance the throttle until the carbs are wide open. Tighten the max throttle screw to just touch the carb arm. Reinstall the plugs and start and warm the motor. Set the idle speed on the muffs to 1000, using the idle stop screw and throttle cable to change it sufficiently, as is necessary.