1976 Mercury 1150 how to set timing and carbs

[Boat4less]

I am having two issue got this boat it ran fine then timing belt broke followed a few guys advice set timing mark like I was told and followed online it will start under a spray of fluid it won't run on its own or idle any one in Texas know how to repair this boat I will pay them or even if some one that can walk me step by step I never had this issue in my life it's older then me but I love the look of the older boats trying to restore it any help would be amazing also lower carb is flowing gas out when prime I assume bad float or stuck so I'm pulling carbs off but my question is what all really needs replacing and what not to unscrew I know it ran good even leaking I don't want mess up the jet settings and idle

 

[Chris1956]

You should get an OEM service Manual. Here is the timing procedure.

First remove the timing belt from the distributor pulley. Spin the pulley and make sure she is not binding. A binding is likely what broke the other belt. Turn flywheel and distributor pulley until cast arrow on distributor pulley points to dot (or three dots) on flywheel timing decal. Install timing belt.

Set idle mixture screw carbs to 1-1/2 turns open, on all three carbs. Remove spark plugs 2-6 and ground wires to block. Put timing light on #1 spark plug. Crank motor and adjust throttle until she reads 4-6* BTDC.

Put 5/16" wrench and loosen two vertical bolts on distributor body. These hold a brass collar. With bolts loose, turn collar until finger just touches carb operating lever. Make sure to take up any play in carb lever, so if distributor moves any more, carbs will start to open. Tighten bolts.

Advance throttle full and crank motor. Loosen or tighten max spark advance set screw (on plate above distributor), until max spark advance is 21*BTDC. Tighten set screw nut.

Install spark plugs and run her on flusher for test. You must launch boat and adjust idle mixture on water, motor warm and in forward gear. Adjust all idle mixture screws to achieve smoothest, fastest idle. Now test motor for acceleration. If she stumbles, open top idle mixture screw 1/8 turn and test acceleration again. Repeat with mid carb idle mixture screw, and finally bottom carb idle mixture screw, testing after each adjustment. Repeat as desired,until idle quality is about 1000 in neutral and reasonable, and motor accelerates smoothly.

 

[racerone]

You might need to remove the plate on top of the distributor to find the arrow.

 

[Boat4less]

Thank you so so much Dose, anyone, have the manual Number i found these two thanks for all your help guy so the cast arrow is to point to the three dots on the flywheel not to the center of the crank ? i followed an online video and it messed me up i think and ill report back after next few weeks i found also the lower carb was full of stuild trash in the float so waitng on gasket set i just cleand the float and soak carbs for a few days in cleaner lower carb was not able to close all way when full

 

[Chris1956]

That OEM Mercury manual looks to be the best bet. Seloc manuals can be full of really inaccurate info.

Yes the cast arrow on the dist. pulley should point to the three dots on the timing decal. Now install the timing belt.

Check your float carefully. The originals were foam and tended to disolve. The newer floats are hard white plastic and can crack. Replace any floats that are questionable.