1973 Mercury 1500 (thunderbolt) timing/Distributor Belt Replacement

[Big Tex71]

I have a 1973 Mercury Thunderbolt 1500 (150hp). The timing Belt Broke. I pulled the flywheel (of course i got in a hurry and didn't mark anything) although, it does have the factory timing marks on it.. After thinking about it, the distributor is probably off in magic land anyway, since the belt is broken. I know what i need to do to get the belt on.. but any suggestions on how to re-align the timing. Pull cylinder #1 plug, get it at compression stroke, align TDC at indicator. Then position the rotor at plug wire one as well? reassemble.. it must be an easy task.. cause I can't get it right in my head.. you know.. kinda like my sons 4th grade math..

 

[Chris1956]

Re: 1973 Mercury 1500 (thunderbolt) timing/Distributor Belt Replacement

Easy task. Install the new timing belt, and put it onto the distributor pully anywhere. Now rotate the flywheel, spark plugs out, until a screwdriver in the top sparkplug hole shows that the piston is all the way up. The timing decal on the flywheel should show very close to TDC when compared to the timing mark on the cowling support. If not, the outer flywheel is incorrectly installed, and you must remove the 8 - 5/16" bolts and turn outer flywheel only, until timing marks align. Reinstall bolts with a drop of locktight. Now slip timing belt off distributor pully, and turn distributor pully until cast arrow points to dot on timing decal. Install belt and pully cover and 1/8" bolt with a drop of locktight. You are now ready to perform link and synch

 

[Big Tex71]

Re: 1973 Mercury 1500 (thunderbolt) timing/Distributor Belt Replacement

COOL.. excuse my ignorance... this is my first outboard project.. what does "link and synch" mean? carb adjustments? Also.. the only thing i could find on the distributor pulley is a small "bump" about the size of pin head on the outermost part of the pulley itself, the bottom edge of it? is that the "arrow" your referring too? BTW...I purchased a SELOC manual.. didn't help me with the timing points.. That i could find..at all. SO... THANKS!

 

[monk-monk]

Re: 1973 Mercury 1500 (thunderbolt) timing/Distributor Belt Replacement

Big Tex, do exactly as chris said...get as close to TDC as you can WITHOUT PASSING TDC...now, on the bottom edge of the distributor pulley there is a little NIB...and on the distributor body, just below the pullley, there is another NIB...align the NIB on the pulley with the NIB on the distributor body...now, your timing mark on the flywheel is three DOTS...these three DOTS are cast into the side of the flywheel in a vertical manner...align the DOTS with the cast-in arrow on the flywheel pulley keeping the pulley aligned with that NIB on the distributor base...install the belt, and build up from there...

 

[Big Tex71]

Re: 1973 Mercury 1500 (thunderbolt) timing/Distributor Belt Replacement

right on.. thanks! TGFI=Thank God For the Internet...

 

[Maxz695]

Re: 1973 Mercury 1500 (thunderbolt) timing/Distributor Belt Replacement

Link and sync http://forums.iboats.com/showthread.php?t=168855