Static timing 1960 Merc 400 45 hp

[Desert Toad]

Hi gang,

I recently came upon an old HydroCycle (precursor to the jet ski). It has a 1960 Merc 400 40 hp outboard on it that had a broken belt. I've look everywhere trying to figure out what timing marks I should line up with #1 cylinder at TDC. It looks like I have two marks on the flywheel, one that has a 0 on it, and another that I assume is 28-32 BTDC. I need to install the new belt and line one of these marks up with the magneto drive shaft at TDC? but which one? I also assume rotor needs to be pointing to #1 when the belt is installed.

Any help is greatly appreciated!

 

[jimmbo]

This what I found

 

[Desert Toad]

Thanks Jimmbo! I did find the worlds smallest arrow on the magneto, but still nothing on the fly wheel other than The two marks on the top. Perhaps this flywheel is from a different motor? Maybe there is something to show the mark in reference to the key way.

 

[GA_Boater]

It looks like you took the three bolts out that hold the flywheel on the the flange to replace the belt. Shoulda marked the flywheel so it could be slapped back on.

Lift the flywheel off again after setting #1 to TDC. Also take off the timing belt pulley cover.

If it's timed correctly, the arrow on the timing pulley will point directly to the centerline of the crank shaft.

If it's off, slip the belt off the timing pulley and put it back on with the arrow leading or lagging a pulley tooth from the crank centerline. To put the belt back on the crank and timing pulley have to be rotated until the belt slips on.

Rotate the motor until the arrow points to the crank centerline, put the flywheel on the flange and rotate it until the 0 mark is in line with the arrow. Bolt it down and rotate the motor one turn to verify the arrow and timing mark is still lined up before putting timing pulley cover on.

A word of warning - Don't touch the two timing stop screws. A Merc magneto system never goes out of time. The idle screw can be adjusted, but not the other two.

 

[Desert Toad]

Thank you GA! Those bolts were missing when we got this unit, I assumed since it is keyed there would only be one way for the flywheel to be put on the motor. I will go through your steps soon.

Sure glad I found ya’ll here!

 

[Desert Toad]

Okay, with #1 at TDC, the arrow on the magneto lines up with one of the lines on the flywheel, but it isn’t the line that has a 0 stamped into it. I’ve been farming for 25 years and with everything I work on, outboards and two strokes still get me baffled.

 

[racerone]

GA boater ---this flywheel does NOT HAVE a flexplate !

 

[Desert Toad]

No flex plate, no torque converter, or automatic transmission either! . So can anyone tell me if this timing mark is okay, or is something else needed?

 

[Desert Toad]

Those marks were perfect! Too bad I can’t upload a video. I believe this motor was built like the mini hydroplane race motors. Been bored out, bigger carbs, and straight pipes.

thanks guys!