1976 Merc 1500 - Post Carb Rebuild, Rewire Video

[Kargh]

Hello!

Before I go much further with this motor or throw it in the water to adjust the carbs, I'd like it if those of you with far more knowledge and expertise than I would take an eyeball at my video and tell me if you see anything that stands out that might need to be changed, tweaked, fixed, etc. More specifically, if something should or should not be happening. To me it seems to be running fine but with no other experience with these motors, fine is very relative.

It started right up, no issues. Primed bulb, choked for a 15 count, turned key and it fired in about 5 seconds. Didn't even touch the fast idle lever.

RPM gauge indicated it was running around 500-600 for a while then as it got warm, it climbed up to about 2500. That was just sitting in neutral and with muffs. I did, at one point, lift the fast idle lever to verify it would work, and the sucker took off like a bat out of hell.

I have not done a link-n-sync yet. In fact, having been unfamiliar with it, I just started reading about the procedure today. No timing light but I did find the Youtube video by cturboaddict that others have posted in the past. doesn't seem overly complicated though I do have to figure out how to get to TDC first (apparently).

Any thoughts are always appreciated!

https://youtu.be/n_xFQMVFv70

 

[Chris1956]

OK, You have a high performance motor there. You must set timing correctly or she will blow. You will need a timing light, and some way to accurately measure distance from top of piston to head. I used a caliper, but a fine ruler would work. Right now it sounds like the link and synch is incorrect, as motor should not change speed, as you have cited.

Remove all spark plugs and prop.

Use the ruler to set #1 piston to top dead center. Measure to top of piston. Turn flywheel CCW until piston drops ,464 inches. Set timing pointer to point to .464" on timing decal. Now advance throttle until carbs are ready to open. Install #1 spark plug only. Install spark plugs into their wires and tape their bases together and ground their bases to the block.

Crank motor and read timing. It should be 4-6* BTDC. There are two small bolts under the brass collar on the distributor. Loosen those and adjust the brass collar to make the timing correct. You want the carbs to open as timing hits 4-6*BTDC.

Now open throttle fully and crank motor, by jumpering starter solenoid. Adjust max spark advance set screw to read 21*BTDC. Adjust throttle stop screw to allow the carbs to open fully, just as they hit the stop.

Install the spark plugs and adjust the throttle cable and idle stop screw to allow the motor to idle at 900 or less in neutral, on the flusher.

 

[Kargh]

I'm going to have to eyeball the tach as I don't think it is actually working. I was just watching it and it slowly rises regardless what I do. I can start the motor, RPMs will be at 400, lift the fast idle lever, RPMs will be at 400, maybe 500 depending how long it took me... eventually RPMs will be at 6, 7, 1000, 1500, 2000... just idling. Shut it off and start it again, and the gauge will do the same thing.

 

[Kargh]

So I did the adjustments for the link and sync... seems they were pretty much set where they should have been.. except for max advance... I now have that set as well.

 

[Kargh]

Post adjustment video: https://www.youtube.com/watch?v=Ik-6cUx1wXo