Timing on 351 Ford Mercruiser help please

[Brock.Ward]

I have read everywhere that TDC is 10 Degrees BTDC and A. My question is when I set my timing at 10 degrees after 0 and turn my distributor to point 1 my number one plug is at 3 oclock. I have seen pictures and many other orders on the web and this is nothing close to those, last guy had his first plug at 7pm. Should my TDC be at 10? Does it matter where my 1 lines up? I just got this boat and the distributor was loose and cap was off, no idea how the timing should be set at these. # timing for dummies.

Also i have read firing order is 1-3-7-2-6-5-4-8? This is a 1975 slickcraft 233 hp ford mercruiser
Pics and help would be appreciated! Thanks much!

 

[Walt T]

You can set the number one plug wire to any tower you like. The rotor certainly doesn't care. Just keep the firing order correct and rotation direction correct. Sometimes you have to move everything a tower over to be able to set distributor wherever you need to. Sometimes you have to pull the distributor and re insert it to get it in the right position. The illustrations don't mean anything.

You have the right firing order.

 

[Brock.Ward]

Thanks, I did that, I turned the rotor while in the engine so that 1 is lined up with the rotor at Ahead 10 degrees on timing mark. Still no start. Does that sound right? I read its supposed to be Behind 0 at the 10 mark.....

 

[haulnazz15]

Dont turn the rotor anywhere. Find TDC on Cylinder #1 (make sure it's the compression stroke, not the intake stroke). Wherever the rotor is, it is. Don't turn the distributor anywhere. Install the distributor cap with one of the posts set on the same position as the rotor, note that post as cylinder #1. Install the rest of the plug wires in the proper order counter-clockwise around the distributor cap. The engine should be able to start in that condition, assuming you are getting spark/air/fuel. The distributor can then be rotated in conjunction with a timing light to get it to 10BTDC on the harmonic balancer.