Distributor replaced, timing help

[79camaro]

I replaced the pickup coil and the rotor on my distributor but like a newbie didn't do a good job marking them so now the timing is out of whack. I've done most everything on my boat and motor from reading the manual and forums, but timing isn't one of them. "rotating the crankshaft until the no. 1 cylinder is ready to fire" aren't things I'm familiar with so I am wondering if someone can walk me through this. I am a DIY enthusiast and willing to learn, but I also don't want to make it worse! This is a 2004 mercruiser 3.0 4/cylinder in a byliner 175. Thanks in advance.

 

[Bt Doctur]

firing order is 1,3,4,2 cylinders numbered 1,2,3,4 remove sparkplug from #1 , rotate motor so your coming up on compression. (finger in sparkplug hole and feel pressure) rotate motor slowly until timing is at "0" . remove dist cap and see where rotor is pointing. Most of us have the rotor pointing toward #1 cylinder ,aligning it with a post on the dist cap and most people don't.
If your a "do" lift dist and align rotor to point to #1 and position dist to a corresponding lug in the cap
If your a "don't" , note position of rotor, call that lug #1, and position plug wires in a clockwise direction 1,3,4,2

 

[MikDee]

Just make sure your crank is on TDC compression stroke for #1, Not crank at TDC #1 exhaust stroke. Being a 4-Cycle engine, each revolution of the crank it will alternate.

 

[Eric 3.7LX Alpha 1]

You can also put a piece of tape on the distributor base, just below the cap. Mark with pen/ marker the exact location of the lobe for the #1 cylinder from the cap. Then when you remove the cap you still have the location of the lobe the rotor has to be pointing at.

 

[saltybutwet]

only a select few Mercruisers 3.0 dizzy rotor points to the about the 4:00 position, at TDCC, from the factory, mine is a 93 year model
see pics

 

[79camaro]

Just make sure your crank is on TDC compression stroke for #1, Not crank at TDC #1 exhaust stroke. Being a 4-Cycle engine, each revolution of the crank it will alternate.

How do i know the difference? I put a plastic stick into the cylinder and cranked the motor until it stuck out as far as I could get it the best I could and put the distributor back on. It started up so I assume it is in correctly? I think the #1 cylinder on this motor is the furthest away from the flywheel?

 

[MikDee]

If you're running fine, you're ok,,, What you look for is compression pressure from #1 cylinder, the 1st cyl. inline (front) of engine.