Installing distributor problems

[JK Turtle]

So over the winter, my manifold cracked, I was able to get it welded back up and have everything installed. When I tried to fire it up, it will try to crank but about every 4 seconds or so it sounds like it backfires and will not start. I have a Mercruiser 4.3 TKS. Unfortunately while putting the engine back together, I left the distributor cap on my bumper and drove off. :mad-new: I ordered a tune up kit that came with a new trigger wheel. So after the engine not starting, I rotated the engine to top dead center, and looked at the trigger wheel and it looks like it about to fire cylinder 3. Now I know I must of messed up somewhere. But, I know when I installed the new trigger wheel, there is only 1 direction it will fit onto the distributor shaft due to the locating key, and I know the distributor shaft will only fit into the engine in 2 directions, but I installed it at the same angle as when I removed it. Even if I did install the shaft wrong, the trigger wheel would be trying to fire cylinder 6. I've double checked the plug wires, and they are all correct, any suggestions?

 

[Bondo]

So over the winter, my manifold cracked, I was able to get it welded back up and have everything installed.

Ayuh,.... Weldin' a cast iron manifold of any sort, rarely works as planned,...
Really not a good idea,... replacement is the proper answer,...

I rotated the engine to top dead center,

On the exhaust stroke, or the compression stroke,..??
The timin' mark goes 'round twice, when #1 fires only once,....

That's my 1st guess on where ya screwed up,...

 

[JK Turtle]

I figured it out. Somehow the oil pump must of gotten turned somehow. I was able to get the engine to top dead center on the compression stroke, lined up the trigger wheel with #1 on the cap, and turned the engine by hand until the distributor lined up with the oil pump and seated completely.