Piston skirts don't clear crank

[udoittwo]

I can't figure this out. I know I make mistakes and that I can deal that and I'm hoping I've done something wrong that is fixable.
I'm assembling the rods to the crank and they won't clear the crank. If I spin the crank, the skirt of the piston hits on the counter weights of the crank. I'm using the original crank and rods, I measured the length of the skirt from the wrist pin to the bottom of the skirt and they are the same as the factory originals. Neither rods nor crank were cut, only polished. The roller bearings are smae diameter as originals.
I know I was in a real hurry to dissasemble it all to get it to the machine shop before they closed but I am fairly comfortable with keeping everything in it's correct place and order. Even IF the rods were on wrong could it make a difference of that much. I could see side to side differences but not length. It looks like I need nearly a 1/8" give or take, more clearence. The overall height of the piston is a little shorter on the new ones but again, the wrist pin to the base of the skirt height is the same.
This is a 1986 75 Mariner 4 cyl. #A199493. If anyone knows Mercury parts, are these the correct pistons "MERCURY 2.875 BORE .5MM PISTON WSM PART No. 100-15-05K"?
It has to be something I missed.
Thanks for any suggestions,
Karl.

 

[racerone]

OK, so is every thing installed in the block ??---Or are you turning the rods on the crank outside of the block.---There might just be a problem with your procedure.

 

[Faztbullet]

Pistons are correct for that model .020 oversize...

 

[udoittwo]

Yes, I am turning the rods when not in block.
This whole way of building a motor is so abstract to me. Honestly, so much of this seems like it could be may a lot easier and to me, this shop manual is so vague. Unfortunatley it covers several models and years. I just can't follow it.
Sunday, I'm going to look at a later model 75 HP. I needed this motor in a month and I am panicking and I'm messing up. Hopefully this other motor will be in good condition and IF I can get it, then I will take my current motor and tear it all back down, take my time, and start from scratch. I haven't done any real damage YET but I am not totally comfortable with what I have done.

 

[Faztbullet]

I think you have pistons reversed and deflectors are hitting in bottom of block.

 

[racerone]

He stated that rods / pistons are not in the block.-----This is the way Mr Kiekheafer chose to manufacture these motors.----Think about it and you will realize that he could have many crank assemlies ready.---With the proper tools this job is rather easy.

 

[quicktach]

1/8" is an awful lot. What exactly did you change ? New parts measure old parts ? New rings - in correctly ? Any sign of anything binding anywhere ? Cylinders true ?

 

[racerone]

When pistons are installed in the block I think everything will turn just fine.

 

[Faztbullet]

then I will take my current motor and tear it all back down,

I assume its assembled in block......