1973 vs 74-76 Evinrude 135hp piston compatibility?

[73 Rude!]

I'm currently restoring 73' Evinrude V-4 135hp. Does anyone know why the piston called out for the same motor 74'-76' would not work in the 73'? Bore is the same and the wrist pins and rods are all the same. There is much more availability on the later pistons and way cheaper.

 

[Faztbullet]

Wrist pins/rods and crank not the same....different diameters

 

[73 Rude!]

So looking at these numbers AGAIN for the hundredth time. The wrist pins show the same: 0327861. So I don't understand why if I keep my stock crank and rods I can't use the 76 pistons?

 

[racerone]

Many internal parts are unique to 73 V-4 models.

 

[73 Rude!]

Only thing that I can rationalize as an issue would be the width of the rod as it mates to the internal body of the piston. The rods being different they must be a different width on the 73 to the 74-76. Only thing that could make sense? Like I said, the wrist pins show the same PNs between 73 thru 76.

 

[racerone]

Pistons are the same from 74 to 98----The 73 model is NOT included on that list !!

 

[73 Rude!]

You're correct racerone, just trying to understand why and/or whats different on the 73 piston.

 

[racerone]

I used to know exactly but forgot.-----I have more than one 73 V-4 in my inventory.----Some new pistons too I believe.-----Bring over a box of cold ones and we can go over the details.----Measure wristpin position is one place to start I guess.

 

[73 Rude!]

If I were up near Ontario I'd take you up on the cold ones. LOL

 

[73 Rude!]

racerone,

you wouldn't happen to have a starboard exhaust filler block for a 73 in your "inventory" would you? I'm in desperate need of one. This motor that I have now gone from rebuilding to restoring, huge difference, had both blown apart. I found a port but the starboard is very elusive. I have a larger ported one typical of a 140 but I need the smaller ported starboard block to match. Tried to send this to you in a message but not sure you received it.

 

[Faztbullet]

Like I stated different sizes...the 73 piston has a tight/loose side and uses different rod. make sure when replacing filler block that rear deck of block is machine so block and fillers are same height.

 

[racerone]

Where is this motor located ?