NS90A rebuild

[jjreds]

Re: NS90A rebuild

Getting the parts and service manual was the first thing I did I saw the 50:1 premix and break-in instructions which I will follow. Just the same, I'll make sure the system is primed before I turn it over. Here's the bore and hone job, still waiting for word on the crank. This was the worst one, had zero psi compression, still has a mark in it but not in the compression zone, the others are perfect.

 

[jjreds]

Re: NS90A rebuild

Following up I gave the crank to the tool room here at work to do the press work. I asked them to let me know when they did the work as I wanted to be there. They went ahead without me, and a fixturing error left me with a bent rod. Luckily I found a complete used motor on Craigslist for $450. I tore it down for the crank, and now have a complete set of spares. Here is the block and .030" over pistons:



The used crankshaft with new pistons installed:



Working by myself I had to figure a way to get the crank assy installed into the block, I don't know how the pros do it but I decided to lower it using a sling:



This worked well and I took my time, she dropped right in I used a long skinny screwdriver to move the rings that wanted to hang:



Here's the head all cleaned up:

 

[jjreds]

Re: NS90A rebuild

I used Permatex Moto 1 on the cases and Victor Reinz JV66B Gasket Sealer on the head and exhaust/water jacket gaskets:



After final assembly, remounting the power head and lower unit (resealed w/ new WP thks Paul) I started it up (video follows):



Here's the breakdown for the parts:
$251 Wiseco Pistons
$44 Wrist Pin Bearings
$15 Permatex Moto 1 Gasket Maker
$10 Victor Reinz JV66B Gasket Sealer
$262 PH Gaskets WP kit Upper main bearing
$75 Machine shop bore & hone
$450 Used Motor - free shipping
$115? Lower Unit Seal Kit (didn't write that one down)

Total ~$1,200.00 More than it's worth? Maybe, but I had a hard time finding any decent Tohatsu/Merc/OMC in the 90-100 hp range anywhere near that price, plus I've got a spare starter, stator, oil pump, fuel pump etc. so I feel good about it. Thanks for the help.

Jim