Force Gurus Need Your help before I purchase of a 120 HP 1990 parts motor

[weather8]

Force experts I need your help before I purchase a 1990 120 HP motor for parts. From my service manual it appears in 1990 there was an A and a B model motor. The pistons changed size from 3.313 in the A to 3.375 in the B. Is there any other visual difference between the A and the B that I can determine which model motor this is without removing the head and measuring? I am currently working on a 1993 and need a couple of pistons. Trying to avoid having 2 motors both in need of pistons. Thanks for your help

 

[jerryjerry05]

Welcome!!
No if the sticker is missing off the transom clamp.
IF????? you can figure out the boat it came from, you can send the boat maker the hull #
They would probably have the model and serial #

Since it's a part motor take the head off and measure the pistons.

​In most cases the damage to the pistons is usually limited to one, maybe two pistons??

Fill out the profile and signature.
Add the make of the boat, your location.
You might be close to someone who can help?

 

[weather8]

Thanks Jerry: The tag is there,but unreadable according to the owner. The motor is 3 hours away and I was trying not to waste a trip. I appreciate your help and input. I updated my profile Thanks

 

[SkiDad]

Why not just pick up a few Pistons on eBay ?

 

[jerryjerry05]

COST???
​It might be worth it to buy just for the electronics and lower unit?
​If it's a fresh water motor? the parts should sell better.
I always buy if it's in decent shape.
​People on here are always looking for parts(me).
​
I use used pistons if they are in good shape.
Just not the rings.
​FYI: Wiseco rings only fit Wiseco pistons. I found out the hard way

 

[Jiggz]

With the amount of work involved, I highly recommend just getting brand new pistons and even better using Wiseco pistons with the wrist pin kit. Just make sure you open and inspect and measure before buying. Approximate cost is about $100 ~ $120 per piston plus ~$15 for the wrist pint kit.

 

[jerryjerry05]

Usually I agree with Jiggz , not this time.
​Why spend good $$ when the piston you have is still good.
Just get the right rings and reinstall.

Just remember the OEM type piston needs special tools to assemble the piston.

E-bay has all kinds of pistons and rings and they are usually cheaper than buying direct from Wiseco.
They start at 50$ and go up.
​

 

[Jiggz]

"I am currently working on a 1993 and need a couple of pistons."

I probably misread the above quote thinking he needs two new pistons. Sorry.

 

[weather8]

Thanks guys for the information and ideas. I must admit that I am cheap. I would rather pick up a whole parts motor for $200 and try and build 1 good motor out of 2. I look at it like getting free extra ignition,starter, lower unit, carbs etc. The good news is its a B motor and the pistons should fit. I'll know more Sunday when I see it. I will update the post later, since I will surely have a few questions about assembly. Bill

 

[Jiggz]

That is just great! Hopefully, the pistons are still of the same size and not oversized yet. Enjoy!

 

[jerryjerry05]

For 200 bucks!!! I'd buy it just for the other parts.
​The lower unit can get 300$ from someone who's desperate.
Is it a 25 or 20" ?

Sent you a PM.