Force 120 identification

[Kiwikeith]

Hi all
I'm looking to repair/ rebuild my Force 120 1995? problem is the tag is gone and I don't know the model number.
Is there any way to positively I.D my motor from engine or otherwise. There is a number cast into the block that looks like 800-818154-C5 beside Made In The USA and there is a circle with the letter C in it, if that's any help. Is there identifying parts like ignition or starter etc
Was there different models produced in 1995?
Also can anyone tell me the compression figures please.
Thanks in advance.

 

[jerryjerry05]

The comp on some 120's was something like 145 on #1 and 4
And 155 on 2-3.
​Or maybe it's the other way(getting old)around.

​Any way: with a good gauge the readings should be all within 5-10# of each other.
​My 1988/85's If the comp is anymore than 5# difference it starts to start hard.

​Mercury bought Force and started putting their parts on the Force motors about 1993/4
​That motor might have a silver plug cast into the block somewhere.
​The plug will have an ID# scribed into it.
​It should start with an OE000000 and have 6 numbers behind the OE.
​Look for that.
You can add pics after 5 posts.

Oh yea Welcome!!

Fill out the signature and add a location.

 

[Fun Times]

The comp on some 120's was something like 145 on #1 and 4
And 155 on 2-3.
​Or maybe it's the other way(getting old)around..

I just happen to run-across Forces Compression Tests Numbers - 120 HP Which reads:

Models Affected
1995 - 1996 120 HP SPORT JET MODELS
Serial Number 0E093700 and Higher
1995 - 1996 120 HP FORCE OUTBOARDS
Serial Number 0E093939 and Higher
The first production 1995 models of the 120 Sport Jet and Force 120 HP outboards had a cylinder head change. This was the result of a slight modification to the piston dome. The compression readings will now be different between the cylinders. The average compression readings with a cold engine are:
#1 Cylinder (Top) 135 PSI (931 kPa)
#2 Cylinder 150 PSI (1034 kPa)
#3 Cylinder 150 PSI (1034 kPa)
#4 Cylinder (Bottom) 145 PSI (1000 kPa)
Cylinders #1 and #4 were lowered to prevent any tendency to detonate.
This method is not new. The Force 90 HP has had the same compression as the top three cylinders shown above since the 1990 model year. The Sport Jet 90 has had the same compression as the top three cylinders shown above since the 1993 model year
Please note these compression readings in your Sport Jet Service Manual (90-831996), the Force Outboard Service Manual (90-832749) and the Force Technician?s Handbook - 1995 and 1996.

 

[roscoe]

Welcome to iboats.

By 1995, the 120 pretty much just came in one configuration.
Any serial number or model number differences were just to document production runs and parts suppliers.

Model years 91-92-93 and the first half of 1994 did see a lot of changes.
1997 switched to a different ignition system.


Depending on the condition of your engine, you may also find some small white paper stickers on the starter, or the ignition components, that may contain the year of manufacture.

If you can post a link to your photos showing us the fuel pump, and the ignition board components, we could narrow it down for you.

 

[jerryjerry05]

Mecury used their ignition as early as 91-92
​Like Roscoe said pictures can tell us a lot?
Lots of pics??

 

[Kiwikeith]

Thanks jerryjerry05, I can't find a scribed plug anywhere on the motor.
The compression figures I got are very low compared to what you stated. Might be time for some work on the old girl.
​Cheers

 

[Kiwikeith]

Oh and how do I add signature and location (NZ)

 

[Kiwikeith]

Thanks Roscoe, there is a sticker on the starter but all I can read of it is possibly "18" under the barcode. There are a lot of symbols and numbers stamped into the block and various place but none starting with OE...... as mentioned by jerryjerry05.
Cheers

 

[Kiwikeith]

Thank you Fun Times

 

[Fun Times]

Oh and how do I add signature and location (NZ)

The following link should help guide you with adding all your recommended info, http://forums.iboats.com/forum/other...nature-picture :encouragement:

Thank you Fun Times

:thumb:

https://www.perfprotech.com/blog/ma...ry-marine-outboard-motor-serial-number-number

 

[jerryjerry05]

IF?? the comp #s are low??
You remove all the plugs when testing ?
​If they are ALL low?? then use a different gauge.

​Low on 1 cyl? then maybe some work??

 

[Kiwikeith]

Hi jerryjerry05
Compression numbers were 1-100 2-125 3-130 4-120.
Pulled head of and #1 cylinder has visible scoring, removed intake port and can see corresponding marking on the piston. Rebore?
All other cylinders look to be in very good condition, hone and new rings?
I have added a link to some photos to hopefully help with I.D. The photo close up of the block has a number that looks like 900-817609, any help?

https://goo.gl/photos/iRmQXdiRkUoTRSN86

Thanks again for your help

 

[roscoe]

Looks like it is probably a 1995 model.
Switchbox ignition, conventional coils, square fuel pump, etc.
Might be a '94, but makes no difference for parts.

What caused the scoring?
A broken ring?

Hone or bore depends on depth of scoring.
You can just bore the one damaged cylinder and replace with oversized piston if needed.

 

[jerryjerry05]

Like Roscoe said, if there is damage on 1 cyl. just redo that cyl.
The best thing is to break it down and take to a machine shop.
​They'll be able to tell you how much it needs to be bored out.
​Most time it's about .020 over.
​The parts are readily available and it's not that hard of a job.
​Replacing one oversized piston isn't a problem.
I rebuilt one 4-5 years ago and its still running.

​The piston replacement will be easy as the wristpin is held in by clips and disassembly is easy.
Wiseco sells a good replacement.

There are some parts places that might have some of the stuff you need.
​Gotta look around.
This site sells stuff but I'm not sure if they'd have the right stuff???

If your gonna rebuild?? I'd start another thread and document it with LOTSSSSS of pics.

That 900# is a casting #
Under the electronics on the top cyl. might be another foundry mark.
It might have the year in the center of the mark.

The name kiwikeith means your in Australia??
​Parts are gonna be harder to get but not impossible.
E-bay is a good place to look.

 

[Kiwikeith]

Thanks for the info Roscoe.
Not sure yet what has caused the scoring. Will have to delve deeper and check everything as I go.

Thank you too jerryjerry05, you're close about being from Australia, but I'm from another South Pacific paradise called New Zealand.
Parts availability does look to be ok from what I've seen with most suppliers shipping internationally. Only have the exchange rate to worry about now and import tax.
Once again thanks for everyone's help so far.