1995 Force 120 HP rebuild

Force outboard 120HP SN:OE102939
Hi forum, well I am the new guy and I need help rebuilding my powerhead, please. The powerhead broke a conrod and damaged the crankshaft over a long period. I bought the boat 2 years ago, always had minor issues, not starting, bad idle....so after 2 years and about 15 hours it stopped completely. I took the head off and to no surprise I could see why I always had issues, not me the engine.
I disassemble the the powerhead to look for more damage then found the broken conrod, needless to say I could not even find the conrod bearing, the only evidence I could found were some nuggets on top of the piston. Now I need parts. Being in New Zealand does not make things easier so I would have to get all the parts from the US, therefore I need to find the correct part numbers.

I think I've got most of the numbers sorted. The only one I struggle with is the crankshaft(13 tooth spline). According to the boats.net website I need a 820319A. The number stamped on the crankshaft i removed is 817400 which is the number for a 1994 model. The conrod, piston(bottom guide)3.375', wristpin 17.5mm and crankshaft bearings are all the same for a 1994/1995 model.

Now the million dollar ? Would it matter if I use anyone of these? Photo's avail if needed
I thank everyone in advance for your input.

I believe you are going to waste time and money.---------Find something better to rebuild.

You might be right racerone, but it still my best option.

I didn't see any pics?
But from the sounds of things it's an anchor.

You look on e-bay?
Try a Google search:

http://boatpartsferret.com/ Here's a multi listing company.

Hi, I still need an answer on the difference between the crankshafts, please. To you I might be wasting my time, but to me its the difference between a rebuild ($3000) and a secondhand replacement($8000).

The parts are all available, I just need to know which crankshaft to buy.

I hope that there is someone who can help with a constructive answer.

Here is some pics of the damage

"Now the million dollar ? Would it matter if I use anyone of these? Photo's avail if needed
I thank everyone in advance for your input. "
Use anyone of what?

The crank for the 95 is specific to that year.

Look on the top of the powerhead under the coils and packs.
There is a foundry stamp.
It will have the year it's made in the center of the stamp.

If you have a crank from 94 it's probably a year older than you think.
Post that and I can search further.

Try over on i boats too.
There is a bunch of good Force guys there.

Hi,
''Use anyone of what?'' Crankshafts. The cowl, drive shaft housing and lower unit are definitely that of a 1995. Would it be possible that they used a 1994 power head? I don't have the power head with me at the moment, but will check the foundry stamp.

Hi everyone,

Sorry for the delay, Now that I have identified it as a 1995 model with a 13 spline crankshaft I am ready to go ahead and research all the parts. I could not see a foundry stamp on the block I have found most of the parts by now(even a good secondhand crankshaft) and the block is in for machining and I have decided to go 0.030' oversize on the pistons. It will be a slow and thought trough process that will be my winter project. I would welcome any suggestions and ideas from the forum and keep you all updated as I go.

I agree with racer one. I was going to rebuild, found a good powerhead (150 comp on all four) on ebay for 500 bucks delivered to my door. Put my bolt on stuff on it, running like a champ now for 4 years. Mine was from a water rescue boat in the Great Lakes area. Very low hours, fresh water. You CAN find one, as it seems a lot of people part out these old force motors because they can make more money that way than selling them in one piece. Mine came with no flywheel, electronics, anything that bolted on. It DID come with the intake manifold attached. Good Luck!

I hate to sound negative too, but I just finished rebuilding a Yamaha 50HP 1999 that didn't have anything too much wrong with it and I ended up spending about $2000 just because the more you look the more you find and there is no better time to replace a part while it is apart. Was it worth it in the end? Probably not. I certainly had a lot of fun and learned a hell of a lot, but it probably wasn't the best financial decision I could have made. I could have sold the parts that were good and put them towards something running. Anyway, just something to think about before you commit because there will be unexpected expenses along the way and outboard parts are never cheap! I do wish you luck though, I made lots of vids on my rebuild which I hope can help other people giving it a shot.

Stuart

Racerone might be right if you can find a cheap powerhead, but not if you have to buy a whole second hand outboard. Living in NZ does have its limits. Parts are very difficult to find. Its cheaper to buy in the US and ship it to NZ. So yes I agree if you CAN find a powerhead that cheap rather go for that option or else you need to buy parts. Cost so far around US$900 still need center main bearings and a gasket set.

I finished the rebuild and the motor runs very well and a lot more responsive, no more starting issues and a least I have piece of mind knowing that the motor will last some time. Overall I end up spending about 3000NZD. It was definitely worth it and I learned a lot.
ps. Dangarstu watched some of your videos, really good, thanks for the advise

OHNO said:

I finished the rebuild and the motor runs very well and a lot more responsive, no more starting issues and a least I have piece of mind knowing that the motor will last some time. Overall I end up spending about 3000NZD. It was definitely worth it and I learned a lot.
ps. Dangarstu watched some of your videos, really good, thanks for the advise

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I'm new to this forum as well and I'm about to tackle this same rebuild I was curious if you took any pictures or have any advice for someone about to rebuild a 95 force 120? Any advice and or pictures of your rebuild (or anyone's rebuild at that) would be very much appreciated! Thanks in advance.
My situation:

I have a 95 force 120 that has been in the family since new.
Top cylinder failed.
Lower unit blew out due to a freezing winter (must of had water in lower unit)
I purchased a 96 force 120 for $300usd (Need a lower unit but everything else in good condition)

Always start your own thread.

The 95 and 96 lots of parts are usable.
The block does it have good compression?
You might just be able to swap powerheads??
If possible always include the model/serial #s
Makes for easier ID

b.lite said:

I'm new to this forum as well and I'm about to tackle this same rebuild I was curious if you took any pictures or have any advice for someone about to rebuild a 95 force 120? Any advice and or pictures of your rebuild (or anyone's rebuild at that) would be very much appreciated! Thanks in advance.
My situation:

I have a 95 force 120 that has been in the family since new.
Top cylinder failed.
Lower unit blew out due to a freezing winter (must of had water in lower unit)
I purchased a 96 force 120 for $300usd (Need a lower unit but everything else in good condition)

Click to expand...

Hi, you will enjoy the challenge. I bought all my parts from http://shop.tsmperformance.net and a few secondhand. I've attach a few pic's