OMC 115 questions all you gurus
 

As yall know I posted before I wanna upgrade the 18 to a V-6. However, that may be changing as basically my uncle has a Wahoo at my house (been storing it there) with a Johnny 115. It runs good but shows it age on the outside. Faded paint/decals. Under the cowling it looks "ok"..no rusted head bolts and such. He rarely uses it. It has sat for about 2 years and he just used it this past weekend and after fresh fuel and filters she ran like a top.

Long story short he is about to get a settlement and buy a new motor for his boat and that leaves me with getting it for little to NO $$. I know the Force 120 has seen better days...runs great but the head bolts and flywheel are so rusted I hate even looking at them for fear they will evaporate.


I dont know the year on the OMC but will look when I get home. Dont know "looper" or not or how to even tell that sorta stuff.

Had my heart set on a V6 but it wont be for a long time and would be dumb to turn this down if it works out. I also know ther're parts readily available should something go wrong with the OMC and my Force isnt worth working on. Even if I could get it apart without breaking every head/water jacket bolt. Some of them dont even have heads left...they are that bad..LOL


So I was wondering:

how do I tell the year?

what else can I look for to help yall ID it?

And whats the most I could take a 115 to HP wise by changing carbs or whatever? Just a 120? 130? or is the 130 and 140 a different/bigger block or something?

Would it be worth it to even fool with the HP aspect of it or just put a fresh coat of paint on, clean her up and fish!?

Need to knwo what year to tell you how high the HP can go. If it's a looper i wouldn't push it any higher than 115HP, if it's a crossflow then it can be taken up to 140HP(but will drink as much as any 150 V -6 out there can). loo kat teh cylinder heads, if they are rounded without removeable head covers it's a looper, if it has a bunch of bolts on the cylinder heads with removeable covers it is a crossflow. Also teh looper will ahve a 1 piece block whereas the crossflow will have a removeable chest between the heads for teh exhaust cavity and it will also have covers on the outside of the block over the cylinders for the intake ports. If it's a looper I would jump on it as they are great engines and the 60 degree loopers were some of the most reliable outboards ever built. Crossflow engines are good engines, but tend to be thirtsy. they are reliable and simple though with ALOT of parts out there for them cheap. Also they are lightweight for there HP. Look on the port side clamp bracket and see if you can find a serial number on it that ends in 4 letters.

Stink there is or should be a tag on that engine somewhere, my 96 115 had it on the part that bolts to your transom right below where the trim pump sat.
I love those engines man, I had two and both were potent, the last one i had is what powered Old School. That puppy sat on a bracket but it pushed her to 36 mph loaded.
Clean her up, make her look pretty if you want but I would not let her go and I would not mess with the HP. She has a lot of dog in the hunt already, trust me.

Thanks guys..going home shortly and will look and take pics!

Oh I forgot, they sip gas, after having my 150 and being used to that I actually thought my 115 was producing fuel instead of burning it

That would be a NICE change...that damn FORCE is HORRIBLE. Just with a moderate load and two people I struggle to get 2mpg. Although I know its a heavy lil boat too.

Upon closer inspection its a crossflow from what you said Ferm. But more importantly not it quite the shape I though it was in. Rust on a couple head bolts but the steering armiture is pretty rough too. Does it look like it can be changed?

http://img.photobucket.com/albums/v7...g/IMAG0445.jpg


http://img.photobucket.com/albums/v7...g/IMAG0446.jpg


http://img.photobucket.com/albums/v7...g/IMAG0447.jpg


http://img.photobucket.com/albums/v7...g/IMAG0448.jpg


http://img.photobucket.com/albums/v7...g/IMAG0450.jpg


http://img.photobucket.com/albums/v7...g/IMAG0451.jpg

Also there is NO plate...Im guessing it was lost of rusted of at some point between crappy paint jobs. So I dont know the year?


Oh and its a 25" shaft so i would need to find a new mid or raise my transom...I kinda like the idea of raising my transom..

that engine appears to be a late 80's 115 and already has the bubble back high flow exhaust on it. The rust on it isn't that bad compared to many of that age, and it looks like a good pressure washing then some wire brushing followed up by some OSPHO and good primer and paint would take care of the steering arm for a long time. It's a good solid engine, but not by any means easy on fuel for that crossflow. That's the same basic engine that my had(1.6l SEA-DRIVE was a 115 JOHNSON), and that thing drank gas like a V-10 DODGE truck towing 20K pounds. It used 12 GPH at a 3800RPM cruise I figured. On a lighter boat though many say they aren't that bad.

Thanks so much for the help Ferm. Gonna wait on his settlement and see how it pans out.


Do you think I could pull the arm off? Just the two bolts and its free?

Negative, getting that steering arm off is a job and a half. Basically you have to strip the majority of the engine down. Removing the powerhead is adviseable, but at the minumum you have to pull the lower unit. Remove the 4 bolts that hold the lower mounts to the lower pivot arm. Then pull the upper 2 bolts out and remove the engine from the clamp bracket assembly. Then you get the fun task of removing the large nut from the steering arm and getting that lower bracket off and then slide the whole steering shaft out from the clamp bracket. I would just clean it up, OSPHO it, then prime and paint it.

what is ospho?

Phosphouric acid. it converts rust into black iron ferrite which kills rust.

http://www.ospho.com/

Stink, look on the left hand side of the motor on the top about 5" above the spark plug for one of these.
The first row of numbers is the model, year, etc. The next row is the serial #.
This is a 90 horse.
http://i175.photobucket.com/albums/w...shplug90hp.jpg

Oh, post that first row of numbers and letters. We should be able to tell most of the stuff about that motor, at least the year.

OK, Ill check again, thanks

Also consider this thing if you ain't real sure about wanting to tackle the transom yet.
http://www.boatownersworld.com/thmar...king_plate.htm
That was on the first site that popped up.
Different places have them at different prices, just gotta watch how much the "lower priced guys" want to charge for shipping.

Here we go



http://img.photobucket.com/albums/v7...g/IMAG0542.jpg

So is this really an 85 horse with a 115 cowling or 85 model?

It's eaither a late 80's to early 90's engine, or a factory remanufactured powerhead. Aroundd 87 or 88 OMC didn't stamp all of the powerhead welch plugs with the correct info for all of them, and reman powerheads came with a number like this as well.

Stink, I'm at a loss there. That don't appear original from what I'm used to seeing.
I hope FERM sees this and can enlighten us.
My best guess is the powerhead is not the original one and that is a part number.
The 85-140 horse take the same block, I'm guessing the "85" portion is just the 4 cylinder designation not 85 horse, the "R" is for remanufactured and the rest might be the serial number.

FERM, I was slow posting.
Are any of my thoughts possible?

Have I stumped THE FERM?!?! :hide:

not really, I just don't have the books to decipher that code(I've yet to find a dealer that has it either). I would say it's a really late 80's 115HP engine. It has the bubble back exhaust on it which would make it either an earlier 135-140HP powerhead rated engine, or a mid to late 80's propshaft rated 115HP. I believe the later 15's came with the 140 porting, bubbleback exhaust, and other goodies, but had teh smaller 115 carbs to help keep fuel gulping down a little. Only way to know for sure is o pull the airbox and measure the throats of the carbs(I believe they should be 1 5/16", earlier 140's had 1 3/8" carbs). It's the same basic engine as the 85, but the bubble back exhaust flows quite a bit better and the 110+ had slightly differrent porting to them for the extra HP.

:clap: