1995 Force 120 HP Outboard Powerhead Removal

[95Maxum]

Hello All,

I believe this is my first post on this forum, but I really need someone to help me out. I am still a beginner when it comes to boat ownership, however, I know a little jargon; but please keep it light (or at least be patient, if I ask for a definition). Also, please be gentle as I am inevitably going to ask a dumb question eventually, if not in this post

I have a Maxum 1800XR with a 1995 120 Force Outboard. I have had issues with this boat from day one, in fact, I'll bet I have spent more time out in the driveway working on it or being towed in on it more than I have actually had it on the water. But I digress, I will spare you all the details not pertaining to my question; unless you think it would help to answer the question, if this is the case please feel free to ask.

After battling several issues with this boat (some electrical but mainly starting and running) The last time I had it out, when I tried to start the boat it wouldn't turn the flywheel (unless you count spinning it in 1/4 turn increments) it sounded like a gallop, but wouldn't start. I took it in to my boat mechanic and after looking it over and giving a compression test, he said that one of the cylinders were scored, thus locking up the piston. He advised me not to fix it, but to sell it for whatever I could get out of it with a scored cylinder wall, and buy another boat.

However, I used to work in a machine shop a few years back and know the owner of it quite well. So, I decided to take the power-head off and take it to the machine shop, do the work myself and pay the owner or the use of his equipment. So, I bought a manual for the motor (ordered from this site, if I am not mistaken) and went to work taking off the powerhead.

Sure enough when I removed the head, cylinder #3 (I say three tentatively, it was the third cylinder if you count down from the top) was definitely scored. Everything was going smooth with the breakdown until the end; where you actually take the powerhead off. I should note that I am attempting to take the powerhead off while the motor is still attached to the boat (I don't know if that makes a difference, but I have nowhere to take it off otherwise, because I have to work on it a weekend at a time.)

Anyway, I followed the manual's instructions to a tee (it has proven very helpful) all the way to the last step where it states that I need to remove the bolts that hold the powerhead on. I have removed two, but the manual says there is 6. This is where I have hit a snag. There are 2 torque head bolts threaded upward (perspective is motor upright) from the mount into the block. I can't figure out how to get these bolts out, as they are on the bottom of the powerhead and the space is restricted by the flange that the cowl sits on (best I know how to describe it). It would literally take an Allen wrench shaped like a "J" to get to them. With the limited space even that is debatable. There are 2 more torque head bolts on the outside of the the flange (casing that the cowl sits on; please forgive my stupidity) casing just above what looks like the steering linkage; however, there are two steel (or maybe cast iron) pieces that block these bolts.

Am I after the wrong bolts? I even took off the cover that goes around where the lower unit meets the powerhead and removed those nuts, to no avail.I can't help but think those 4 bolts are what has to come out, but how do I get to them? Is there a trick that I am unaware of? Or am I just stupid? :facepalm: I can't get this to the machine shop unless I get it off, and I would like to rebuild it (if it can be) before summer arrives, because right now all I have is a $4500 Driveway Ornament.

I apologize for the lengthiness of this post, but I could really use some advice. If I am making a boneheaded mistake, please be gentle; like I said earlier I am new. I have heard that the two happiest days of a man's life was the day he bought his boat and the day he sells it. I am starting to believe that. :facepalm: Anyway, thanks in advance for any advice you can give me. I can't really reciprocate boat advice for boat advice, but I can answer computer questions if you have any.

 

[Justinde]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Welcome Rampaging Ray!

I honestly have not had to do the work listed above, but I can say that with the help of this forum, I am cuurently working on my own boat. I found that most marine mechanics/shops will try and sell you a new/newer engine or boat, when you don't need to do so! I have a 1998 125, and I have EVERY confidence that it will give me years of reliable service. I know that you will be able to work on this with the help of the forum, and nut it out!. I know I didn't help with this exact post, but maybe I helped a little with building your confidence in being able to work with this engine- rather than buy a new engine that you need to hook up to a laptop,so that you can work on it.........

 

[jerryjerry05]

Re: 1995 Force 120 HP Outboard Powerhead Removal

You have the machine shop.That's a big problem taken care of.Parts are easy to find.Post a few pics of the bolts/nuts your having trouble with.They make it so easy to understand.J

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

You have the machine shop.That's a big problem taken care of.Parts are easy to find.Post a few pics of the bolts/nuts your having trouble with.They make it so easy to understand.J

Will do Jerry, but it will be most likely after work today 5PM (EST). Yeah, the machine shop is a huge help. I also, have the advantage of being able to work on it myself (I know a boat motor is a different than a car motor, but it's still a motor; so the fundamentals are still there). My thinking is if it can be rebuilt and I can do it for around $600 or less, it will be worth the effort and time. If nothing else, I have learned a lot about my boat throughout this process.

Thanks in advance for any advice you can offer.

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Welcome Rampaging Ray!

I honestly have not had to do the work listed above, but I can say that with the help of this forum, I am cuurently working on my own boat. I found that most marine mechanics/shops will try and sell you a new/newer engine or boat, when you don't need to do so! I have a 1998 125, and I have EVERY confidence that it will give me years of reliable service. I know that you will be able to work on this with the help of the forum, and nut it out!. I know I didn't help with this exact post, but maybe I helped a little with building your confidence in being able to work with this engine- rather than buy a new engine that you need to hook up to a laptop,so that you can work on it.........

That's the thing though, he didn't try to sell me anything; he simply just gave his opinion on what he would do. I actually know the guy pretty well and he runs a very reputable shop. I can certainly see what you are saying though, as I am sure what you stated is par for the course.

Thanks, for the reply. This does indeed seem like a very well organized and knowledgable board.

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

You have the machine shop.That's a big problem taken care of.Parts are easy to find.Post a few pics of the bolts/nuts your having trouble with.They make it so easy to understand.J

Sorry, I am just now getting to this (been a hectic week). Anyway, I have attached the pics.

117.jpg - is a picture of the bolts that are underneath the cowl just above what appears to be the steering linkage. It is positioned to where no matter how long the Allen wrench it forces it to an angle where you can't get a bite on it (there are two of these).

115.jpg - These are the two bolts that are threaded upward (from the perspective f looking down into the cowl). With the cowl in the way there is only about 1/4 inch of wiggle room with your hand down in there, not to mention you have to come at them from upside down.

118.jpg - This is just a pic I threw in that shows the score in the cylinder wall (I mentioned in my initial post that it was cylinder 3, however, I was mistaken it is cylinder 4). I posted this, because maybe somebody could tell from the pic if it was worth rebuilding or if it was shot perhaps.

What do you think? Thanks in advance for all your help with this.

 

[tater76]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Wow, honestly I am running a 55hp with 10 times the scoring your motor has and it still has 120psi on both cylinders. I would get a second opinion if I were you.

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Wow, honestly I am running a 55hp with 10 times the scoring your motor has and it still has 120psi on both cylinders. I would get a second opinion if I were you.

Really???!!? Well that sounds very promising. So, you think that it won't need to be rebuilt? What about the rusting in the cylinder walls, do I need to do something about that? Would be sweet if I could just get some new gaskets and put it back together. Of course, I will get a second opinion from another mechanic first...Do you happen to know of any trustworthy boat mechanics around the Lancaster area or in a surrounding town (Lancaster is about 35 miles south of Lexington)

I don't know enough about boat motors to discern the amount of damage. I know in a car, you don't want any scores, but a car is not a 2-stroke either....LOL!!!!

Thanks for that bit of info, it has definitely piqued my interest. Would still like to now how those dag blasted bolts are supposed to come out though

 

[Frank Acampora]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Let's see: 95 should be Mercury midleg and lower unit. They used a match plate which held the lower cowl on rubber isolation bolts. You need to remove the small bottom cowling around the midleg.--I forget where the bolts are-- Then you reach up through the gap between it and the lower hood cowling and access the bolts--six of em. You unbolt the four rubber cushioned bolts holding the matchplate to the lower hood pan. The whole powerhead and match plate come off as a unit. Then you separate the block from the match plate.

HOWEVER: from what I see in the photo, that cylinder is not badly scored enough to warrant an engine rebuild. It should run quite well.

Before going further you need to check the starter, battery, and cables. Again, before going further, as a confirmation test, try turning the flywheel by hand with the plugs out. It should turn easily with no binding. If you do get binding it may be a broken protruding ring catching in the exhaust port.

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Let's see: 95 should be Mercury midleg and lower unit. They used a match plate which held the lower cowl on rubber isolation bolts. You need to remove the small bottom cowling around the midleg.--I forget where the bolts are-- Then you reach up through the gap between it and the lower hood cowling and access the bolts--six of em. You unbolt the four rubber cushioned bolts holding the matchplate to the lower hood pan. The whole powerhead and match plate come off as a unit. Then you separate the block from the match plate.

HOWEVER: from what I see in the photo, that cylinder is not badly scored enough to warrant an engine rebuild. It should run quite well.

Before going further you need to check the starter, battery, and cables. Again, before going further, as a confirmation test, try turning the flywheel by hand with the plugs out. It should turn easily with no binding. If you do get binding it may be a broken protruding ring catching in the exhaust port.

Well first let me say, thank you for being AWESOME!!!! I really appreciate you sharing your knowledge with me. What you say makes perfect sense.

I have another question. You see I have the powerhead completely taken apart (with the exception of lifting it off the boat that is...) So, I have the flywheel off of the motor and the head taken off as well.

Can I put a towel around the top of the crank shaft and try to turn it with a pipe wrench with the head off and cylinder walls exposed. Or Do I need to put the head and flywheel back on and try to turn it that way?

 

[Frank Acampora]

Re: 1995 Force 120 HP Outboard Powerhead Removal

NO! You use a pipe wrench and I will come out there and beat you. LOL

Since the head is off, there is no compression. Simply slip on the flywheel with the key and turn it. The engine should turn silky smooth. You don't need to put on the nut as you are not going to put any load on and the engine obviously is not going to run.

As far as the scoring, outboards are the same as auto engines: Cylinder walls must be smooth and crosshatched. It is difficult to tell from the photo, but those scratches appear to be only two and they don't appear deep. Additionally, the piston does not appear to be damaged at the scoring. Thus: under running conditions compression should not be too bad and the engine should run fairly well.

Of course, only you can really tell the degree of damage. Since the engine is already partially disassembled, why not get another opinion from the machine shop?

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Thanks again for the info Vice Admiral. Sorry it has taken so long for me to respond, but I just got an oppurtunity to try this out. Good news is the flywheel turns easily. Does this mean I don't need to rebuild the engine? I suppose it was a head gasket? Although, I did notice one thing with the flywheel that I need some clarification on.

When I turn the flywheel it turns very easily for a complete rotation, however, at the start of the next rotation there is just a little resistance for just the first 1/8 to 1/4 turn then it goes back to ease again. I am not sure if this is due to the fact that I just have the flywheel on finger tight and not torqued or maybe because I didn't focus on timing or anything. I just put in on (lined up on the key of course) and snugged it so I could turn it, so it may be because of that. Or it could possibly just be what it does at the start of a new rotation when manually turning it, I don't know.

So, I am asking you, because I certainly don't want to invest the money in new gaskets and time in cleaning it up and putting it back together just to find out that was a problem and has to be disassembled again (that might be enough to make me drive off a cliff...lol). So is that resistance normal or do I need to address it?

Thanks again for your guidance.

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Thanks again for the info Vice Admiral. Sorry it has taken so long for me to respond, but I just got an oppurtunity to try this out. Good news is the flywheel turns easily. Does this mean I don't need to rebuild the engine? I suppose it was a head gasket? Although, I did notice one thing with the flywheel that I need some clarification on.

When I turn the flywheel it turns very easily for a complete rotation, however, at the start of the next rotation there is just a little resistance for just the first 1/8 to 1/4 turn then it goes back to ease again. I am not sure if this is due to the fact that I just have the flywheel on finger tight and not torqued or maybe because I didn't focus on timing or anything. I just put in on (lined up on the key of course) and snugged it so I could turn it, so it may be because of that. Or it could possibly just be what it does at the start of a new rotation when manually turning it, I don't know.

So, I am asking you, because I certainly don't want to invest the money in new gaskets and time in cleaning it up and putting it back together just to find out that was a problem and has to be disassembled again (that might be enough to make me drive off a cliff...lol). So is that resistance normal or do I need to address it?

Thanks again for your guidance.

Just hoping someone could help me out with this.Thanks!!!

 

[Frank Acampora]

Re: 1995 Force 120 HP Outboard Powerhead Removal

In a two cycle engine, if the reeds are still on, the piston compresses the intake air on the downstroke to blow it into the cylinder. It is not a lot of compression but it can be felt as resistance if you are turning the flywheel at a decent speed by hand. You may also hear the reeds "honk" as some air will always bypass them at these low speeds. And because there are four cylinders doing this 90 degrees apart, and because each set of reeds bleeds air differently, you may not be able to feel each piston compressing. It may feel like just one spot.

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

In a two cycle engine, if the reeds are still on, the piston compresses the intake air on the downstroke to blow it into the cylinder. It is not a lot of compression but it can be felt as resistance if you are turning the flywheel at a decent speed by hand. You may also hear the reeds "honk" as some air will always bypass them at these low speeds. And because there are four cylinders doing this 90 degrees apart, and because each set of reeds bleeds air differently, you may not be able to feel each piston compressing. It may feel like just one spot.

Cool, so this sounds like I just need to clean it up and put it back together (replacing the gaskets of course' namely the head gasket) Does this sound about right to you Frank?

Thanks again for you help, you have saved me a lot of stress.

 

[Frank Acampora]

Re: 1995 Force 120 HP Outboard Powerhead Removal

As said before, the scoring in the cylinder looks light and should not cause a running problem. Given this, yes, you should reassemble the engine with at least a new head gasket. Understand however that dignosing by forum is difficult and we may not hit the correct answer quickly. That is why we said to get a second opinion on that cylinder.

To get back to the first mechanic: MANY mechanics will not work on Force engines and MANY people think they are junk. Not understanding the actual cost of repairing a cylinder or not wanting to do the work, he recommended selling the engine without any explanation (as described by you). EVEN IF you needed to rebore that cylinder and replace the piston, if you did the disassembly and reassembly yourself, the actual cost is only a couple of hundred dollars. Where are you going to buy another 120 in good condition for that amount? I would look at that guy's personality and skills in a very jaded manner. Personally, I would not return to him for any repair.

The starter problem is NOT related to compression, but power to the starter. That is why it was recommended to check power to the starter and all connections. A generally poor condition battery or a corroded or loose connection at the battery or elsewhere will cause the slow starter operation and "galloping" you described.

A favorite trick of mine is to use a stainless lock washer on each side of each battery connection. The lock washed is sharp and bites through any corrosion, ensuring a good solid connection.

 

[95Maxum]

Re: 1995 Force 120 HP Outboard Powerhead Removal

Oh, yes I realize that via forum is not an exact science of diagnosing the problem. I think with what I already knew about the engine and your answers to my questions points me in a very solid direction.

Thanks for the advice, I have always thought there was a power issue with the boat anyway, That will be the very next thing I tackle once back together. Thanks again for all of your advice, you have been extremely helpful.