bought my first boat with 1996 Force 120 and already broke down..... Help please

[JordyOutboard]

Disclaimer: I have never owned a boat before and really don?t know the first thing about them. I do consider myself to be someone mechanically inclined as I do all the work on my vehicles myself. I also have about 14 vintage motorcycles that I perform all the work on as well. If there is a idiots guide to boats that I can read, please point me in the direction. I would like to know the do?s and don?ts of operating a motorboat.

I bought a 1996 Maxum 1700 sr with a 1996 Force 120 outboard two stroke engine. The previous owner was the second owner and seemed to be a very genuine guy. He said he hasn?t had any issues with the boat and it?s ready to go. He takes it out probably 12 times a season with no issues.
So I bought the boat and immediately took it to the water when I got home. I launch the boat without any problems and start her up with the trim completely down. I drove it around for about 30 minutes at various speeds. The 17 foot boat with two adults reached about 34-36mph.
Eventually we found ourselves in some shallower water. I would estimate around 3 feet deep based on how we could see the bottom. At this point we were stopped and to go again I decided to pull the trim up so the props were not as deep into the water. As we started to go the boat started to plane higher than usually based on the trim placement. We drove it for around 5-10 more minutes and then the engine started to bog down to an idle and then shut off completely despite the throttle being open. I did not hear any buzzers or alarms so I am not sure if I over heated it. The engine cover did have some smoke coming from it for a few minutes but nothing other than that. After a few minutes I tried to restart the engine to get us back to the launch but it didn?t go. The battery started to drain at this point. I also noticed that the battery connections were EXTREMELY hot. I am not sure if its because the connections were loose or what.
A nice guy towed us back to the launch and I brought the boat back to the garage for the day. The next day I cranked it over and everything was fine except it didn?t start.

Anyone know where I can start to trouble shoot this thing? I ordered some outboard motor flushers so I can safely attempt to run it while out of the water. They should be here by Wednesday I believe.
I pulled the plugs and they were not completely dry but were not soaking wet wither. I cleaned them off and tried to turn the boat over. It felt like it wanted to start and I also heard a small backfire as well.

Should I start by checking for spark? I am not familiar with these kind of spark plugs. How can I test spark? Ill also do a compression test as well.

Thanks for all your help. I hate that this is my first post but I guess that?s boat life?.

 

[Frank Acampora]

The first basic steps for trouble-shooting are to check the compression ratio, check if spark is present, and check fuel delivery. These three tests will determine further actions.

 

[JordyOutboard]

Thanks for getting me started! I will chck the plugs and compression once I get home. I know the fuel line from the stern to the engine has fuel in it but I will check to see if its getting to the carbs.

Also, I noticed a small oil drip coming out from behind the propeller. I am not sure what the hole is called but I found a similar picture on google and circled where its coming from.


At this point, should I not try and start it anymore?

 

[Frank Acampora]

That is usually unburned oil from combustion and usually normal. Remember that these engines take a 50 to 1 fuel mix OR 1 pint TWC-3 oil for every six gallons of gasoline. The only Force engines to have oil injection (yes, some did have it, a mechanical oil pump driven off the bottom of the crank) were some designed by Mercury for jet drives and branded as other (Sea-Ray etc.)

 

[JordyOutboard]

So I just checked the compression and from top to bottom I got
120
50
130
60

So what am I in for here?? Would this prevent my engine from starting? As mentioned, there was smoke coming from the engine when it shut off on me. I took the cover and noticed a blue and white wire melted slightly on the head(?)

 

[Frank Acampora]

Oh Jeez! I hate when a newbie gets in trouble.

Well, Jordy yes, it could prevent starting.Those compression numbers would indicate possible broken rings on the two low cylinders. Now you need to remove the head and examine the pistons and cylinder walls. Dollars to donuts the top ring on each piston is broken requiring replacement of the pistons MINIMUM. Take a couple of photos of the pistons and cylinder walls so we can help you evaluate the damage.

If you can scrape a fingernail across any scuffing or mild scratches without it catching then you may be able to replace the piston without boring. If the scoring is deep, the a rebuild is necessary.

And to allay any fears: NO, you did not get "taken" Unfortunately these engines do have a habit of breaking the top piston ring and it will run fine until that happens. And, it can happen at any time or never. It is just bad luck.

 

[JordyOutboard]

Update!!!

So I am typing this from my cell phone in the middle of a river waiting for a tow.

How did I get here?
Well I took the spark plugs out again and somehow it sounded like it wanted to start up. This was with the very last spark plug out of the engine and out of the boot. I tried starting it again this time with that plug in the engine agin and it started up with some throttle. After about 3 seconds I shut it off. I hooked up the bot and took it to the nearest launch. It drove fine for about 5-10 minutes and then we by a wake from a passing boat and the engine died again. I removed the cover and the engine was hot again. Like steam was coming off. The boat will not start again and I'm not going to try.

 

[JordyOutboard]

Also, what's the best manual for this engine? Any specific?

 

[64osby]

I would look at finding an OMC manual for the new to you motor you need and will soon buy to replace this motor.

Running outboards hot is like running your jeep without oil. The motor get toasted.

Nice looking XJ by the way.

 

[Frank Acampora]

AHA! Didn't believe me about the broken rings, did you? Just had to try again and got bit in the a**. My Fault! I should have specifically told you not to try and run the engine..

While you may actually decide to buy a different brand engine, they all have their problems and unless you buy new and warrantied, again you will be buying an unknown quantity. So, for the time being, forget the Force bashers and forget about buying an OMC manual.

Clymers is a decent manual and will give you all the info you need to do what is necessary. Of course, the factory manual goes into more depth but it is not absolutely necessary.

SO: Again, first remove the head and check out the pistons and cylinders. Then we can go from there

 

[S.A. Baker]

I feel your pain! bought myself a boat a week ago.....STILL working on it! 42yrs. a motorcycle mechanic.....and this thing is like working on alien spaceships!

 

[JordyOutboard]

I would look at finding an OMC manual for the new to you motor you need and will soon buy to replace this motor.

Running outboards hot is like running your jeep without oil. The motor get toasted.

Nice looking XJ by the way.

SO you think this motor is done for? And thanks. The XJ is a great jeep. Its a 60th anniversary edition. Last year of them.

 

[JordyOutboard]

AHA! Didn't believe me about the broken rings, did you? Just had to try again and got bit in the a**. My Fault! I should have specifically told you not to try and run the engine..

While you may actually decide to buy a different brand engine, they all have their problems and unless you buy new and warrantied, again you will be buying an unknown quantity. So, for the time being, forget the Force bashers and forget about buying an OMC manual.

Clymers is a decent manual and will give you all the info you need to do what is necessary. Of course, the factory manual goes into more depth but it is not absolutely necessary.

SO: Again, first remove the head and check out the pistons and cylinders. Then we can go from there

Live and learn. So you think this motor is still salvageable? Is the rings all it needs? So this would cause the engine to over heat?

I am going to order the manual today. Are any rings ok or should I get a particular brand? I will actually do some research on the forums to see what others used. If I am going to repair this thing, I want to do everything at once.

Thank you all so much for the help. This is a great forum.

 

[Frank Acampora]

These engines are almost always salvageable--the only question is how much time and money will it take. We can not tell until you remove the head and take a couple of good, clear photos of the pistons and cylinders.

Now, if your compression ratios were 20 PSI or less, then it would be an almost certainty that a rebuild is necessary BUT YES, Frequently under these conditions a simple replacement of piston and rings is all that is required and this can be done by removing the carbs and reed plates However, as I said, nothing is certain until you remove the head.

You have more than one problem. The overheating will be caused by a bad water pump impeller that needs replacing. This is simply done by dropping the lower unit and opening the water pump. A new impeller costs about 30 bucks. However, let's not address this until the compression problem is identified and solved.

 

[JordyOutboard]

These engines are almost always salvageable--the only question is how much time and money will it take. We can not tell until you remove the head and take a couple of good, clear photos of the pistons and cylinders.

Now, if your compression ratios were 20 PSI or less, then it would be an almost certainty that a rebuild is necessary BUT YES, Frequently under these conditions a simple replacement of piston and rings is all that is required and this can be done by removing the carbs and reed plates However, as I said, nothing is certain until you remove the head.

You have more than one problem. The overheating will be caused by a bad water pump impeller that needs replacing. This is simply done by dropping the lower unit and opening the water pump. A new impeller costs about 30 bucks. However, let's not address this until the compression problem is identified and solved.

HI Frank,

Thanks for sticking with me on this. I ordered a Clymer manual and it should be here by tomorrow. Ill open up the head and get some good pictures of the head.

As far as the compression goes, as mentioned above, I got readings of 120, 55, 130, 60 the first go around. When I go the motor some what started my numbers were all around 120, 120, 130, 120. What would cause this? Would it be possible that my rings are good and that I just have an over heating issue?

Either way, I am ready to order parts and get this thing fixed. After this obstacle I would like to start exploring other engines to purchase as a back up to this engine. It would be nice to buy something that needs work and have something to learn on as well as a spare engine to keep me in the water!

Thanks guys!

 

[JordyOutboard]

No Title

Some engine pictures

 

[JordyOutboard]

Here is a force 120 tare down video I found on YouTube

http://youtu.be/ZTUH2p8Lf5o

 

[Frank Acampora]

To clarify: Overheating an engine generally will do little damage unless it is overheated to the point where oil burns off the pistons and cylinders and the engine seizes.

with ring breaking: Because only the top piston ring breaks and the bottom ring is usually intact it is possible that with running and some more oil, the compression can come up some

.In view of the great disparity of compression numbers I think it is wise to pull the spark plugs and with a pencil light try to examine the pistons.

Removing the head is not difficult it only has 18 5/16 bolts (with a 1/2 inch head). The head gasket usually will not be destroyed and usually can be re-used. You do need an inch pound torque wrench to install it 225 inch pounds in a spiral pattern from the center outward in several steps. If it were my engine, before anything else I would do a couple more starts on muffs, in the driveway and recheck the compression ratio. If it stays high on all cylinders then yes, your problems may be related to overheating.

If that is the case then it makes sense to replace the water pump impeller and see what happens..

 

[JordyOutboard]

Thanks Frank!

I am going to check compression again today after work just for piece of mind. My muffs that I ordered the past weekend should be here any day now for a more thorough troubleshooting.

Since my engine appears to be overheating and I do not hear any alarms or buzzers, I assume my thermoswitch is broken? If that's the case, I am going to check it out and replace it. It may be smart for me to hook up a temperature gauge as well I guess.

Once my Clymeer manual gets here I will be able to tell what is what on this engine. Because right now, I don't know what anything is hahha.

 

[CApTaInGoOfy]

JordyOutboard I feel for you buddy... Just picked up my 2nd boat, my 1st boat never saw water... Just was a money pit...(1989 Century 3500)
​I am hoping to get my new boat out on the water this week (maybe tomorrow!!)