OMC 120 1982 last of the stringers it seems.

[Alexo1us]

Before anyone asks it was a gift. But I love the boat 19' Renken BR. anyway my buddy (I'll call him Gilligan) gave this boat after he bought a new used one. He used it last year but it over heats under power run all day under 1500RPM but runs up the temp very fast. After wearing out the gears for a second time he discovered he didn't need to put it out but an inch this solved the over heating problem. Now me being more Mechanically inclined and now it is mine want to fix it correctly unless it will be just too much I could repower with a Merc (These things I know) for about 2000.00 I want to restore her to her former glory and this included the OMC so I want to keep it.<br />My questions <br />1 I wonder if there is something that all the Mechanics that looked at missed like holes just a little out of alignment I do not have a manual yet and I know they have some weird path for the cooling water to travel. For me if the engine will cool just slightly lifted must be something I could do to fix this correctly. But if this is something that will require a Major replacement. I might just as well try to use it as much as I can, and repower in the fall. Then I will be asking for suggestions on the best way to fill the hole. <br /><br />2 The other option My buddies Idea is to put some stops in the pin guides to hold it out the correct amount that allows it to run cool But I worry about the new gears I need to install. Would even this short distance be too much for them? <br />Work done last year<br />2 new sets of finger gears<br />Impeller and housing<br />Engine was rebuilt the year before.<br /><br />All in all a very good strong boat no rot few dings in the fiberglass that I will need to address in the fall but nothing other then the over heat thing to keep me out of the water this year. <br /> Thanx in advance <br />Alex<br />

 

[Boatist]

Re: OMC 120 1982 last of the stringers it seems.

Alex<br />To start with I dout you can repower for $2000. In the USA most say cost is $10,000.00. You first have to pull outdrive and engine and rebuild a new transom. Cut out new holes for the new outdrive. Make new motor mounts. Change everything from the motor back. That a lot of time and a lot of work. New parts alone will be at least $4.000.00<br /><br />Your problem of over heating with the motor down in the run postion I have not seen before. Only thing that makes since here would be if the outdrive itself is plugged up. Tilt the motor all the way up, pull the prop, put the hose in behind the prop area and stuff some rags around it, Hold it there and have someone turn the water on to back flush the outdrive. Watch and see what comes out.<br /><br />Most of the time when I have seen over heating at high speeds the problem has turned out to be water blockage between the exhaust manifold and the riser. Rust and scale will plug up the holes there and not allow enough water to get thru to cool the engine at higher speeds.<br /><br />Nothing tricky about water passage on this motor / I/O. The outdrive water pump pumps water up to the engine thru a hose on the starboard side of engine. Hose connects to the thermostat houseing. water flows acrossed the thermostat to the exhaust manifold, thru the exhaust manifold out to the riser then down and out the exhaust passage and out thru the prop. Engine water pump sucks water in thru a hole near the thermostat houseing. When the engine reaches normal temperature the thermostat opens and allow hot water to flow out. The hot water is replaced by cold water sucked in by the engine water pump.<br /><br />Engine should not be run above idle with the engine tilted at all. Many reasons for this, to start with you will wear out your ball gears. Also the guide pins that hold the engine straight and locked will not be engagued

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

I know about the work I have done it well not a repower but I have installed from new Mercs even cut the hole. Personally if I get the OMC to where I could be sure it runs and gets me back with out any problems. I would like to keep her in As I said before I would rather get it right then running on a work around since the work around would mean repowering in the fall. When I said 2000.00 this only was the cost of the replacing it with merc no labor. I know I can't get a newer unit but I can get a whole boat with an I/O for that boats are pretty much shot but the drives usually run good and for me since I can pretty much see the Mercs in my minds this would be what I put in. I haven't really had a good look yet but going to tonight and take some pics for the album you know before and after.<br /><br />Thanks for the advice on where to start I was a little over whelmed by all the bad rap the OMC gets. But I thinking now since you suggest pretty much the same sort of things that go wrong in the Mercs, maybe once I get a good look I will solve it the correct way.<br /><br />Sorry for the quick response it may be hard to read but lights fading must go.<br />I want to try your suggestions this is my first boat in years and now I'm looking forward to it.<br />Big hole in water for money it is.

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

Ok I did what suggested with the back flush but it came out at the joint between the lower gear case and upper case should there be a gasket. It doesn’t look like it, besides the hole in the front of the upper case would allow it to flow out but I can't see how much father up anyway. . Took it off. Couldn’t real see where there would be a block. <br /><br />Side covers (Pivots) are not in good shape the one side has one bolt missing since the hole got striped the other has had all the bolts replace with incorrect ones I can't help but feel some how the problem is here. Looking at the path and discoloration there seems to be a weeping. One thing that was said was one side of the exhaust riser is very hot and the other is cold. But if it were a blockage how would it pass enough water to keep it cool when tilted out slightly. <br /><br />I need to find a manual; I want to fix the sides covers. How important is the sealing here? I guess I start here and keep going until I find the problem. <br /><br />Any thoughts would be appreciated<br /><br />Alex<br />

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

So the story continues today I spent the morning hunting down the service manual, found one. And the things I learned like there should be a law against guys working on something and not having a clue. Anyway this is why they make manuals to help find the correct way to put things back when you take them apart. Aside from the obvious damaged cap screws I need to repair I found that the pivot caps were incorrectly installed the metal plates were also installed upside down.<br />The bearings on the pins also have a specific way of being installed and they to were off just about an inch. Could this be the reason it would cool fine tilted out an inch. Since by the time I had it all back together it was late, so the water trial will have to wait until tomorrow. I hope I have found the problem. All in all in looking over the manual. I have come to the conclusion that the OMC is not as bad as they are made out to be.<br /><br />Thanx for the help anymore thoughts would be appreciated <br /><br />Alex

 

[Boatist]

Re: OMC 120 1982 last of the stringers it seems.

Alex<br />I think you are on the right track. Very glad to hear you got a manual. Like I said before I have never seen one that only overheated when outdrive is all the way down. Water from your outdrive water pump does go thru the pivot pin on the starboard side. Also on the starboard side pivot pin area you should have a stream of water spraying on the ball gears. If it still overheats when you take it out I would suggest you pull the hose that runs up to the thermostat houseing. Direct it over the side or into a bucket and start the engine. You should have a good stream of water there if the outdrive water pump is good and water is getting thru the pivot pin assy. Note the starboard pivot pin end cap has a option to add a different cap that has a water flush inlet so you do not have to use the muffs. If that pivot pin bearing and end cap were not on right you may not have been getting any cooling water to the engine. <br /><br />As Far a OMC being a bad outdrive all I will say is since 1980 I have had two problems. A slow upper gear case water leak and the water pump drive shaft splines went bad. The water pump drive shaft also drives the lower unit so that was a total loss of power. Still if I was sure I could get parts at a reasonable price I would still pick the OMC stringer outdrive as my outdrive. For me it has two major advantages. One it turns 90 degrees instead of 60 degrees so when your coming in to the dock and the wind is blowing you off the dock or the current is pushing you off the dock you can come in at a much lower speed. Second the outdrive tilts up all the way out of the water so if get some seaweed or line wrapped around the prop you can tilt it up above the water and unwrapp it. If you back in to a beach can get outdrive high enough to stay off the bottom. <br />Good Luck and please tell us how it works after your repears. Sorry I did not get back to you sooner, just been very busy here this spring.

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

Just a quickie before I go up to try out the fix. <br />Glad to finally hear about some one with virtually no problems. One of the biggest problems I have heard about the OMC is over heating. I suspect that this is due to some of these issues if you didn’t know what to look for you could easily do what was done here. As far as out drives go these are a little more complicated then the Mercs certainly not harder to fix. Unlike the merc that is more forgiving to little mistakes. I think with OMC you must be exact in the replacement. I like the manual although I wish I could find an OMC one it would have more detail. <br /><br />The friend who gave me the boat is also beside me so we can do the work together his new boat was an insurance buy out it was stolen from some poor sole. And it was left a mess. But it is coming together quite nicely. I just have to keep him on track instead of rushing it. So he has 6500.00 in it and it still needs to have the gauge wiring replaced and seats. It was repowered with a tallboy 6 150. We have since discovered that it was rated only to 120. Not something I would recommend but I do not think will be a problem. As I put to him just means he wont have to run full out all the time. <br /><br />But now he is thinking he may want to trade me boats since he really like the Renken but the over heating problem caused him to buy the other. I just told him he could use anytime time he wants. But she mine now. <br /><br />Besides she still needs a lot of TLC that he wouldn’t give her. He is the type who needs a turn the key type of unit. Where I believe unless I know it is right will not take it out. Can’t see how it would be enjoyable if your worrying whether you will make it back to shore. Last year when he got it before he even looked at he planed a trip to go boating and invited every one only to find out she needed a lot of work. Most of us sat on the shore waiting. Not a fun trip this is where I gave him the Nick Name of Gilligan. His wife has a great sense of humor. She wants to call the new boat Hopeit as in hope it floats hope it runs. <br /><br />Thanx for the reply Boatist I appreciate the input and I understand about busy I have to find the time as well to work on my boat. Will let you know how I make out.<br /><br />Alex

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

Update <br /><br />Discovered I actually have 2 starboard covers go figure but I got the water flowing actually had her running on the muffs. Got two good streams flowing on the ball gears. <br /><br />Although the one on the port side seems to be stronger. And before the thermostat opened the water was leaking from one of the hoses on the housing so for sure she has lotso water now if she still over heats then I will look at the elbow since it looks like whom ever been working on her likes the sillycon maybe a blockage here.<br /><br />On the muffs she is flowing and cooling let her run up too 3000 she ran up to 170 steady before I brought her back down. <br /><br />She’s nowhere ready for water trials yet. Carb leaking fuel the trim motor was removed and the jack goes to the bottom and weight of the engine rests on the water separator. Had to repair the controls before I tried to start her. Bunch of other stuff as well even the seats have to be secured.<br /><br />Will get some parts tomorrow and work some more. Finding a trim motor is going to be hard. I wonder if there is away to set and keep set at one level for now? <br /><br />Alex

 

[Boatist]

Re: OMC 120 1982 last of the stringers it seems.

Alex<br />Sounds like did not have much maintenance. Output of the exhaust manifold is pretty common place for rust and scale to plug up the output holes. In saltwater engines any rust or scale that flakes off the engine or exhaust manifold will end up plugging the manifold output or riser input. <br />Select trim engines had a motor to raise or lower the front motor mount and trime the boat. Manual trim just had a long bolt with some nuts to adjust trim where your want it. All you really need if you have trim tabs. My motor will run up to 170 degrees at WOT but anything slower it back down to 150 degrees.

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

Thanx again and your right I know my buddy doesn’t believe in it. Can’t blame him for all the problems he just didn't fix them. Since according the manual cleaning the manifold is part of regular maintenance I might just as well pull the riser and clean it up. But I'm kind of curious as to whether the work I already did will fix the issue so I may just wait then clean it anyway.<br /><br />On another note there is a name on her that I want to change but have been told this was bad luck. While this poor old girl has had all the bad luck she's going to have apparently not only has she suffered at the hands of neglecting owners but due to seal leaks she has been on the bottom a couple of times. I was thinking of Second Chance.<br /><br />Alex

 

[tryan]

Re: OMC 120 1982 last of the stringers it seems.

fix the fuel leak and make sure the blower operates. your safety is important.<br /><br />trim up to keep cool? sounds like you want to measure your water pick up hose at the gimbal also. it may be in a bind when you are trimmed down. a thin coat hanger in a drill works great on the passages of the risers. i know a few people that use krylon and rustoleum to lessen the speed of corrosion.<br /><br />try not to go much above idle when running on the muffs.<br /><br />my brother picked up a rebuilt trim motor for 125 bucks or so. i would clean it up and see if you can get it to work.

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

Thanx Tom for the input and for sure the first thing on the list is fixing the carb. But there is no hose the water passes up though passages in the out drive the hose starts inside the transom. So this would not be the problem, but I have seen this before. <br />I think the issue was the passages in the side covers were not lined up correctly blocking half the hole. If I could remember how it looked when I took it off. But I can say the since the port cover was replaced with a starboard I almost did it myself <br />I fit every thing first so I discovered this. Put sealer on everything since most of the holes are stripped tightened them in a sequence to get the most seal I could wait for the sealer to dry.<br />Lots of pressure now the water never leaked before and the streams which I think are output are very strong at the back now. Gilligan says this he never saw before. I have given my self some time to do this right I need to do some more work before I can take her out. But I think this is where the problem was. <br />The person who did this work was a butcher hell he even try to drill new holes for bolts though the cover. Good thing he missed. I have the trim motor out and it is gone I need a replacement. <br />Thanx again Alex

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

Update <br /><br />I got her out today and she runs great no more over heat yehaw. She fast for a 19' if I'm to believe the Speedo she was going 52 miles I've seen them read slow but not fast. The trim has been set in about the right spot, I think. She pulls hard gets up on plane fast. Tried several levels to find the correct placement then put the old motor back in place to hold until I get the new one. I'm sure the trim tabs help.<br /> She still needs allot of work but at least I have the over heat solved something all others that have worked on it couldn't do. Not bad for a systems engineer with a book even if I say so my self. <br />Still have lots of work to do before I make a family outing. But I on track for the July 1 weekend. <br /> <br />Thanx again for all the help and I'm sure I'll be asking again <br />Alex

 

[Boatist]

Re: OMC 120 1982 last of the stringers it seems.

Alex <br />Good Job! What cured the over heating, the pivot pin bearings or the manifold?

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

I wanted to see if the pivot pins did the job so I left the manifold to see and it was the way the work was done or should I say not done on the pivot covers and plates. There will be a lot of work in the fall on them repairing all the holes that got buggerd. But it will hold for now when I get her ready for the next year I will do a proper cleaning of all the manifolds then.<br /><br />Thanx again your help got me moving in the right direction.<br /><br />Alex<br />Let the fun begin.

 

[Fishermark]

Re: OMC 120 1982 last of the stringers it seems.

If the problem with the bolts is simply that the holes are stripped, then helicoil works good to repair them pretty easy. I am in the process of removing the OMC outdrive from my brother's boat, and I remember him having the same problem about ten years ago with the bolt holes being stripped out. I watched the marine mechanic use the helicoil inserts. Like I mentioned, it was quick and easy.

 

[Alexo1us]

Re: OMC 120 1982 last of the stringers it seems.

Update for those who have taken an interest.<br />I guess I'm getting older but I find that now things that would have made me through a wrench or two, Good thing too I don't think the fiberglass would like it.<br /><br />Anyway I got her out for her first run with her new owner she was very happy still looks like she has been around but this will also be looked after. I was running her up on the muffs saw other leaks but father up line. Some one said what a piece of S***. <br />Not wanting to sound rough in my reply. I thought about it for awhile and when though thoughts like Hey this is the last place it can leak, the next point is out side the hull and as far a I'm concerned it can leak all it wants.<br />To she’s good enough for you to want to ride in. <br />But I settled on, Ya but she is my piece of S***.<br /><br />Should have knocked on wood as now my manfold has developed cracks. Anyone have any luck welding these things.<br /><br />She is really not much but when you spend every night for 3 weeks you tend to get use to the personality of the thing. I have decided that she is worth the effort I don’t think I would pay to have it done. I can see why so many have the opinion that they are not worth it and even very good marine mechanics may think they could work on them there are so many subtitles it would be a right and wrong choice with a 50/50 chance of getting it right. So if your going to pay a guy to work on it make sure he has tons of experience on OMC or better yet if any still exist a factory trained guy. And learn how to do basic maintenance your self. All in all these drives are in my opinion, such as it is just as good as anything else from that era they just require a bit more maintenance. Not unlike some people I know. <br /><br />Thanx again for all the help.<br />Work in progress!!<br />Alex