Older OMC (1981) Problems

[Martin Leaney]

I am looking into buying a 1981 Chris Craft 253 with an OMC drive. There is a reputation that OMC has and after doing a search here I have more information but not for the pre 1989 models.<br /><br />Am I asking for troubles with the older OMC or are the problems not manufacturing related?

 

[Bondo]

Re: Older OMC (1981) Problems

They were Junk the Day they rolled out the door....

 

[Mufasa]

Re: Older OMC (1981) Problems

The OMC units we call "stringer drives" have not been produced since 1985 when the cobra drive came out. It has many weak areas and is very expensive to repair. Many shops do not want to even service them anymore. It is very hard to keep it operational and warranty the work done.

 

[Boatist]

Re: Older OMC (1981) Problems

Cpt Muddy<br />I do not disagree with either of the first two comments but have owned a 1980 Series 400 140 HP stringer unit since 1980 when I bought it new. Two reasons I pick that unit for my boat is motor turns 90 degrees instead of 60 degrees like others. This allows you to come into the dock slower when the wind is blowing or the current is pushing you off the dock. also by backing to gain sternway crank motor to port and put in forward boat will almost swing in it own length. Other thing is prop lift all the way out of water. Can clear of weeds lines or change the prop while on the water if need to.<br /><br />Problems I have had since 1980. Seal around motor cracked and leaked water into boat. Fixed that my self took about 1 hour and part cost about $60. Exhaust manifold rusted thru and leaked water. Also fixed that my self took about 4 hr, (did a lot of painting). Parts around $160. Getting water in upper gear box took that to a dealer to have resealed and change water pump. Cost $400 and he tried twice but stilled leaked slow so changed oil offten. Last year shaft that drives water pump and drive shaft failed, boat stopped dead in water and had to use kicker to get back.<br />About 50 precent of the dealers did not want to work on a stringer unit. The one that would do for $700 shop looked so bad would not let then work on my lawn mower. Took it to a place with a OMC master tech. They put in new water pump replaced both shafts and sealed the upper unit so no longer leaks Cost $1003 and down for two weeks. Also replaced thermostat one time and voltage regulator and of course spark plugs and point just as normal maintenance.

 

[Martin Leaney]

Re: Older OMC (1981) Problems

Thanks guys!<br /><br />What are the upgrade options on these stringer units? <br />Can they be rebuilt effectively to cure the problems? <br />Are most of the problems in the drive or the motor? I think the broker said it was a Crusader.

 

[adrew]

Re: Older OMC (1981) Problems

I have a 1985 series 400 as does boatist. It too had a water pump/drive shaft failure 3 years ago and has a leaky upper gearcase which was resealed but still leaks.(I change the oil every 2 or 3 trips) Other than that it has been routine backyard maintenance. I do like the little 4 cylinder engine. I guess the drives are the trouble makers.

 

[John Smith]

Re: Older OMC (1981) Problems

I also recently bought a 72 OMC 225HP Elect Shift out drive with a V8 GM motor, right after I took it out for a ride, and the upper and lower gear case has water and right away I replace the sealing but it still has small leak I found out the OMC sealing design in the upper and lower gear case was very poor. My question is can we replace the OMC drive with a much more reliable used brand, without costing an arm and a leg. Or replace a diff. used brand may need to re-glass the opening? The motor has been rebuilt recently and it runs extreme well. Any suggestion! What brand and cost?<br />John 1-21-03

 

[butch290]

Re: Older OMC (1981) Problems

bondo, AMEN

 

[Martin Leaney]

Re: Older OMC (1981) Problems

Sorry to hear that John. I'm trying to keep myself out of the same situation!

 

[Boatist]

Re: Older OMC (1981) Problems

Muddy<br />The motors are the same as Merc or Vovo and all have same Exhaust manifold issue. The OMC engine before corbra mounts different. Basicly you must remove the outdrive and motor and seal up the hole in the transom. Find a template for new outdrive and drill new holes. Put in new motor mounts. Attach new outdrive to motor and boat. I have no idea of cost.

 

[Martin Leaney]

Re: Older OMC (1981) Problems

Thanks Boatist - at least there is a solution if a guy gets too frustrated with the OMC leg. <br /><br />Although I'm not a mechanic I have a shop with most of the tools and equipment so I can pull the boat inside during the winter months and work in comfort and at a slower pace. I also have most woodworking machinery too for the interior work.<br /><br />Another question (or 2) - How much more is a fresh water boat worth as opposed to one moored and used in salt water? What should a guy look for as tell-tale signs of problems with salt water boats?

 

[John Smith]

Re: Older OMC (1981) Problems

Does anyone out there (or an OMC master mechanic, ) have a success solution of the sealing the upper and lower 1972 electric OMC gear case, Use a different gasket sealant, thicker or adding addition O ring, seal all screws? Certain area is most likely leak when under vibration? On another forum someone had mention the upper Gear Housing Stringer 800 out drive should drill 1/4 hole and place a bolt or split pin in the water Pump shaft, to reduce the vibration and failure of the drive shaft. Does anyone known how these was done (I think they are talking about shaft #21, 382883 and #28, 909753 connect them together by a bolt) and the out come of these modification? Your inputs are most appreciated.<br />John 1-22-03

 

[hondon]

Re: Older OMC (1981) Problems

The sad fact of the matter is,these units just have too many points of entry.Reseal is practically impossible.However one of the fastest sterndrive boats I've ever been in ,was an 260/800 Bayon.

 

[Boatist]

Re: Older OMC (1981) Problems

Muddy<br />I am not sure I can answer either question. For salt water problems look for rust in general. Exhaust manifold biggest problem. You can pull the front inspection plate off or take off the riser and look for rust and scale, but only if they allow that. Even then I not sure you can be sure.<br /><br />John Smith<br />I think the key is getting the right place to work on it. My unit would take 4 two hour trips before I could detect water for us that was about 2 months. I think that some places do not replace every seal. Even if they do the shafts that rotate can be worn where the seal runs so need to replace the shaft. There are places that totally rebuild the gear boxes, mic and replace all the worn shafts ect. Here at I boat they have about 4 vendors that do this work. They send you a rebuilt unit and you put it in or have put in, then send back the old core for credit. For non commerical they warranty for 12 to 18 months. You can check it all out at the top of page.

 

[Salty Dog]

Re: Older OMC (1981) Problems

How can I tell if mine is a stringer drive? Does anyone have a picture?

 

[Boatist]

Re: Older OMC (1981) Problems

Salty Dog<br />To start with what year is it. I think the change over to cobra was 1985. How does the out drive raise (tilt), two hydrolic cylinders (cobra) or a big gear on port side (Stringer). How does trim work, raises front of engine (stringer) or two hydrolic rams (cobra).<br />One picture of stringer engine in boat pictures in boating. It is the blue OMC V8.

 

[Barracuda_Lounge]

Re: Older OMC (1981) Problems

My last boat had a 1985 OMC 800 (Stringer). I got pretty good at removing the outdrive and repairing what was wrong. The reason I got pretty good at repairing the stringer is because it was always in need of repair. In other words, run for the hills if you see one coming. Or get very good at repairing it. You might want to do some research on part suppliers. Your going to need them. By the way, don't think you can leave it to your friendly neighborhood marine service center either. Stringers invented the acronym:<br />B-O-A-T (BOut Another Thousand). Good Luck!

 

[Barracuda_Lounge]

Re: Older OMC (1981) Problems

My last boat had a 1985 OMC 800 (Stringer). I got pretty good at removing the outdrive and repairing what was wrong. The reason I got pretty good at repairing the stringer is because it was always in need of repair. In other words, run for the hills if you see one coming. Or get very good at repairing it. You might want to do some research on part suppliers. Your going to need them. By the way, don't think you can leave it to your friendly neighborhood marine service center either. Stringers invented the acronym:<br />B-O-A-T (BOut Another Thousand). Good Luck!

 

[proline2]

Re: Older OMC (1981) Problems

Salty Dog<br />Note that a stringer system can have either a worm type trim assembly which raises the front of the engine or the hydraulic cylinders up front which do the same thing. My 84 800 has the hydraulic cylinders up front on a 3.8 v6.