OMC shifting problem

[OmcOwner2]

Hello iboats people. I'm new to the site and have a question for whoever is willing to help I bought my first boat and I am in the process of fixin her up. Its a 17' with a 1978 omc 140. Well I put it on the water for the first time about a week ago. After taking care of most of the problems in my shop, there were only a few small issues after getting it in the water. Got them all fixed except for this shifting problem. It seems to go in to forward and fine, it's getting the darn thing back in to neutral thats a problem. After putting the boat in neutral it stays in gear for 5-10 seconds and then pops out. Some times it wont' even come out of reverse at all. The boats shifts just fine on land. After some more reading of my Seloc manual I took it out today and tinkered some more. I took the cover off the shift converter and shifted it by hand everthing seemed to be fine. I then decided to lower the idle as low as possible (about 300-400 RPM I would guess). The boat then shifted to neutral with only a second or two delay. Any thoughts?

 

[OmcOwner2]

Re: OMC shifting problem

Okay I got some more time to work on the boat today. I ran it on the muffs in the back yard and it shifts fine while not under load. After much reading on this site it sounded like a shift interrupt switch problem since it shifts better at very low rpms. Checked my manual and it doesn't appear that the '78 140hp manual shift has one, unless the neutral switch serves both purposes somehow? Only wires coming out of the control box are the 3 for the trim and 2 for the neutral switch. Starting to think my problem may be in the lower unit. Any help would be appreciated.

 

[Haut Medoc]

Re: OMC shifting problem

Not sure if your model has a dog clutch, but it sure sounds like it & that would cause your symptom .ie shifts w/o load, won't with load....
I don't know enough about OMC to help you but there are members here that do.....
Post up your serial # if you can, I'm sure it will be helpful....
Welcome to iboats, BTW .......JK

 

[Gary H NC]

Re: OMC shifting problem

Its a 78..i guess thats a stringer drive. electric shift?

 

[bruceb58]

Re: OMC shifting problem

78 should not be the electric shift.

I can see a couple possible problems. One would be a shift cable that is failing and the other that there is some lost motion in the control.

When I had an OMC Cobra, which is the model after yours, I has similar problems with adjusting the cable so that when I put it into neutral from either the forward or reverse direction, it stayed in the previous gear. Turned out that there was so much slop in the control that I wasn't getting the full throw on the cable.

Either a bad cable cable or a bad control could give you similar problems.

 

[whywhyzed]

Re: OMC shifting problem

My guess:
Someone has put a 1981-1985 outdrive on your 1978 boat.

1978-1980 were hydromechanical shift drives. They used an internal hydraulic pump and servo cylinder to shift. They shifted smooth, but those drives were junk and rarely lived more than a few years before self destructing.

The 1981 on drives were full-mechanical shift, which means they require an ESA (Electronic Shift Assist) module, which stumbles the engine whilst shift to neutral to allow the gears to unlock.

 

[bruceb58]

Re: OMC shifting problem

Hmmm...I forgot about those years with the hydraulic assist shift.

 

[OmcOwner2]

Re: OMC shifting problem

Thanks for the input all. My manual says it should be the hydraulic assist shift model. I'm guessing I would have to take the lower unit off to know for sure what it is? I forgot to mention the guy I bought the boat from said he had just paid a shop $2500 to put a new lower unit on the boat (it's green instead of white). Also the cable out of the shift converter to the lower unit does seems a little stiff when going to reverse. It's also kinda feels like its in a bind when coming out of reverse and in to neutral. Everthing from the control box to the shift converter seems ok. I should have time to play with it more tomorrow.

 

[whywhyzed]

Re: OMC shifting problem

that's interesting information. The "fix" for the hydro lower for the last 2 decades has been to toss it in the scrap bin and put on a full mechanical shift lower unit, then install the ESA system.

Green? that's weird. Omc sterndrives have been a lot of different colours but never green.... almost makes me wonder if somebody modified a Johnson V6 lower unit to fit... haha the housings were the same dimensionally... never tried bolting one up. I don't think it's possible.

The part number on your shift cable (about 1.5 feet from the shift converter box...embossed in the rubber covering) will tell if it's hydro or full mech. without disassembling the drive.

I bought a 1980 parts boat last summer for $150 off this lady.... this guy kept crashing into the dock and other boats, and I think the wife sold me the boat out of fear for her kids.... guess what the problem was?.... the drive was silver...(1984/85 colour)

 

[OmcOwner2]

Re: OMC shifting problem

Ok I got the part number off the shift cable. It is 982802. Also got a pic of green lower unit.

 

[Gary H NC]

Re: OMC shifting problem

I have noticed some places that sell replacement drives paint them some kind of primer green..

 

[OmcOwner2]

Re: OMC shifting problem

The "fix" for the hydro lower for the last 2 decades has been to toss it in the scrap bin and put on a full mechanical shift lower unit, then install the ESA system.

I wonder if the previous ower did convert it to full mechanical shift and but never put the esa system on?

 

[whywhyzed]

Re: OMC shifting problem

982802 is the cable for a mechanical shift lower. That lower requires an ESA system be installed on the boat. Failing to in install an ESA makes the boat dangerous, and you'll probably break your shift cable after a couple hundred shifts.... look on eBay or in a wrecking yard for the proper shift converter box, switches. Then buy the ESA module from Rapair.

So the guy paid $2500 for that eh.... typical crappy service....I would like to be an expert witness in court when someone gets killed in a boat put together like that, send the clown to jail.

The good news:
Once you get a working ESA system on there, those lowers shift butter smooth in and out of gear. Mine feels like a velvet drive when I set the idle rpm down to 650 or 700.

 

[OmcOwner2]

Re: OMC shifting problem

I have noticed some places that sell replacement drives paint them some kind of primer green..

Now that you mention it, it does look like primer.

 

[OmcOwner2]

Re: OMC shifting problem

So I need a converter off of a '81-'85? Do I need to change my control box as well?

 

[Boomyal]

Re: OMC shifting problem

OmcOwner2, not sure where Milan Wa is but we unargueably have one of the most knowledgable OMC experts around these day, right down on the Columbia River. People and dealers ship him drives from all over the country, including Alaska. Steve Ryan at Ryans Marine 503 282 8807. If you call him tell that Gyro Gearloose sent you.

As mentioned, unless someone has put on an outboard lower unit, you do have the hydro-mechanical 800. There are modifications that overcome some of the deficiencies of the HM drive. I've had mine since 1979 and finally just had Steve go thru it last summer so they are not that horrible for medium size boats.

EDIT. I just saw your picture OMCOwner. Your drive is the later Mechanical Drive. If someone did not change the converter and hook up the shift interupt, you will have problems. If you could get a picture of the converter it would tell the story. On the possibility of it being an OB lower, I dunno. Not familiar with their similarity of appearance.

 

[OmcOwner2]

Re: OMC shifting problem

Thanks for the info boomyal. I may just give them a call. Oh and Milan is about 20 miles north of spokane. Not too far from the columbia

 

[OmcOwner2]

Re: OMC shifting problem

Should I get a pic of the converter with the cover on or off or both?

 

[OmcOwner2]

Re: OMC shifting problem

Here's one pic let me know if ya need more.

 

[Boomyal]

Re: OMC shifting problem

Here's one pic let me know if ya need more.

Don't see one Omc!

Yeah, you'll probably need to change the shift box to one that can accomodate an interupt switch. Your cables should be reusable. Steve would know these things and may even have something used.

For sure, just a little jaunt down the Columbia!