Have Reverse/No Forward OMC 140

[mtodd101]

Hi all
I have a 1977 19 ft. Reinell with a OMC 140 Gm Motor. The motor is actually a 1976 (990236M). I was
given this boat with the motor not turning over and the drive not working. I've since got things working
fairly well until Saturday. Went out to check our crab pots and the boat wouldn't go into forward. It goes in
reverse fine. It all worked on the day before. All wires are connected at the remote throttle and I have
power at the wires going into the outdrive. I drained the oil from the outdrive, lower first and it had no sign of any water. Then the upper was milky. I'm not sure if its one chamber for upper and lower or are they
separate. I also noticed when we were out that when the outdrive bobbed under the water when running,
there was alot of foaming or bubbling from the drive. My question is, is there something I can check as far
as the "forward" problem before I pull the drive? I haven't pulled a drive before so I'm a little intimitated I
guess. Also when I do pull the drive I assume a seal kit will be needed along with a water pump/Impeller
since I'm in there. The Gimbal doesn't make any noise when turning but will check that also. There is no
water coming into the bilge. I not sure what the Bellows look like. I guess I'll find these things out as I go.
One other thing, when I put the garden hose on the drive, water seems to come out everywhere. I don't
know if this normal as this is my first boat. Thanks for any help you can give. Matt

The boat has New
Battery
fuel filter
Coil
Cap, points, rotor and condenser
Water pump
Rebuilt Rochester 2B carb

 

[Howard Sterndrive]

Re: Have Reverse/No Forward OMC 140

seeing as you have power to the light blue and light green wires to the drive, the wiring harness inside the drive casing may be the issue. You also need to use proper oil in the lower (Type C), water or wrong oil can cause the magnet to be too weak to engage the clutch spring.
After that checks out, you have an internal problem.
You can check resistance with the wires disconnected - should be 4-7 ohms on either F or R wire to good ground.
pulling the drive is quite easy.

 

[mtodd101]

Re: Have Reverse/No Forward OMC 140

Thanks for the reply' Howard. I just checked the resistance in the wires going to the outdrive and I have 4-7 with the blue wire and 0 at the green wire. I have been using type c oil in the lower and hi vis in the upper and intermediate. The family I got the boat from said they had kept up on the
maintenance and I don't have any reason to doubt them. I changed the oils when I got the boat.
So what's your best guess. Is it possible the wires are bad or something bigger. Thanks again. Matt

 

[Redrig]

Re: Have Reverse/No Forward OMC 140

If you have 0 Ohms on the forward wire, the coil is either shot or the wire has a bad connection somewhere in the lower unit.

I am in the process of tearing down my spare lower and repairing a broken forward spring, I initially though my coil was bad but it turned out to be the spring

 

[mtodd101]

Re: Have Reverse/No Forward OMC 140

Hi Red. Thanks for the reply. I haven't taken my OD off yet so I don't know what is wrong.
A broken wire would be nice as I could identify that fairly easily. I'm a little nervous about the teardown, but you don't learn without some effort, right? So are you replacing or repairing the spring
on yours. Can a break in the spring be welded back together? Where is a good source for quality
parts?
Thanks again Matt

 

[Howard Sterndrive]

Re: Have Reverse/No Forward OMC 140

0 as in zero ohms? or the meter reads "OL"?

0 ohms would be blowing a fuse, and that same fuse feeds forward too, so I don't understand how that could be.

 

[mtodd101]

Re: Have Reverse/No Forward OMC 140

Hi Howard
My manual say to check ohms from the green and blue wires going to the sterndrive. One lead to the green/blue wire and other to a good ground. Should get a range of 4.5-6.5 which i did from the reverse wire and I got 0 ohms from the forward. Manual says if the reading is not within given
range, a wire is broken or the coil in the sterndrive is shorted. I'm not sure how this all works yet. I'm assuming that when the is current is applied to a given gear, as in for/rev, it moves the that gear and engages the prop shaft and the prop starts turning. Power to both gears at the same time
would cause shearing of opposite gears and/or shaft. I'm going to build a stand for the OD this weekend and start taking it apart...slowly with pics so hopefully I'll be able to put it back together. Thanks Matt

 

[Howard Sterndrive]

Re: Have Reverse/No Forward OMC 140

0 ohms means a dead short. could be a fried coil in the lower unit, or could simply be insulation rubbed through on a wire in the lower harness inside the drive, and bare wire touching the case.

 

[Redrig]

Re: Have Reverse/No Forward OMC 140

Hi Red. Thanks for the reply. I haven't taken my OD off yet so I don't know what is wrong.
A broken wire would be nice as I could identify that fairly easily. I'm a little nervous about the teardown, but you don't learn without some effort, right? So are you replacing or repairing the spring
on yours. Can a break in the spring be welded back together? Where is a good source for quality
parts?
Thanks again Matt

Taking off the OD is not all that hard, just have a helper handy to hold the weight of it while you are loosening the bolts at the pivot point.

A broken wire would make more sense for reverse, I was talking to an old school mechanic about these and he said that those Reverse wire will usually rip when a rope gets caught in the prop, the prop twists the reverse coil in the OD and will tear the reverse wire. the forward wire he said will usually survive that. which makes sense, its hard to explain but once you are in there you will see what I mean, there is nothing that actually holds the coils in place.

as far as I know there is no welding a spring back together, there is a little tang on the end that is usually the failure point. I did however read on here about a guy who got a torch and heated a broken one and made a new tang, he used that for his reverse spring since reverse failing is not as bad as forward.

as far as parts go I usually just check Ebay, there is some good stuff from time to time on there for cheap if you have time on your side. luckily I have a backup lower for mine that is running good so the one I am repairing I can take my time, I have a new seal kit and just waiting for a "new" spring to pop up on Ebay for a decent price and I will start getting her back together.

 

[mtodd101]

Re: Have Reverse/No Forward OMC 140

Hi Guys. Thanks for the replies not only to my problem, but all the posts here. Many of us would
be lost without them.

I found this link from 2002
with a similar problem as I'm having. Here's what his problem fix was.


"I had a similar problem that turned out to be a broken spring. Here's how my mechanic had me diagnose it:

1. I connected a volt meter between the shift coil wires (behind the engine port side) and the block, one at a time, then shifted into forward and reverse to verify the shifter was sending 12V. If I'd gotten no voltage from one or both wires, I'd have had a wiring problem from the shifter. Since I got 12V with the shift lever in both positions, I continued to step 2.

2. I checked the coil by connecting an ohm meter between the reverse coil wire going into the upper drive unit and the engine block. No continuity would have suggested a bad coil or lead. I got continuity, so I checked for a broken spring.

3. I reconnected the shift coil wires and, WITH THE ENGINE OFF, I manually rotated the prop clockwise, while an assistant shifted into reverse. The prop should have stopped completely, but it didn't, so I had a broken spring.

Reverse problems are a pain because you have to dismantle everything to get to them. But, with that said, my mechanic had it repaired in a couple hours."


I tried this with my boat and in reverse the prop stopped. and in forward the prop continued to spin. so maybe it's a broken spring. We'll see. Going to finish crab season this weekend with my 14ft Lund and then tear the out drive apart. I'll post what the problem is when I know. Thanks again for the help. Matt

 

[mtodd101]

Re: Have Reverse/No Forward OMC 140

Wow, just found a coil spring for @250.00 and a Elec. shift coil for $140.00. Is this about the going rate? The shift wire is about $80.00-$100.00. Free boats are expensive. Well I can't pull a skiier,
but I can go a full crab season on 2 gallons of gas with my Lund. Would buying another outdrive be
a good way to go? Parts would come in handy I'm sure. I found one locally, asking $650. Not sure
if that's a good price or of the condition. Thanks Matt

 

[Howard Sterndrive]

Re: Have Reverse/No Forward OMC 140

Would buying another outdrive be
a good way to go? Parts would come in handy I'm sure. I found one locally, asking $650. Not sure
if that's a good price or of the condition.

 

[southkogs]

Re: Have Reverse/No Forward OMC 140

Maybe look around a little. I had some lower unit problems earlier this year - chasing gremlins kind of like you are - and kept a watch. I bought an entire (not working) stern drive for $75 to keep around for parts, and an entire working stern drive for $400 (on the boat and working now). Can't promise you'll find a working one, but donor boats are a little more common than you might think.

 

[southkogs]

Re: Have Reverse/No Forward OMC 140

lol