OMC Control Box

[79Rude115]

I have a 90 Four Winns Horizon 200 with an OMC 5.7. I have had problems with the shifter, it is difficult to get it to go into neutral, when the shifter in in the neutral position sometimes the boat is still in forward or reverse and you have to shake the shifter to get it to come out of gear. There does seem to be a little extra resistance in the shifter particularly around the neutral position.

I had the drive pulled last season and the mechanic said the problem was with the control box, he said they don't service them and that I would need to get a new one. I have the repair manual and it describes how to rebuild the hideaway control box.

So the question is...does anyone agree with the mechanics diagnosis? Can anyone provide insight into other things I might check and or tips on rebuilding the control box?

 

[Bondo]

Re: OMC Control Box

Ayuh,... I'd sooner think your problem lays with the ESA module, Not the controller...

 

[79Rude115]

Re: OMC Control Box

ok, can someone give me a basic test procedure for the ESA? Assume I just start it and manually engage the esa switch to listen for a change in idle?

 

[wire2]

Re: OMC Control Box

ok, can someone give me a basic test procedure for the ESA? Assume I just start it and manually engage the esa switch to listen for a change in idle?

That should tell you. I'm guessing it's a similar setup to what I had, an '84 OMC 5.7 with an 800 stringer. Manually pressing the limit switch would drop out every other cylinder, dropping the rpm to ~300.
As I understand, the Merc cuts the ignition completely for the duration of shift resistance.

 

[bruceb58]

Re: OMC Control Box

ok, can someone give me a basic test procedure for the ESA? Assume I just start it and manually engage the esa switch to listen for a change in idle?

That is correct.

You have a few potential problems. The first one is that your lower shift cable needs adjustment or is failing. That is the most likely. Take a look at the shift housing where it enters the drive. You can see it with the drive tilted up from the starboard side. This is where these cables often fail.

The other is if your controller has a lot of" lost motion" because of wear. Not as likely as the first. Make sure that you shift cable from the controller back to your engine is tied in place along its entire length so that it doesn't move. You can get a lot of "lost motion" if that happens and it effectively limits the throw of the controller.

Don't drive your boat until you get the adjustment fixed. By the way, the ESA should never engage when you run the boat on muffs. It needs the force of the water on the prop and thus the gears to cause it to be needed. If the ESA engages when you are on muffs, it ,means your lower shift cable is requiring extra force to make it move...also means it needs to be replaced. These cables go out often, I was replacing mine every 3 years it seemed.

I have a feeleing your mechanic may not have experience with OMC Cobras. Is that your feeling as well?

 

[79Rude115]

Re: OMC Control Box

Thanks gents - and apologies for the delayed response

You have a few potential problems. The first one is that your lower shift cable needs adjustment or is failing. That is the most likely.

I have a feeleing your mechanic may not have experience with OMC Cobras. Is that your feeling as well?

I checked the mechanic out before I took him the boat, I was referred to him by the dealer that originally sold the boat. I was told by the mechanic and the dealer that they are OMC experts. So I think he knows OMC well

The mechanic changed the gimbal last summer and I told him about the problem before hand so he checked the lower shift cable resistance and wear while the drive was off and said everything looked fine.

I do not think the upper cable is secure all the way to the engine, in fact I am almost sure it isn't. It would be great if this was the problem because it would be an easy fix.

I did notice one thing I thought was odd about the control box, instead of being mounted exactly perpendicular to the shift lever it is angled upward with the back of the control box (where the cables enter) higher about 15 degrees. There are several mounting holes so it looks like it could be changed if that isn't correct.

 

[HT32BSX115]

Re: OMC Control Box

You could look into another control. I installed a Teleflex CH1700 in my boat when I pulled the Cobra. The control was 20+ years old and was fairly worn out.

I was told by the mechanic and the dealer that they are OMC experts.

That of course, doesn't make it so.......


Ask the mechanic if he knows about the clutch dog changes and lower shift cable TSB for older Cobras. Ask him if he knows about the Stuart Hastings info

Also, ask to see his OEM OMC service manual for the correct year model of your engine and drive.

If he gives you a "Deer in the Headlights Look", or he says he's using a Seloc or Clymer manual, then he might not be the "Expert" that they claim.


Cheers, Rick

Also

 

[bruceb58]

Re: OMC Control Box

Those control boxes do wear out but I would still be suspicious about the lower shift cable. Also, not sure if you have ever used this boat in salt water but the area where the lower shift cable connects to a bellcrank in the drive can collect salt water and over time can get gunked up with deposits. Whenever you take your drive off for inspection, you should clean it out and fill that pocket with grease.

 

[JMC69871]

Re: OMC Control Box

I had the same problem with my '92 OMC 5.7. I replaced my lower shift cable and aligned it and the problem still existed. It ended up being that my upper shift cable that runs from the control box to the motor was worn as well. If the cable is worn or stretched it won't fully disengage the drive out of gear. You should definitely make sure all your shift cables are in good working order as well as your ESA because the last thing you want to do is eat up a gearset on a Cobra. Hope this helps.

 

[79Rude115]

Re: OMC Control Box

Thanks all, I will test the ESA and check the upper shift cable. I think I should be able to tell if the upper shift cable is bad by disconnecting it at the motor and testing the drag, imagine it will be very easy to shift when disconnected from the motor is the cable is good. Any other tips are always appreciated.

 

[79Rude115]

Re: OMC Control Box

The first one is that your lower shift cable needs adjustment or is failing. That is the most likely. Take a look at the shift housing where it enters the drive. You can see it with the drive tilted up from the starboard side. This is where these cables often fail.

You are wise Sir, that is indeed the problem. After testing the upper cable I looked under the drive and see that the lower cable is split and rusting.

I have a feeleing your mechanic may not have experience with OMC Cobras. Is that your feeling as well?

Again you are probably right. Given that I told the mechanic I it was not shifting very well and asked that the lower cable be replaced while the drive was removed if it looked remotely worn...I am not sure this mechanic should be trusted with a lawn mower.

I am calling the mechanic to let him know that they missed this and see if he offers any resolution, if I don't hear what I want I guess I will be hunting a new OMC mechanic to change the lower cable. I am very mechanically inclined but something about removing the drive myself scares me.

 

[bruceb58]

Re: OMC Control Box

Removing the drive is normally pretty easy as long as nothing gets stuck! You should be doing this annually anyway so you can check alignment and lube/check u-joints and gimbal bearing.

As far as changing the shift cable, that is a little more tricky because of the adjustment procedure.

 

[79Rude115]

Re: OMC Control Box

Well I talked to the owner of the shop, he was apologetic and thought the oversight could have been to the rush around 4th of July. Said he would take 33% off of the labor if I bring it back for the shift cable. Basically 2 hours of labor plus parts, for some reason the lower shift cable is over a hundred dollars??

He also said if the bellows were bad he would only charge me for the parts.

I asked him if he was familiar with the adjustment of the shift cables and he said he has been working on them since 82 and is a certified OMC mechanic so I think he has got it down. I guess he had someone working on the boat that wasn't a certified mechanic...

 

[duke3478]

Re: OMC Control Box

I am very mechanically inclined but something about removing the drive myself scares me.

It really is pretty easy. It's removing one nut to get the trim/tilt rod out, then six 5/8 nuts on the drive. You can pull the drive right off. It does weigh about 70-80lbs, but if you're careful and have somewhere to put it it's not a big deal. I use an upturned barstool.

The lower shift cable can be difficult to get in and out. Cut the old one, which makes it easier to turn the hex coupler at the drive. When you put the new cable in, you can temporarily reroute the hose it runs through to make it easier. Lube the inside of the hose with soapy water, and have a buddy carefully twist the cable inside the hose to match your turns while you tighten the coupler, and you're good. The rest is straightforward.

I usually need a helper to hold the u-joint in place when I slide the drive back on, and to hold the tilt plate flat, but that's about it.

 

[duke3478]

Re: OMC Control Box

Well I talked to the owner of the shop, he was apologetic and thought the oversight could have been to the rush around 4th of July. Said he would take 33% off of the labor if I bring it back for the shift cable. Basically 2 hours of labor plus parts, for some reason the lower shift cable is over a hundred dollars??

Seems a little high, when you can get them right here on iboats for just under $90. A shop is always gonna charge you more than their cost, though.

 

[bruceb58]

Re: OMC Control Box

Seems a little high, when you can get them right here on iboats for just under $90. A shop is always gonna charge you more than their cost, though.

I would not go through all the effort and put in the Sierra cable. You can still get the OMC cable and that is what I would use.