OMC Cobra 5.8 stalls when put into gear at idle

[kadaro]

I have seen various posts on this......and need help

My 1992 OMC 5.8 ford cobra sterndrive idles nice and after warm up stalls when putting it into gear.

If I quickly give it some gas, it gets past the stall point, it runs OK. All runs great even at full open.


Idle at warm up, in the water, is around 850. I know you guys preach 650RPM for the dog style clutch....but I doubt I can idle that low without stalling even worse.

The interupter is not the issue...it is in the neutral indent. Shifter and cables seem OK. Occurs at any postion of vertical drive/trim.



History, the carb was professionally rebuilt, and has new fuel pump end of last season...it had other issues which are now resolved. But it had this problem even before the rebuild.

Any suggestions would be appreciated.

Thanks

 

[rybad]

Re: OMC Cobra 5.8 stalls when put into gear at idle

How are you sure it's not the inturrupter? Personally, that what is sounds like to me. You can get replacement for about $40-$50. (If you have twin drives, swap them.. thats what I did when I was having similiar problem, turns out one of mine was bad.) Now, I idle about 750 and have no problem.

 

[Boatin Bob]

Re: OMC Cobra 5.8 stalls when put into gear at idle

Unplug the 2 wire (purple and gray) to elminate the ESA and see if it makes any difference.

 

[kadaro]

Re: OMC Cobra 5.8 stalls when put into gear at idle

I'm going to review the interupter again.
I do recall unplugging it for a test and recall the same result (at the dock). ..... but I've been over alot of things since. I'll try again in open water.

One other clue....Once shes warmed up after a run....I don't have the stall issue but can slightly feel it....

Also, I have a slight shift issue. When going from forward to neutral..sometimes she sticks in forward and I have to go reverse to release it. I'm guessing I need to slightly adjust the lower shift cable.

Let me know your thoughts...I'll check deeper this weekend....

 

[Don S]

Re: OMC Cobra 5.8 stalls when put into gear at idle

Try the adjustment first. If you are hitting the overstroke switch it will also engage the ESA. One NOTE: the ESA does not Kill the engine, it stops spark on half the cylinder, if your engine dies, you may have some running issues to.
You might also want to review some of this information.
http://www.hastings.org/~stuart/cobra/index.html
Do you have an OEM service manual to do all these adjustments by? IF not, you will likely never get it right.

 

[kadaro]

Re: OMC Cobra 5.8 stalls when put into gear at idle

Hi Don, Your quick on the replies...thanks


I don't see an overstroke switch on this one; would it be by the interupter someplace...or by the controls?

I have the Seloc manual..and the factory Stern Drive AMH Vertical Drive Install manual. It is clear on the Cable/Interupter adjustments....but no mention of a overstroke switch.

I've seen the instructions you referred to...its not quite applicable to my system.....unless I overlooked something.

 

[Don S]

Re: OMC Cobra 5.8 stalls when put into gear at idle

I see the 92's didn't have the overstroke. 91 was the last year for that.
Sorry, I'm not an OMC person really. I just get stuck working on it.

 

[kadaro]

Re: OMC Cobra 5.8 stalls when put into gear at idle

I just read through that theasus of a document....wow..good to know. But I think/hope my unit is beyond those issues. My sn ends with AMK and may have all the improved fixes. However, I gained some good insight to whats going on with the ESA and Interupter. Not to say AMK is exempt from those quirks.

My boat is in the water, I'll try to go through the adjustment checks.

If it would help...I'll scan the factory Stern Drive Install Manual (1991) "AMH" model (guess mine is similar) and post them up. If anything, it will be a good reference for those who don't have it.

Please do a dig and let me know if you have a bulletins specific to my drive....

FYI: I think you and others who contribute to this forum are a valuable asset to all the boat owners out there....keep up the great work!

 

[kadaro]

Re: OMC Cobra 5.8 stalls when put into gear at idle

Hi all,
Just so it helps someone else....I found the primary cause.

I have the prestolite distributor.
I simply pulled the cap, electonic module...cleaned it up abit and use contact cleaner/lubricant. Cleaned up the rotor and distributor cap contacts and its running much better at idle. I will order replacements but at least I'm good to go after a warm up for a few minutes.

I suspect the boat sat a few years and/or had little use before I picked it up last fall.

As for the cables....I went through the adjustments in the factory stern guide, frankly I think theres a lot of latitude for the adjustments on this year/model....

I'll be planning to pull the stern drive end of year and replace all the rubber hoses, bellows and shift cable for good measure.