OMC 2.3 cannot shift w/o stalling

Brads 99

Recruit
Joined
Aug 24, 2014
Messages
5
Hi all,
Looking for any suggestion on what to check next. I just bought a 1988 with OMC Cobra 2.3L
Problem:
Engine runs great for first run on the water 10-20 minutes. (should have taken a longer test drive)when throttling down to neutral, gets really rough or stalls. After that, cannot get out of neutral without stalling. similar results on muffs for 20-25 minutes. Temperature is good. Runs really strong when going.
Work done this season:
Carb rebuilt, wires, cap, rotor, cleaned contacts, timing belt appears in good shape.

Any ideas what would cause this after running for a while.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Howdy,


Welcome aboard!

Sounds like it might be fuel related. After it quits, try removing the fuel cap and see if you hear a loud "sucking" sound. (like vacuum in the fuel tank)

If you do, the fuel tank vent line is kinked or plugged with bugs or other debris.


Regards,


Rick
 

Brads 99

Recruit
Joined
Aug 24, 2014
Messages
5
Plan on taking it out tomorrow. Will do, thanks. I did try blowing in and could hear air passing back through after. I guess that doesn't mean it's clear enough to vent when needed. Hopefully that's my issue. I'll update.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
(should have taken a longer test drive)when throttling down to neutral, gets really rough or stalls. After that, cannot get out of neutral without stalling. similar results on muffs for 20-25 minutes.
Now there could also be another issue. If the engine gets "rough" and quits when you move the throttle/shifter from FWD or REV to Neutral your lower shift cable *could* be either mis-adjusted, binding or something in the shift mechanism is binding and could be activating the ESA when it shouldn't.

This would not be a "time" thing though. It would do it every time you tried to shift to neutral, hot or cold.

You probably need to know how that thing works. Have a look at the following info. It's a pretty good explanation of the Cobra in general.

http://www.hastings.org/~stuart/cobra/
 

Brads 99

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Aug 24, 2014
Messages
5
Thanks for the help. I got it out and moving pretty well, but it died out about 15 minutes at full throttle. Finally decided to take it to a pro. He found a leaking gasket in the accelerator pump. going to rebuild the carb and hopefully that's all it needs. Will post back when I know for sure.
 

Brads 99

Recruit
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Aug 24, 2014
Messages
5
Thanks Rick, It is a constant issue. Ran it on an portable tank and electric pump with the same results. Rebuilding the carb and hope to have results in a few days. Anything outside of the motor/fuel system that comes to mind? We have some pretty good mechanical guys on it, but not a lot of boat experience.
 

Brads 99

Recruit
Joined
Aug 24, 2014
Messages
5
Okay, carb rebuilt and no real difference. I was told the coil or condenser could be the issue so I changed those as well. It runs pretty well from start up and good for a while depending on speed. 15 minutes wide open. Starts to sputter and tilting the trim up or backing off the throttle helps for a little while. Eventually, just stalls out for good. You can get to start up by sitting on the starter in neutral, but won't handle any load. Seems like it's flooding out, pops or flames shoot out of the carb. Any other suggestions on what to check next.
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
11,802
If you ran it on a portable tank that rules out a fuel problem like the vent or the anti siphon valve. Has it ever had an overheat? You might not know since you just bought it but if so, the exhaust flapper could have melted and might be blocking the exhaust system. Also Im wondering if the ignition coil could be breaking down when it gets hot. On a boat that old (been there done that lol) it could be so many things....
 
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