View Full Version : OMC shifting problems

05-11-2004, 10:43 PM
I have a 1986 OMC 4.3 litre 2brl sterndrive.
Having difficulty shifting from forward to neutral and to reverse. It shifts fine once in
neutral to forward. It took almost two hands to
get neutral yesterday! Whatever achieves smooth
shifting in this sterndrive must be faulty.
Any suggestions would be greatly appreciated.

05-12-2004, 10:15 AM
"Sounds like you have an out of adjustment cable linkage. Go here and good luck.

http://www.hastings.org/~stuart/cobra/ ("")"

J Donlon
05-12-2004, 12:10 PM
Cobra drives have an inherant problem with shifting... it requires very very low idle to shift and if that low idle is not acheived it is extremely hard to shift. Mine has actually stuck in forward. There is something called an esa (electronic shift arrestor)as the shift cable moves it opens and close rocker switches that momentarily stop the spark and slows the idle down allowing the gears to move. It will not however slow the engine enough if it is idling above about 800rpm. Very common and costly mistake is to raise the idle of a rough idleing cobra to make it run better! In any case if you problem is not in the actual shift handle my first place to look would be the tach.. if that is idling below 800 (and 800 is still a bit much) test the ESA switches. An out of adjustment cable usually causes the drive to engage only forward or only reverse.

05-12-2004, 09:49 PM
excellent advice!

Thanks alot.

05-12-2004, 11:15 PM
" I seem to be having a similar problem except mine shifts into and outta gears well but my trouble is when I come out of gear, it kills the engine, doesn't matter wether its fwd or rev. I talked to a merc. dealer and he said almost without hesitation it was my lower shift cable, and not my switches which I have two of them mounted on the assymbly. could he be right or would I be better off trying to adjust them myself? I thought of disconnecting the lower cable and running it through fwd and rev. to see if I can duplicate the problem.

any advice?? "

Andy Miller
05-14-2004, 11:39 AM
I had similar problems on a 1996 4.3 mercruiser. It stalls out when shifting into either gear and was sometimes harder to shift I think moreso into reverse and both were intermitant. On the throttle cable assembly at the carb there is two cables one hooks to a lever and at the lever is a lock screw. Looking at it the lever is slotted and the point it can be positioned can be moved abotu 3/4" up or down. The lock scew had come loose and allows the cable to move up or down it actually looked like it was supposed to slide up and down in this slotted area. But it is supposed to be secure this moves the lever that turns the kill switch on and off momentarily while working the gear shifter and throttle in and out of gear. After only a minute or two of adjutments it works flawlessly. I had raised the engien Rpms up to around 800 to help keep it from stalling so bad after restting it to 600RPMS it is like new. It took two people to actually see how it all works as one has to work the throttle while you watch it all work.

05-23-2004, 10:15 AM
" Not to through a monkeywrench into the subject, but I have a 1986 fourwinns with stearing problems. Hard to shift at low rpm's. Checked cables and all seem to be fine, also put some greese at the stearing mech. under the dash. Email me with any sugestions, thanks. "

05-15-2006, 11:39 AM
"On the OMC; the hard shift out of gear is almost definite ESA trouble. If it's only hard out of foreward not reverse then it may be the adjustment on either the over-stroke switch or the lower cable. If it's hard outa both gears it may be a bad switch or a failed ESA box. If it's ok sometimes then not other times, it's probably just a switch. Mercs use a different system and if the lower shift cable is hard to move it can cause a stall. The merc. system completely cuts ignition 'till the cable moves into gear whereas the OMC limits RPM without completly cutting power. Regardless of what the idle RPM adjustment is set at, the OMC ESA will slow the RPM, and the Merc. will stall if held engaged."

05-21-2006, 02:32 PM
"I'm having the same problem with shifting out of gear with my 89 OMC Cobra. A shop replaced the ESA with one that had a different connector plug that kept the overide from working, making the engine loose power whenever the throttle was moved. I corrected by rewiring the ESA. All was fine until I installed a 4 blade prop. Now it is sticking again and I believe it is due to the additional torque required to turn the 4 blade prop at low speed. Next step is to minimize the idle speed. Manual calls for 500 to 600 rpm. I will try for 500."