Difficulty Shifting to Neutral with 1995 OMC Cobra SX

[Horigan]

Just purchased my first boat; 1995 Chris Craft Concept 21 with an OMC 5.0 EFI motor with Cobra SX stern drive. Overall in excellent shape. One area I'd like to improve is shifting from FWD to Neutral. When the engine is running the transition is a little stiff. Engine off the transition is smooth, as is reverse to neutral. My research indicates this could be associated with a shift interrupt system, but I'm not sure how that system is implemented in this later year OMC system that is Volvo based. Is this likely just a shift cable adjustment issue, or is there an ESA type system I should check?

 

[HT32BSX115]

Just purchased my first boat; 1995 Chris Craft Concept 21 with an OMC 5.0 EFI motor with Cobra SX stern drive. Overall in excellent shape. One area I'd like to improve is shifting from FWD to Neutral. When the engine is running the transition is a little stiff. Engine off the transition is smooth, as is reverse to neutral. My research indicates this could be associated with a shift interrupt system, but I'm not sure how that system is implemented in this later year OMC system that is Volvo based. Is this likely just a shift cable adjustment issue, or is there an ESA type system I should check?

Howdy,

Welcome aboard.

It might help if you post your actual model number.

A 1995 model year boat could have any one of the following engine/drive models installed.
502APHUB 1995
502APHUE 1995
50FAPHUB 1995
50FAPHUE 1995

502ACPMDA 1994
502AGPMDA 1994
50FACPMDA 1994
50FACPMDM 1994
50FAGPMDA 1994
50FAGPMDM 1994

Since yours is an EFI model, it narrows it down a bit but it does help when looking at the parts illustrations.
http://epc.brp.com/

If I am not mistaken, the cone clutch drives did not have ignition interrupt...... and certainly didn't have an ESA module like the older dog-clutch drives. (neither does the Mercruiser Bravo cone-clutch system) Although there may be ECM provided ignition interrupt, looking at the engine electrical diagram for the carbureted models, there appears to be no ignition interrupt of any kind connected.

In any case, if the drive shifts easily out of REV, but not FWD, I would expect the shift cable to be mis-adjusted, sticking or failing internally.

If you do not have an OEM OMC or Volvo Penta service manual, now would be a good time to get one.

While you're looking you can use http://boatinfo.no/lib/omc/manuals/1986-1998omcmanual.html#/0 But it's not as good as the OEM manuals.

Regards,


Rick

 

[Horigan]

Thanks Rick. The part number is 50FAPHUE. Thanks for the part number site. That's just what I've been looking for.

I've been using the boatinfo site for maintenance and troubleshooting, as well as the two aftermarket service manuals that came with the boat. I'll find the OEM manual on eBay, as I've seen them there before.

I'll review the parts site to see if there is any kind of ignition interruption system, but I don't think there is one either.

Thanks for the response.

Rich

 

[bruceb58]

No interrupt system on your drive.

Disconnect the cable at the drive and see if it is still hard to move shift lever. If it is, you need a new cable

 

[Horigan]

I'll try that. Thanks. Given that the shifting is butter smooth with the engine off had me wondering about an interrupt system. Will check with it disconnected.

Rich

 

[bruceb58]

I'll try that. Thanks. Given that the shifting is butter smooth....

Well that is interesting. Check your gear oil level. If it's too high, that can also cause hard shifting.

 

[HT32BSX115]

Well that is interesting. Check your gear oil level. If it's too high, that can also cause hard shifting.

:boink:Bravo's never have that problem!!

I'll try that. Thanks. Given that the shifting is butter smooth with the engine off had me wondering about an interrupt system. Will check with it disconnected.

Another thing you might try is shifting the drive using the shift cable once it's disconnected. Do it on the trailer with the engine idling.

With the engine off, same In both directions? REV-->N and FWD-->N ??

 

[bruceb58]

:boink:Bravo's never have that problem!!

I actually never experienced it myself...something DonS mentioned!

 

[HT32BSX115]

I actually never experienced it myself...something DonS mentioned!

I know very little about cone-clutch SX's.....but I just couldn't resist!

 

[Horigan]

Circling back on this topic to share what I've found. With the cable disconnected at the drive, the mechanism operates smoothly in and out of both gears. I was surprised how much wear and slop there was in the linkage mechanism, but it still seems to work. Even with the motor running out of the water (with muffs installed) it is still butter smooth coming out of FWD. Only when the boat is in the water is the stiffness present going from FWD to neutral. It must be a wear issue with the FWD cone clutch that only presents itself when under load. Interesting... Again, coming out of REV is smooth.

I did check the fluid level and it was over-filled by a couple of tablespoons, but correcting that had no effect.

The issue is minor and isn't worth tearing in to the drive. It looks like the shift linkage components are still available, so I'll probably rebuild that to eliminate the slop, then re-adjust the cable. Maybe that will help.