1994 454 king cobra cone clutch shifting problems

[cabe227]

Well as the title says im having issues with shifting. My mechanic just had the engine out of the boat to replace a cracked head. When I got the boat back everything seemed fine. For about 2 miles. I shifted into neutral to slow down and then back to fwd but nothing but revs. I tried again and again and it would catch a little then pop back to neutral. The boat shifted completely fine before the engine pull and the mechanic admitted that he didnt do much OMC work... I brought the boat back and he said he double checked the shift linkage and swears its good and that he did some reading and says my clutch is slipping and wants nothing to do with the repair. I am a capable aircraft mechanic with a turbine background so if there is anything I can check myself I will. Could he maybe have filled the out drive wrong? Or with the wrong fluid? Can I still find clutch parts? First boat and first expereance with OMC. I have done some searching and wound up with only totally rebuilt O\Ds.

 

[HT32BSX115]

Re: 1994 454 king cobra cone clutch shifting problems

Well as the title says im having issues with shifting. My mechanic just had the engine out of the boat to replace a cracked head. When I got the boat back everything seemed fine. For about 2 miles. I shifted into neutral to slow down and then back to fwd but nothing but revs. I tried again and again and it would catch a little then pop back to neutral. The boat shifted completely fine before the engine pull and the mechanic admitted that he didnt do much OMC work... I brought the boat back and he said he double checked the shift linkage and swears its good and that he did some reading and says my clutch is slipping and wants nothing to do with the repair. I am a capable aircraft mechanic with a turbine background so if there is anything I can check myself I will. Could he maybe have filled the out drive wrong? Or with the wrong fluid? Can I still find clutch parts? First boat and first expereance with OMC. I have done some searching and wound up with only totally rebuilt O\Ds.

Howdy,

Welcome aboard!

You can find part numbers at BRP -- Parts Catalogs

You have to have your engine model number to find them. It should look something like the following if it's a 1994:

744DCPMDA 1994
744DCPMDM 1994
744DDPMDA 1994
744DDPMDM 1994
744DGPMDA 1994
744DGPMDM 1994
744DJPMDA 1994
744DJPMDM 1994

OR, if a 1993

744CPEJVB 1993
744DPEJVB 1993
744DPPJVB 1993

Understand that you CANNOT BUY the parts there. You only find model numbers and parts number break-outs and pictorials etc. You'll have to find an OMC/Volvo Penta trailer someplace. And remember, just because the part is listed anyplace doesn't mean it's still available.

I believe that drive is a Volvo SX so most parts should still be available...... Right around 1994/1995 OMC started using Volvo SX drives......

There's not a LOT you can do though. To replace a cone clutch assy, you have to disassemble the drive. To reassemble, you need some rather specialized tools to set it back up. OMC and Volvo techs go to school to learn to work on them.

If it were mine, I would consider replacing the drive with a Volvo Penta DPS .......

I am not absolutely sure of the exact model DP drive that bolts on that transom mount, but if you have to do a drive rebuild, NOW would be the time to make the change. The performance improvement alone is worth it.


Cheers,


Rick

 

[cabe227]

Re: 1994 454 king cobra cone clutch shifting problems

Thanks for the response rick. I ran the block and sterndrive p/ns when I bought the boat and it is indeed a 93 cone clutch king.. I am really wondering if it could be something stupid simple like the mechanic filling the drive wrong or using a full synthetic or something like that. Ive only had the thing on the water three times. The first time the day I bought it and I ran 60 gallons of fuel through her over the day stop and go. I docked several times and smooth shifting the whole time (with one finger). The second time I had watervapor get into the distributor and ended up limping back to shore misfireing (no shifting problems even then) and had one of the cylinders detonate and cup a valve. Mech took the engine out to work the heads and now I have shifting problems the 3rd time on the water. He says the shift cables are adjusted right but he doesnt know squat about later model OMCs. Any advise? The boat is in great shape but only worth about 10k running properly.

 

[HT32BSX115]

Re: 1994 454 king cobra cone clutch shifting problems

I am really wondering if it could be something stupid simple like the mechanic filling the drive wrong or using a full synthetic or something like that.

Full synthetic oil is recommended for all cone clutch drives. You can use Mercury HP, Mobil-1, Am$oil Marine, Royal Purple, You name it etc.

Mech took the engine out to work the heads and now I have shifting problems the 3rd time on the water. He says the shift cables are adjusted right but he doesnt know squat about later model OMCs. Any advise? The boat is in great shape but only worth about 10k running properly.

Well, the mechanic HAD to remove the drive to get the engine out. He also had to readjust everything(or should have) upon re-installation. If the shift cables aren't adjusted correctly, I think it might be on him.

I am not entirely sure you have a Volvo SX now. You appear to have the infamous "interim OMC Cobra Cone-clutch" drive that has the raw water impeller on the back of the drive that is NLA. Many people installed a Volvo engine mounted raw water pump on those because they couldn't find impellers any more.

Do you have an engine driven raw water pump installed on your engine?

Also, do you have electronic fuel injection AND electronic spark control/IGN?

The boat is in great shape but only worth about 10k running properly.

I am sorry to say that you may have a completely worthless engine and drive that is not worth spending a lot of time and money on......This is also why there's not very many marine mechanics that will even want to try to fix it for you......There was 3 or 4 years from 1990 to approx 1994 where OMC had a drive that was neither earlier "dog-clutch" nor Volvo SX (which are both still supported) .......


It's possible that the forward cone clutch simply failed. Did it go into reverse ok?

If you look at the parts breakout above, #16 (both of them) are your forward and reverse clutch (halves) and #37 is the "other" half. If one of them or one side of #37 is severely worn/damaged, they would be need to be replaced.

That's literally a complete "rebuild" since you wouldn't want to put the drive back together with out resetting the bearing preloads, new seals, and possibly new bearings, shims, etc where needed etc.......

I found #37 for approx $340 and 16 is part of a complete gear set. That won't be cheap......


If the engine still has the EFI and electronic Sptifire ignition, you can of course, go to a carburetor and a regular distributor (if it isn't already)

You can also do what I did and swap the entire mess for a Mercruiser or Volvo engine and drive.


I know the above doesn't sound very inviting. Sorry about that.


Rick

 

[cabe227]

Re: 1994 454 king cobra cone clutch shifting problems

Not inviting at all but thats what I get I guess. All of the spitfire ignition systemIis gone and I have all MSD set up now. 6AL box to blaster 2 coil. The engine is a 454 H.O. with the big holley 4brl carb on top. I am out of town now but when I pick it up I am going to ask about the outdrive oil and the shift cable adjustments. Does this drive have the lower shift cable that the dog clutch kings had going bad all the time? Oh and the water pump is still located in the drive. It had a new impeller put in this winter (80 bucks)

 

[HT32BSX115]

Re: 1994 454 king cobra cone clutch shifting problems

Not inviting at all but thats what I get I guess. All of the spitfire ignition systemIis gone and I have all MSD set up now. 6AL box to blaster 2 coil. The engine is a 454 H.O. with the big holley 4brl carb on top. I am out of town now but when I pick it up I am going to ask about the outdrive oil and the shift cable adjustments. Does this drive have the lower shift cable that the dog clutch kings had going bad all the time? Oh and the water pump is still located in the drive. It had a new impeller put in this winter (80 bucks)

It does have a shift "cable" but it is quite a bit different from the Dog's. There's no where near the problems with cone clutch OMC drives as there was with the Dog-clutch drives.

You're lucky if you can find an impeller for $80. That impeller, when you can find it, is whatever someone wants to charge for it. No one is making them. Be careful with it....... it's a "show-stopper"

The only other choice unless you can find new (old-stock) impellers is to install a Volvo or other engine driven pump.

Sounds like you're "covered" on the engine. Someone already replaced the NLA ignition. consider yourself lucky you don't EFI!

If you REALLY like the boat, you might consider finding a Volvo DP drive. You'll have to speak to a Volvo dealer about whether it will bolt to that transom and gimbal mount. The REAL expert here passed away in July. We all are going to miss him!


As much as I think you could either rebuild your current drive or replace it with a similar drive, I would strongly suggest that you switch. There are many internal parts in that Interim drive that simply do not exist and no one is making them since OMC didn't make them for very long before switching to the Volvo Penta SX.....OMC sold the entire stern-drive business to Volvo before going out of business in 1998 or so.

 

[cabe227]

Re: 1994 454 king cobra cone clutch shifting problems

Thanks again for all the info. I have been reading up on these things since I bought the boat in april and really wanted to try the DPS conversion if everything went to crap. I did speak with all american drive service and the tech told me that if it was indeed the cones that it would have happened gradually. Not immediatly after the engine and drive were reinstalled. They do have a complete parts kit for my drive now but he thought it sounded like mal-adjustment. I am glad I took it right back to the mechanic and did not try to use it anymore which may equal gears after a bit. Anyone know of a good OMC mech. Near eastern PA?

 

[HT32BSX115]

Re: 1994 454 king cobra cone clutch shifting problems

They do have a complete parts kit for my drive now but he thought it sounded like mal-adjustment. I am glad I took it right back to the mechanic and did not try to use it anymore which may equal gears after a bit. Anyone know of a good OMC mech. Near eastern PA?

Yeah. I don't think cone clutches fail suddenly either. I would lean to an adjustment. You can see from the pictorial that shifting must happen positively into either gear. Also, the drive must be "turning" when you shift it. Don't shift it with the engine shut down.

Damage (to gears) won't happen per se' with incomplete/slow shifting like a dog-clutch's. There's no dogs.

But since half of the "cone" is PART of each (FWD/REV) gear it's the inside "cone" (#16) and the shaft-cone (#37) that can "wear" quickly if it's slipping.

You don't want them slipping. That's why you want positive shifts (at the lowest possible idle speed) to minimize metal to metal sliding.

I have been reading up on these things since I bought the boat in april and really wanted to try the DPS conversion if everything went to crap.

The goal of going to a DP drive is a good one. You will not believe the performance difference!


My 1987 21ft Four Winns Liberator was always a real dog out of the hole even when it was new. My brother bought it new with the (340hp) 460 /King Cobra

Once on-plane, it was pretty fast (60mph)............... but he ran it at 5000 RPM (well above the max recommended 4600....which is probably why it had a flat cam when I got it!!)

When I installed the similarly powered (330hp) 454 + Bravo III, the top speed suffered a tad..... (57 MPH at 4600 RPM, rev limited at 4700)

But the hole-shot! It comes out of the hole like a ROCKET now! Acceleration is just off the chart by comparison. And of course the idle speed manoeuvring is far better etc......

So get your drive adjusted correctly and start looking for DPS drive for the future change!

 

[Howard Sterndrive]

Re: 1994 454 king cobra cone clutch shifting problems

You can find part numbers at BRP -- Parts Catalogs

Understand that you CANNOT BUY the parts there. You only find model numbers and parts number break-outs and pictorials etc. You'll have to find an OMC/Volvo Penta trailer someplace.

If you go to shop.evinrude.com, you'll be able to access the same pages, but with prices and availability of parts.

 

[HT32BSX115]

Re: 1994 454 king cobra cone clutch shifting problems

You'll have to find an OMC/Volvo Penta trailer someplace.

Haw! I meant RETAILER!!! (like shop.evinrude.com or equivalent):facepalm::laugh:

 

[cabe227]

Re: 1994 454 king cobra cone clutch shifting problems

Thanks again for the pointers. I am actually really happy with the performance of this boat. Its got a 19p renegade prop and at 4400-4500 rpm I was crusing a cool 69 on both my lorance gps and my garmin. When I ease out of the throttle I can keep her up on plane at 30 with out touching the trim. Even when I had no compression one cylinder 1 she still hit 63 (before I realized it wasnt just a little water in the fuel). The previous owner had put a pretty nice cam in it when the owner before him sold it with a cracked block. Is there any manuals for my drive on here so I can check the adjustment of this shift cable infront of my mechanic?? Could possibly save me some money

 

[cabe227]

Re: 1994 454 king cobra cone clutch shifting problems

Or was it a 21p prop? Ill check when I get home

 

[HT32BSX115]

Re: 1994 454 king cobra cone clutch shifting problems

There are manuals out there that you can buy. They're dependant on your actual model number though.
Here's an online one to tide you over though Boatinfo - OMC 1986-1998 Service Manual

Its got a 19p renegade prop and at 4400-4500 rpm I was crusing a cool 69 on both my lorance gps and my garmin

Something is amiss there because your theoretical (NO-SLIP) speed with a 1.41:1 ratio could only be 57 mph with a 19p and 63 with a 21p prop.
Prop Slip Calculator

I would say your GPS is probably NOT wrong so the prop pitch could be off AND/or the TACH is off.

With a 1.41:1 drive and 21p, it would take 5500 RPM to give you close to 70mph with 15% slip....... (15% is typical for a single prop and a runabout boat)

I don't think they used a drive ratio and higher than 1.40:1 in any of the Cobras.....

Tachometers are frequently way off at higher RPM.....

 

[cabe227]

Re: 1994 454 king cobra cone clutch shifting problems

Not sure the drive ratio... the tach needle does bounce quite a bit and the 6AL box has a 6000rpm chip in it...just havent changed it to the proper 4800 or so yet. The speedo also pegs out all the way around past 50 mph at the 4:30 position to the 0 stop at 7:30. The Later model liberators in my opinion are bad *** little boats. It was between the one I bought and a late model pachanga

 

[HT32BSX115]

Re: 1994 454 king cobra cone clutch shifting problems

Yeah, This lib is a bit scary when you go fast. It tends to chine-walk if you hit a wake at an oblique angle at 50 and above.


A guy over on Offshoreonly.com told he put a stroked Ford 460 in his and with the King Cobra and a really "tall" prop it would "Bury the speedometer at 80 mph" (his words!)

I wouldn't want to be going 80 MPH in this Lib!


I have done it in a pickle-fork hydro with a BBC and it was scary enough!

I believe you have a 1.41:1 ratio drive. So you would have to be turning at least 5500 to get that speed with a 21p prop......

Not out of the realm of possibility at all!

btw, that's no-mans-land for these drives. They weren't designed to turn more than about 5000. If you intend to keep doing it, make sure you use synthetic oil and maybe put a shower on it!