PDA

View Full Version : King Cobra Outdrive needed



travisgoff
04-29-2007, 10:15 PM
I had a drive decide to chew some gears up and I had to replace it, unfortunately, I replaced it with a small block V8 instead of a big block. Now one engine runs about 900rpm higher and I lost about 20+mph top end because of the different gearing.

I am not really sure how to fix it except for buying the correct drive. So if anyone has one that they can spare or would like to get rid of, please let me know. I think I will probably try and put new drives on it with my tax return if I can find someplace that can do it without killing me in cost. It might be easier to sell the boat and get one with a single engine/drive at the rate I am going.

Any help would be appreciated.

Travis Goff

travisgoff@comcast.net
757 620 2194 (cell)

joel3078
04-30-2007, 08:57 AM
There was 3 ebay sales last month - none sold
1 complete unit upper & lower
1 lower with gears/shafts
1 lower case only
Just type omc, king cobra, cobra, etc. into ebay and good luck. They are hard to come buy and are expensive.
If mine ever craps out, I am happy to know that Merc fits in the same transome hole. Current Volvo SX drive probably does also. I think 3-5 grand is the magic number to have do the swap depending on how much work you can do yourself.

wrasse
04-30-2007, 09:09 AM
Sent you an email.

I have a spare brand new complete king cobra lower with 1:5 ratio. Also have used upper but I'll have to see if I have the plastic covers for it.

mysterywrasse@hotmail.com

Alwayz Sumthin
04-30-2007, 09:56 AM
If mine ever craps out, I am happy to know that Merc fits in the same transome hole.

Joel,
Have you ever done that or know of it being done? I just smoked my OMC King Cobra drive last night and I have always wanted to put in a Bravo but figured it would be alot of work. Any info you have would be great.

wrasse
04-30-2007, 12:02 PM
It involves a few things, getting raw water crank pump, removing the shift interrupter unit, some belts, getting a bravo or volvo transom assembly and drive. Requires removal of engine so it's not a simple bolt off and on. I looked into going volvo SX route which I think is stronger than a regular bravo and it involves basically the same steps. New crank driven water pump, transom assembly, and complete drive. Then someone to R&R the motor and rig the sterndrive assembly. I found that most shops felt uncomfortable approaching this type of work and I had to do the research myself and tell them it's doable. It ended up being too much of a hassle so I just found a replacement King cobra to bolt on and go which is what I ended up doing after my original drive blew up after filling up with water due to dipstick cap sabotage. Mine actually ran for several hours full of water before blowing! Kings are a strong drive for sure.

Joel,
Have you ever done that or know of it being done? I just smoked my OMC King Cobra drive last night and I have always wanted to put in a Bravo but figured it would be alot of work. Any info you have would be great.

Alwayz Sumthin
04-30-2007, 12:17 PM
wrasse,
Good info, I had figured all of that to be included, I was concerned about the transom if fiberglass was needed and all of the unexpected stuff that occurs in a new set up. I recently put a new powerplant in the boat last year from Teague Custom and have been babying the outdrive till last night. I had thought the King Cobra was strong enough to hold 590 hp but I was wrong.
Thanks again for the info. I will attach a pic of the new powerplant.
Scott

http://www.donzi.net/forums/attachment.php?attachmentid=23562&d=1156971753

Alwayz Sumthin
04-30-2007, 12:25 PM
Thanks for the info, I had figured all of that was involved my concern was about the transom and if fiberglass work was needed to make the swap. I had put in a new powerplant last year from Teague Custom and figured if I babyed the lower unit it would last a while. Nope not the case 590hp on a OMC King Cobra just doesn't work.

wrasse
04-30-2007, 01:22 PM
No fiberglass work as far as I know. Same size hole. You probably need to go with bravo XR for the power and the size of the boat you're running especially if it's a single although I've seen kings survive 600hp on similar heavy boats. Luck I guess!


Thanks for the info, I had figured all of that was involved my concern was about the transom and if fiberglass work was needed to make the swap. I had put in a new powerplant last year from Teague Custom and figured if I babyed the lower unit it would last a while. Nope not the case 590hp on a OMC King Cobra just doesn't work.

Dr. Dan
04-30-2007, 02:59 PM
Thanks for the info, I had figured all of that was involved my concern was about the transom and if fiberglass work was needed to make the swap. I had put in a new powerplant last year from Teague Custom and figured if I babyed the lower unit it would last a while. Nope not the case 590hp on a OMC King Cobra just doesn't work.

I have what's been called a "Healthy" HP500 EFI, and I have not had any issues.... I am only pushing a 22...but never had any drive issues. I have heard they were good for up to about 650 Ponies if you are not launching and reentering the water all of the time?

I guess my situation is the opposite of what's been discussed above, with a Merc Engine and King Drive? I omitted the King Water Pump and it runs like a Bravo on Steroids.... never had any cooling issues either?

Doc of Eventual Drive Replacement :smash:

MOP
04-30-2007, 04:01 PM
Don't expect a Bravo to be stronger NOT, maybe an XR but not a standard X. Running that kind of power they not only need very good oil but need to have the rolling torque checked every season, as soon as the rolling torque drops under spec they need to be torn down and re shimmed. Most OMC & Merc guys just run them until they blow!!

Alwayz Sumthin
05-01-2007, 04:12 PM
Thanks guys for all your input, I am going to the repair shop today to find out just what kind of damage was done. Hopefully the ins will cover it all. :wink:

joel3078
05-01-2007, 04:25 PM
Joel,
Have you ever done that or know of it being done? I just smoked my OMC King Cobra drive last night and I have always wanted to put in a Bravo but figured it would be alot of work. Any info you have would be great.

Nope never did it. My KC is still working great. Put all new seals, bellows, impeller, etc. in it last fall. U-joint and gimble were replaced a few years ago. The threads above this pretty much some up the work to do however.