transome

Status
Not open for further replies.

roneli

Cadet
Joined
Jul 18, 2015
Messages
8
Hi
I have a Bayliner with OMC drive and is going to switch to Alpha one gen 2, do you know what i need to do in the back wall of the boat to get it to fit?


Ronny Eliassen
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,286
Whole new inner and outer transom shield and pattern as far as I know. Also your engine will have an influence on what drive you need too...worst case.
 

kpg7121

Petty Officer 2nd Class
Joined
Aug 25, 2018
Messages
174
Hi
I have a Bayliner with OMC drive and is going to switch to Alpha one gen 2, do you know what i need to do in the back wall of the boat to get it to fit?


Ronny Eliassen
SEI Sterndrives has a conversion kit which you use to convert your Cobra over to an essentially Merc drive system. You purchase the drive which is an aftermarket Mercruiser & the conversion kit. No need to do any transom work because with the conversion kit it's bolt on. I believe a new shift cable is included in that kit along with whatever else you need to change over. You may have to change your helm shifter as the shift system is the same as Merc. Last time I checked I think the change over will run you about $1800, if you do the wrenching. What year Bayliner are we talking about because I'm assuming it has the Cobra drive.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,470
Hi
I have a Bayliner with OMC drive and is going to switch to Alpha one gen 2, do you know what i need to do in the back wall of the boat to get it to fit?


Ronny Eliassen

Ayuh,...... Welcome Aboard,...... Stringer,..?? or Cobra drive,..??
 

roffey

Commander
Joined
Nov 22, 2012
Messages
2,187
Maybe a stupid question here but here goes. Why not convert it to outboard? Would it not be cheaper and easer. I would think changing from OMC to Merc will require everything from the motor mounts to the prop?
 

kpg7121

Petty Officer 2nd Class
Joined
Aug 25, 2018
Messages
174
Maybe a stupid question here but here goes. Why not convert it to outboard? Would it not be cheaper and easer. I would think changing from OMC to Merc will require everything from the motor mounts to the prop?
Changing over from a sterndrive to OB would require major transom work. That project is not for a novice. With the SEI conversion that's not neccesary. All he has to do is purchase the drive, the kit which includes a new bell housing, shift cable, etc. For less then $2k he can get rid of the OMC & have essentially a Mercruiser & not have to deal with a drive system that is for all intents & purposes obsolete.I had planned on going that route myself until I discovered my transom was rotted so I parted the boat out.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
47,309
first, we nee to know what OMC the OP has. this is required prior to any answer.

if its a cobra drive, simply unbolt everything OMC from the helm to the prop, throw away and bolt in everything mercruiser or late model VP (you may need to drill two holes). OMC adopted the mercruiser key-hole for the cobra

if its a stringer, you need to tear out the interior of the boat, remove the deck, rebuild the stringers, bulkheads and transom for a transom mount, then foam and add the deck back in. this is because you can drive a buick thru the hole in the transom for a stringer drive and no structure was needed on the transom for a stringer drive

to go to an OB, more structure needs to be added than swapping from a stringer, knee braces are needed to tie the transom into more of the boat because the load path is completely different.

so roneli what do you have now? What vintage OMC drive do you have? without that information, none of us can answer how to move forward, and if anyone has a different answer than Bondo or I you are speculating.
 

roneli

Cadet
Joined
Jul 18, 2015
Messages
8
I had a cobra drive.Have a merc 4,3 EFI and a alpha 1 gen 2 drive on the boat.The guy who mounted this have done something wrong,backplate and some transome parts is still OMC.Seems like i cant trim the drive down enough.
 
Status
Not open for further replies.
Top