looking at boat with 1991 5.7 l cobra 350...

gbeltran

Petty Officer 1st Class
Joined
Jul 12, 2009
Messages
283
Re: looking at boat with 1991 5.7 l cobra 350...

I'd keep looking. One, it's worn. Two, it's a Cobra. It's easy to get emotional when looking at boats, especially if you think they it's a good deal despite the fact it needs work.
 

Idlespeedonly

Senior Chief Petty Officer
Joined
Jun 30, 2011
Messages
779
Re: looking at boat with 1991 5.7 l cobra 350...

You need to have somebody that is very familiar with inboards look at it. For the right price it may be a good deal.
 

blenkch

Cadet
Joined
Sep 11, 2011
Messages
6
Re: looking at boat with 1991 5.7 l cobra 350...

Thanks for info...went into more detail and found 6 cylinders at 120-125 ,one at 100 and one at 50!
Could it be just a head gasket as 2 bad ones are adjacent?
What is worse case scenario?
Price was too good to be true.
Test drive was smooth...is it possible seller didnt know (though he didnt seem surprised).
Are cobra no good?
Thanks
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: looking at boat with 1991 5.7 l cobra 350...

Run away.
Dead engine, and who knows what else.
OMC also went out of business in 98
 

gbeltran

Petty Officer 1st Class
Joined
Jul 12, 2009
Messages
283
Re: looking at boat with 1991 5.7 l cobra 350...

Maintained as they should be I don't think the Cobra is a bad unit. Problem is OMC has been gone for quite some time. Finding parts is not always easy, they can be had but they are usually not at the local marina. Finding someone who knows how to properly work on one if you're not the mechanical type can be challenging. Could be a lot of things, bad rings, bad valves, and yes, bad head gasket. But even the good cylinders are low. Good news is GM engines are easy to come by and even a rebuilt marine version from someplace like Rapido wont break the bank. My last boat had a Cobra drive, and while the drive didn't give me any issues I wouldn't buy another simply for the reasons listed.
 

sethjon

Senior Chief Petty Officer
Joined
Jun 8, 2010
Messages
692
Re: looking at boat with 1991 5.7 l cobra 350...

compression on one side 120-125 and other @ 100.
Should I be worried

Anyone who tells you that Cobras aren't any good doesn't have real knowledge of what they speak. Properly maintained they are great. In this case however,, with one cylinder at only 50 I'd look else where. sounds like it will need a lot of work and why the spend the money on a repair. Get somethng already in good shape.
 
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