OMC I/O 5.8L won't stay running

[bcsides2007]

I've looked through the forums and have had luck in the past finding info for my boat and engine, but can't seem to find out a solution to my newest problem. I have a OMC Cobra I/O 5.8L engine. It is on my 1991 19.7' Phantom Cuddy Cabin Boat. The problem is it won't stay running. It's starts up like normal and will seems to stay running as long as I don't give it too much throttle. It usually cuts off pretty quickly when I get it up above 1000rpm on the Tachometer on the dash. It was working fine a couple months ago, but I can't seem to figure out what is going on. Another new thing I've noticed is sometimes when switching from Forward to Reverse is a grinding sound. It only does that every now and then. If anyone has any advice on what I should look for then I'd appreciate it. Thanks.

 

[Don S]

Re: OMC I/O 5.8L won't stay running

Have you checked the fuel filter for water? I don't mean just replace it and try again. Remove the old filter, dump it in a clear container and see if there is water in it. If not, install a new filter anyway. Never reuse one that has been emptied. Any dirt could contaminate the clean side and allow it to get into the carb.

 

[bcsides2007]

Re: OMC I/O 5.8L won't stay running

Figure I'd post what I found out recently. Instead of working on it myself I took it to the Marina Shop. They started it right up in the shop and told me they didn't see any problem with it. Then when I told them that it was cutting out on me on the water, well...they had to take it to the water. What they came back with is that it started up fine, idled fine, and only died out when shifted into gear. They just said they had to power shift it to get it to go, but otherwise it ran just fine. Got it up to 40+ mph. However, they did say they noticed water was leaking between the head and the block. Probably a gasket. I took it out after picking it up and got her going good for over an hour. I kept checking for the water they were talking about, but nothing. I really don't know whether to believe they saw water or just believe the fact that I can't see any. Well, they recommended that it is probably time for me to upgrade to a newer model. Seriously, I don't know if they were just trying to sell me a boat from the lot or really did see the water leak at the block. Hopefully in the meantime it won't hurt to run around on it considering I saw no evidence of water. As for the safety relay that was the cause of me taking my boat in to them, well, they said it just needed adjustment.

 

[danond]

Re: OMC I/O 5.8L won't stay running

So they took it out, pinned the throttle, beat it into gear, said it has a random leak, then gave it back? Nice work.

You're right. They're trying to sell you a new boat. Especially the part where they said "you should buy a new boat" instead of fixing the problem(s).

I'd take it elsewhere from then on.