OMC 2.6L Sea drive outboards won't idle in salt water

tblentrprz · Mar 13, 2003

A friend has twin OMC 2.6Ls that fail to idle in salt water. No problem in fresh water. Off idle thru WOT no problem in salt water. Could it be some sort of electrolysis impacting ignition or just carb adjustment due to water density difference? Your feedback is greatly appreciated. Thank You.

JB · Mar 13, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

You seem to be talking about I/O engines. Movng this there. Good luck

Jack Shellac · Mar 13, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

Welcome to the forum. Wow, that's a new one and I can't wait to hear the answers. As a start, what year and what type of ignition are these engines?

Backlash · Mar 13, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

I can't wait to hear the answers either. Are you sure you're not just putting us on?????

Backlash

tblentrprz · Mar 13, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

I apologize, this post was accidently moved to the I/O forum. These are 1985 outboard engines. They are your typical OMC V6 motor with VRO. Not sure why OMC decided to only list displacement and not horsepower. Anyway, your thoughts are greatly appreciated. I want to make sure I'm prepared with the right tools, etc. before I drive 4 hours to the coast with this guy and work on this issue. I will surely report the solution. Thank You.

Boatist · Mar 13, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

Ok some one has to be first to guess. Here is my only idea. Salt water normally at sea level. At what elevation is it that these outboards run good. If it is a high elevation where they run good then at sea level must retard the timing a little and give a little more fuel. Second though is does motor warm up, thermostat working to keep motor about 150 degrees. Sea Water in Northern California about 54 degrees in July, lake in area can reach 85 degrees. That all I can think of.

tblentrprz · Mar 14, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

Thanks for the feedback. The fresh water is at 100' elevation. Not much change here in central east Texas. Water temp is basically the same. I will make sure the engines are reaching normal operating temp. Keep the thoughts coming. Thanks.

Dhadley · Mar 14, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

I cant wait to hear the outcome but to answer your question about the horsepower, Sea Drives were manufactured under OMC's "Drive Systems" division along with inboards, sterndrives etc. They were not assigned actual model years but rather "sales" designitaions. This is done so you dont end up with a 1995 boat with a 1994 motor. They also, like inboards and i/o's, did not get horsepower ratings but are very very similar to their outboard cousins. Let us know how your friend makes out. Good luck!

dick · Mar 14, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

This topic should be in the o/b forum.It's the moderators freakin out again ,and I can't wait to here this one answered.

Jack Shellac · Mar 14, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

Good answer, Boatist. Logical thinking. Here's my guess: My company spent a lot of money sending me off to troubleshooting courses and the most usseful question in a situation like this is "What Changed?" What comes to mind is that since the boat is being taken to a different place than usual, they may be buying gas at a different place and that the motors don't perform as well on whatever brand it is [alcohol content, whatever]. My suggestion would be to consider everything that is done differently when taking the boat to saltwater as opposed to freshwater and eliminate them by trial. I would start with the gas, since it's the most obvious. Just my 2 cents. Very interesting problem--please let us know how it turns out.

akriverrat · Mar 14, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

altitude?

omcmotorproblem · Mar 17, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

these are 1985 boat/motors originally a one owner,previous owner had trouble with health .boat/motors sat in the driveway 10 years .purchased by me. mechanic work before launch to replace fuel&oil pumps, fuel lines ,remove old gas ,carburetor rebuilds ,wiring ,and so on. engines idle forever at my office,elevation 500'.in fresh water no problem.engines at any speed other than idle no problem .I have tried the different gas at different locations no change in lack of performance! trouble begins the moment I start the engines at the coast.continues regardless of length of time running at a higher rpm ,(low rpm's)engines will alternately die ,regularly.

dick · Mar 17, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

Ok you said something here that does'nt sound right."engines idle forever at my office,elevation 500'.in fresh water no problem" By freash water do you have the boat in a lake or river or on are you running them in a bucket or off a hose at your office? Sorry if I miss read something here.The reason is O/B's requires backpreasure and to be in fwd gear to be properly set up.

omcmotorproblem · Mar 17, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

running at my office to purge after coast trips ,yes a water hose. Fresh water reference is a lake in my area.

Jack Shellac · Mar 17, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

Continuing to pursue the "What Changed? " concept and eliminating different fuels, the next thing that comes to mind is: You're going from the relatively dry air of the Hill Country to the humid, salt laden air of the coast. If your spark plug leads have aged and tend to leak spark, it's going to be much worse in the humid , salty air. If they are the originals, they're 18 years old and need to be replaced anyway. I think on my next trip, I'd go with all new leads and spark plug porcelean really clean [to prevent any possible flashover]. If this didn't cure it, would adjust idle up to keep the motors running and try it in fresh water when I got back. If it idles even faster in fresh water, that's a clue that's it's in your mixture[ I think the idle jets are fixed in this motor and can't be adjusted]. I think I'd also take a 6 gal can of the same gas used in freshwater to see if that helped, if the new leads give no improvement. OMC warns in the manual that these motors are sensitive to alcohol in the fuel and you may be getting more than usual without knowing it. Let us know how it turns out.

Dhadley · Mar 18, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

Good job Richard - thats what changes, the back pressure. It has nothing to do with fresh water. Its going to idle better on a hose as opposed to in the water no matter where he is. Good catch!

omcmotorproblem · Mar 18, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

new spark plugs and wires,yes.had'nt considered the alternate fuel supply. tank was flushed at the original mechanic, flushed being a key word ,not purged or sealed. considering the length of time set up and continuing carburetor problems (second mechanics continuos repair)could be a residual of the slimmy gas remnants from before? will also consider the possibility that my mechanics are not fluent in OMC's.carburetors could be adjusted to suit them and not omc standards.given the answers I have received I will seek out an OMC pro for final adj's after I remove the gas tank and either remake or have it cleaned and resealed. thanks. still does not explain the runs well in fresh water and poor in salt water.

JB · Mar 18, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

I just learned that these are SeaDrive outboards. Moving back to Outboard Questions.

Dhadley · Mar 18, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

JB - they've been Sea Drives all along - at least since the mid 1980's! Lol! Just kidding although I'm not good at hitting a moving target like this. Good thing this is fun, huh?

ICEMAN · Mar 19, 2003

Re: OMC 2.6L Sea drive outboards won't idle in salt water

HI, Do you run these motors all the way down in the trim range? When you get to the salt water, try tilting the motors up a little and see if that helps. Sometimes these motors have a tendency to load up (run rich) if titled all the way down.

OMC 2.6L Sea drive outboards won't idle in salt water

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