1988 V4 OMC - Does Not Want To Idle

[Solittle]

This engine is on the OMC Sea Drive (also 1988). Runs fine once you get it in forward gear and above 1200 rpm. Put it in neutral so as can shift back and forth into reverse when docking and it will quit. This is a real bit#$ when in a tight spot with a bunch of wind.<br /><br />Other info - Idles at 12-1300 running with a muff in the driveway. Idles when in the water and warm at 6-700 rpm. Runs smooth and has expected power when in forward. I put in a new set of center fire plugs as the old were "oil wet" and had a small amount of crud. New plugs did not help.<br /><br />The Sea Drive may play a part in this as the linkage on the engine for shift and throttle have a lot of play/slop due to the Sea Drive design.<br /><br />Also I have not been able to get a real hard primer bulb when squeezed but it starts OK so kind of doubt that this is a factor but not sure.

 

[Frank Martin]

Re: 1988 V4 OMC - Does Not Want To Idle

clean carbs change recirculation valves check thermostats must have a cylinder head temp of at least 100deg. to idle properly dont overlook even compreshion

 

[Dhadley]

Re: 1988 V4 OMC - Does Not Want To Idle

It's a 2 liter Sea Drive, right? Compression, thermostats and carbs would have been my first suggestion also. You mentioned you put in new plugs. Make sure they are the correct Champions and you are using FRESH fuel less than 30 days old. Does it "spit" back and then quit? Or just fade out?<br /><br />When you say it idles at 6-700 RPM. Is that in neutral or in gear? That sounds about correct if it's in gear. It's normal to idle higher without back pressure. You may want to consider decarbon also. <br /><br />Good luck!

 

[Solittle]

Re: 1988 V4 OMC - Does Not Want To Idle

You guys hit on a possible I haden't thought about and that is the thermostats. I bought the boat about five years ago. The engine was frozen (which I knew when I bought it). I had it rebuilt and my mechanic mentioned that he snipped something from the thermostat to prevent clogging from the salt water crud build-up.<br /><br />I have a temperature guage that indicates that it is running very cool (I have never had any faith in actual readings). I had always thought that you could run into major problems if you ran an engine too hot but had no clue that you could have a problem if it runs too cold. I'll check that first and the other suggestions as well. By the way when it does quit, it just quits. No farting, sneezing or other indication. As I wrote earlier, when you open it up it runs fine.

 

[Down South]

Re: 1988 V4 OMC - Does Not Want To Idle

What is the idle RPM in netrual after it has been warmed up? It may be all you need to do is adjust the idle stop. Warn the engine up and set the idle stop around 800 to 850 RPM. <br />Good luck....