2006 150 optimax rough idle eventually shuts off

[Bigtiny]

If I do it at home on the ear muffs it runs fine but when in the water at no wake speed it will act up. I’ll post a video but it doesn’t shut off in video. It runs fine anything over idle speed. What do you guy think it could be?

https://photos.app.goo.gl/XHrQVaTRSdXw1JxV9

this is a 2.5 liter I was told to repost in this forum.

[JOE54]

do you have to reprime bulb, if so its running outa fuel

[Bigtiny]

do you have to reprime bulb, if so its running outa fuel

havent had to reprime the build in a couple years.

[JOE54]

fuel pressure test will show if its related to restrictions or weak pulse pump

[SilverFox579]

Let me ask Joe's question a different way, are you pumping the bulb before every engine start? If not you should be, especially this time of year. Pulse pump is a possibility for sure, and as Joe indicates, fuel pressure tests will reveal.

[Bigtiny]

Let me ask Joe's question a different way, are you pumping the bulb before every engine start? If not you should be, especially this time of year. Pulse pump is a possibility for sure, and as Joe indicates, fuel pressure tests will reveal.

Ok I didn't know this my last boat I always had to pump the bulb but this one always seems to stay primed so I never worry with it. So you guys are saying I should always pump it.

[SilverFox579]

Before every engine start. A couple quick squeezes will ensure liquid fuel to the pulse pump. If problem continues afterward, then follow Joe54s recommendation.

[EuropeanAM]

If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info when posting. Thanks!

[Bigtiny]

If you would, please take a moment to review the Announcements at the top of the Forum, and be sure to provide the Required Info when posting. Thanks!

thought I did


1. Engine Serial Number=1B262751
2. Year/Make/Model=2006/mercury/optimal
3. Prop you are Running=Tempest plus
4. Current Maximum RPM=5750
5. Idle and WOT Water Pressure Readings=?-sorry
6. Smartcraft or Analog Instruments? =analog
7. Any Engine Mods?=no

[EuropeanAM]

Thanks- Serial number is the only Required item.

Suggest starting with the BASICS:

-Compression Test
-Spark Test
-Fuel Quality, Delivery and Air/Fuel Pressure Tests (as well as pressures at 5/10/15 seconds after shutdown)
-Computer Diagnostic PRINTOUTS of Run History and Freeze Frame (Fault) history
-Maintenance History (and current needs) Review (see FAQ section for Recommended Maintenance for Optimax Models).