Desperate need of help! 96' 150 Merc smoking to MUCH.

[Kblair1985]

1996 150 Mercury Outboard smokes like you're bringing it out of winterization everytime. I have changed 2 check valves on starboard and port side. The merc shop out here basicaly look at me like I'm stupid and say, "well it's a mosqito fogger, and there's nothing to do." ??????????? are you kidding me?! they won't even look at it. Does ANYONE have ANY suqqestions? Please. I'm just waiting for it to blow up or something.
Thanks for your time gentleman.
Keenan

 

[sschefer]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

Is this just when it's started up cold or does it smoke bad all the time?

 

[Kblair1985]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

it's primarily on start up, BUT it has been getting worse and worse and now I can start to see it smoke while running too. It use to disipate after running.
Thanks

 

[sschefer]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

it's primarily on start up, BUT it has been getting worse and worse and now I can start to see it smoke while running too. It use to disipate after running.
Thanks

A couple of things. Sounds like it's running rich and it might be from low compression or low speed stator winding starting to go. Those are things that are easily tested.

On the startup, you can lessen the smoke if you switch to blended synthetic oil such as Penzoil. Don't use the full synthetic just go with the blended.

Another thing is be careful not to over choke it. Squeeze the bulb, turn the key to on, press the choke for 5 seconds, wait a few minutes, squeeze the bulb and start the engine.

Waiting a few minutes after chokeing will allow the fuel to wet the crankcase and it should start without any further chokeing and a lot less smoke.

 

[ClassyGlassy]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

try disconnecting the injector pump system and premix!

 

[aussiejake]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

My 2006 EFI was choking / smoking until I changed the MAP sensor

 

[Kblair1985]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

Anyone else????

 

[j_martin]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

There are 2 check valves on the starboard side. The one on the right is just a mixing T. Which parts did you actually replace?

 

[sschefer]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

1. Air temp sensor - possible suspect. It will richen the engine by 10% if open.
2. MAP sensor - Not a likely suspect. Draw a vacuum on it. This should create a lean condition, if not then replace the ECU the map sensor is not serviceable.
3. Head Temp Sensor - A likely suspect. An open circuit here can cause fuel enrichment up to 40%. It normally stops enrichment at 90 degrees F.
4. Throttle Positioning Sensor (TPI) - A high probability suspect. If it is open it will cause fuel enrichment up to 40% at idle but won't affect WOT.

You can test either the Head or Throttle sensors with a mulitmeter. If they are open (infinite resistance) then they are bad. The TPI can be adjusted but not if it has failed.

Always disconnect the battery prior to performing any work on the EFI system.

 

[j_martin]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

Keenan,
Your thread has only 138 reads and only 6 replies. What's the problem?

#1. Skip the theatrics, threads that read "I'm gonna shoot myself" routinely get skipped if I don't have a lot of time to waste." Title maybe should be something like "{type, like carb'd V6} Merc 150 smokes too much"

2. Give detailed information, detailing exactly what you're seeing, when, and what you've done so far. It helps a lot if you tell us exactly which of the dozen or so merc 150's you own. I've bypassed responding to this thread many times because my crystal ball is broken.

3. Don't carry the conversation to private messages, unless there's a trade to be made or something else like that not allowed on the forum. This is a forum, where I learn a lot along with a gazillion others. When you put something up, lots of people can contribute, lots can learn.

I deleted your private message. Please don't take offense, but I'm not being paid to be your private mechanic.

John

 

[Faztbullet]

Re: Desperate need of help! 96' 150 Merc smoking to MUCH.

As John stated give more information, I myself went back and looked at your earlier posts and you do not say if it is a carb or efi engine. Glad to see MAP sensor fixed your problem "aussiejake" as $75 is a cheap fix now days