Mercury 150 Four Stroke Trim issue

[Minnesota Fats]

Hi

I have a 2012 mercury 150 four stroke.  Non Verado.  My issue is that when I hit the trim switch when i'm at speed, the motor bogs significantly.  When I do it at idle, the motor kills.

I have checked the connections at the battery, and the green and blue wires under the cowl.  All were tight and not corroded. 

When the motor is shut off, the down trim sounds normal, but the up trim sounds slow.

The OCV of the battery is 12.4V

The battery voltage when the motor is idling is 13.8V. 

Any ideas?

Thanks!

[TrueNorth]

I would swap a battery to see if there is any difference.  Have you checked the hydraulic fluids? Based on your description, it sounds like something is binding or there is air in the lines.

[Minnesota Fats]

Sorry I forgot to mention I replaced the battery with a new one, and I checked the hydraulic fluid and it was full.

[Hoey]

Maybe a hydraulic pump or motor issue that you could check with am amp meter if you had the specs on the motor.  

I'd check to make sure the pivot points are lubricated, usually a couple of grease zerks.

[Minnesota Fats]

Thanks Hoey.  I don't see any zerks on the trim pivots.  Seems strange.

Good idea on the amperage check, I'll try that next.

[Minnesota Fats]

I checked the amps - about 16-18 when I'm pushing the down button and about 26-32 when I'm pushing the up button.  I checked on both the blue and green wires and got similar results.

I assume the up would be a higher draw than the down, but no idea if it should be this big of a difference.

[Scenic]

Do you have more than one control switch.  I had this issue with mine and my short was in the throttle handle.  When other remote switches were used it worked fine.  

[Minnesota Fats]

I do, there's one on the throttle binnacle and one on the side of the lower motor cowl.  I disconnected the one on the side of the motor and it didn't change anything.  Is there an easy way to disconnect the one on the throttle?  Thanks for the advice!

[Jim Almquist]

Just have someone adjust trim at the motor while running it across the lake to see if the problem changes. I would not disconnect anything until you at least try that to narrow down the problem.

[slammer]

I have '13 model and it does the same thing although it has never died on me while idling and using the trim.  Dealer told me its normal.   They said with such a small pump it has to work hard and draws a lot of power.  Would be interesting to hear from others who own one.

[Minnesota Fats]

Jim - I tried that (using the cowl mounted button while on the lake last weekend) and the same thing happened as when I used the throttle mounted button.

Just for giggles I just went out and rechecked DC amps using both switches and got the same draw.  It is on the trailer and therefore this was checked with the motor off.

Slammer - I know what you are talking about, but this isn't the normal lose a few RPMs - this is like a 1000+ RPM bog.  It didn't do it for the first 3 season I owned it, this is something new.

Edited June 13, 2016 by Minnesota Fats

[TrueNorth]

If the battery is new and the connections at the terminal and at the switches are not corroded, then the only thing I can point to is the pump or hydraulic fluid.  

Raise the motor all the way up and check the fluids.  

If the pump is working hard enough to drop your RPMs at speed or kills it at idle then it's working too hard.  Might just be a bad pump.  

I'll do some research to see if this is an epidemic on the 2012 models.   

[TrueNorth]

Forgot to ask.....aren't you still under warranty?  When talking to your dealer, you could blame the problem on the engine since it dies when you engage the tilt/trim.  They could probably diagnose it in 10 minutes.  

[Minnesota Fats]

Thanks True North

I had already checked the fluid at the full up position - it was full.

Called the dealer, they are going to take it in.  He seemed to think they could figure it out quickly, so that's the next course of action...

 

 

[slammer]

Nephew just bought a new boat with a '15 150  and said his bogs down also when using trim.  It seems like Merc needs to do some reengineering on the lift system.  I checked my fluid tonite and its full.  Look forward to hear what the dealer finds out on yours MN fats.

[slammer]

Dealer find out anything yet?

[Minnesota Fats]

Yes I got it back - turns out it was the ground that comes off the trim motor harness on the starboard side of the engine that is attached to the motor mounting bracket with a small stainless hex head bolt... the wire was damaged somehow but wasn't fully broken.  So they fixed the wire and cleaned the contact and now it works great.

If you have the issue i'd check that ground and make sure its cleaned and tight...

[slammer]

Thanks MN fats.  I cleaned and tightened mine.  Problem gone