New Mercury 150 Four Stroke running high RPMs

[brocja01]

Guys,

I just got my new Crest Caliber put into the water today and I don't think they calibrated the tach. I'm running WOT at over 7k RPM, and I don't think that can actually be true.

I'm trying to understand what I need to set the pole number on the back of the tach too. I want to make sure they did it correct and that the tach is reading correctly.

I can't imagine, that these guys put a prop so small on this engine as they've sold a zillion of them, a very big dealership. And good people. My Crest was running around 32 mph at WOT, which seems about right, but the tach was pegged passed 7k, can't figure out what's going on.

Any thoughts?

Thanks in advance.
Jeremiah

[mpilot]

[quote="brocja01"]Guys,

I just got my new Crest Caliber put into the water today and I don't think they calibrated the tach. I'm running WOT at over 7k RPM, and I don't think that can actually be true.

I'm trying to understand what I need to set the pole number on the back of the tach too. I want to make sure they did it correct and that the tach is reading correctly.

I can't imagine, that these guys put a prop so small on this engine as they've sold a zillion of them, a very big dealership. And good people. My Crest was running around 32 mph at WOT, which seems about right, but the tach was pegged passed 7k, can't figure out what's going on.

Any thoughts?

Thanks in advance.
Jeremiah[/quote]

Tachometer is out of calibration. The rev limiter would have kicked in. What brad tachometer do you have?

This does happen from time to time. Some manufacturers buy prerigged consoles or rig a bunch at a time and they are off. You can Google your brand tachometer and it should have a chart for the different settings.

[Bamaman]

Or you can just refer it back at your dealer to make the adjustment. You want the tachometer to be working at this point so you can verify that the you've got the correct propeller on your boat.

If you've got a tritoon with lifting strakes, 32 mph is a little slow after the engine's broken in. You should be running at least 37-38 and hopefully 40 mph with the engine trimmed up where the boat's nosecones are out of the water.

My Yamaha has a 6000 rpm redline, and the rev limiter kicks in @ 6300 rpm's.

[brocja01]

I'm glad to hear that my engine has an rev limiter. That makes me feel better. I'm definitely still learning. Yesterday was my first day out on the boat and it is the biggest boat I've ever owned. I'm going to get the brand of my tach, and look up the specs. I didn't think to take a picture of it yesterday.

[DWRAT]

Get a Mercury Smart Craft gauge.
I run a basic SC1000 and it gives you so much info about your motor.
RPM's
Temps
MPG
Trim
And it's $200.

BTW, your motor won't rev past 6000 rpm.

[brocja01]

[quote="DWRAT"]Get a Mercury Smart Craft gauge.
I run a basic SC1000 and it gives you so much info about your motor.
RPM's
Temps
MPG
Trim
And it's $200.

BTW, your motor won't rev past 6000 rpm.[/quote]

I'm thinking about picking up the bluetooth dongle that you hook up that will allow the vessel view application to work. The boat came with a Simrad GO5 XSE. Although, there has to be something I can hook up that will allow the engine stats to come into that as well.

[mpilot]

You probably should be running a 15x15 prop. That's what most tritoons like yours runs.

As for the simrad unit, it should show everything so maybe a trip back to the dealer is in order.

[brocja01]

Hey guys, this is the back of my tach. I think it isn't set up correctly. I'm assuming that the Merc 150 is a 12 pole alternator. If it is, then this is definitely not set up correctly. I would assume all I have to do is set the back of the tach to 5, and I should be good to go.

I agree about a possible trip to the dealer. I don't think they did anything to set up the nav with the engine. I'll need to call them on Tuesday.

[Rick McC.]

Isn't your 150 a four cylinder?

If so; it appears the switch should be set to "1."

The last tach I set for an outboard had a sliding switch on the back, and the setting was based on the number of cylinders.

[brocja01]

I was reading that as poles on my alternator. So you're thinking that I need to set it to one, as my 150 in a 4 cylinder.

I'll give that a shot.

Thanks,
Jeremiah

[mpilot]

I think you were right with setting 5 for 12 poles.

[rancherlee]

Just about every outboard uses the "12 pole" setting.

[Bryden24shp]

Yep, setting 5 for 12 poles is correct!