Merc Smart Craft // 150 Four Stroke - Question

[muc]

Pretty sure I found it…two blue resistor caps. Plugged wire in…now to make some changes.

Will I need to a system reset on both tachs? Or just Port side?

I don’t know. If it was me doing this. Both tachs.

 

[James211]

Well! EVERYTHING IS WORKING!!! and it’s working better than before. I owe you something…send me your address in a PM and I’ll take care of you. Everybody’s time is worth something.

 

[James211]

The only issue I cannot see to resolve is, the speedometer seems to think I have two fuel tanks, one port and one starboard.l, and it sees the port tank as empty and keeps triggering a silent alarm.

Is the speedometer getting that info from the tachs? I did set each tach up with fuel capacity. Of course this is just occurring to me now and didn’t try disabling the tank on the port tach.

 

[muc]

Happy you got it sorted out! Well mostly I guess, You have "system" gauges. So the speedo is getting it's info straight from the engine ECMs
Not sure what you have going on, the system will read 2 tanks, make sure you select "not installed" for tank 2. Other then that, you could try a master reset on port tach and stop after quick cal 1, skip the cal 2 and see what happens.

Thank you for your kind offer, but I only accept things from people who make $$ off of my advise. Boat owners, I'm happy to help when I can.

If you have some extra $$ laying around (and don't already have this option) I would like to suggest (and this was one of my favorite parts of being a marine tech --- helping customers spend their $$ on neat and sometimes useful stuff) water pressure sensors. Screw a couple of these into your exhaust manifolds and monitor your water pumps.

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www.mercruiserparts.com

I'm curious, did you use the 10 pin harness to connect the J boxes or did you get a 2 pin harness?

And thank you for updating the thread, so many don't once they find the fix!

 

[James211]

I ended up using the two pin harness. A local dealer had the cable.

Part of the reason I added the VVMobile was so I could monitor my engine stats easier than flipping through the screens on the tiny SC1000 screens, I like a visual.

It’s funny mentioned the water pressure sensor, I have one on each engine, but I noticed today that the starboard engine was running a bit warmer at idol and the pressure was a bit lower than the port engine.

Supposedly when I bought the boat two years ago the dealer put new impellers in, and I haven’t put 300hrs on it yet. Not sure if they replaced thermostats or not. My guess is one of three things could be causing it, impeller needs to be replaced, bad sensor or thermostat. I’ve never run the engines into the bottom so I doubt I sucked anything up.

What are your thoughts? Maybe since it’s at idol it’s fine.

 

[alldodge]

Muc is better, but my thought is don't put a lot into the readings. All readings are from electrical (non-calibrated) sensors. If they are a bit off from one another, that is just differences in sensors.

I have 2 new 250 Verado's and the starboard sensors show more fuel, higher temps, and lower oil pressure then port motor. While the port motor when cowling is removed looks pristine, the starboard looks like someone messed with it (cut tie wraps, broken plastic cover).

 

[James211]

Got it, thank you. I tend over think EVERYTHING! Also, I just looked at the PSI specs for water pressure at idol, and it’s within range and it’s peeing. I’ll let it go! Ha!

 

[muc]

I don’t have a lot of hands on experience with the new O/bs, so my mind is stuck in the old 2 strokes. Water pressure was the first thing I added to the ones I owned, but I always had an old speedometer and some pitot hose laying around so it was just another hole in the dash —- still have the conversion chart MPH to PSI.

My recommendation to customers was to call me if the gauge readings change, I told them that the gauges aren’t very accurate but they are very repeatable. So we’re looking for changes in normal readings.

I would look into any difference between motors that is 5% or greater. Especially if it’s something that can affect fueling.

I don’t know what kind of water you boat in. But here in Minnesota I rarely recommended thermostat replacement as a maintenance item on I/Os, but I did recommend them every other impeller change on O/Bs. I don’t know what it is about O/Bs, but they seem to like to eat thermostats. If you don’t know when they were last replaced—- I would suggest you think about them.

got to run, I’ll try to finish my thoughts later.

 

[James211]

Thank you! Out of curiosity, where in MN are you? I’m originally from Red Wing, and have some family near Lake Mille Lacs and Nisswa area. Miss those lakes!